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libBF (empty) → 0.5.0

raw patch · 11 files changed

+9927/−0 lines, 11 filesdep +basedep +deepseqdep +libBFsetup-changed

Dependencies added: base, deepseq, libBF

Files

+ CHANGELOG.md view
@@ -0,0 +1,5 @@+# Revision history for libBF-hs++## 0.5.0 -- 2020-07-01++* First version. Released on an unsuspecting world.
+ LICENSE view
@@ -0,0 +1,20 @@+Copyright (c) 2019 Iavor Diatchki++Permission is hereby granted, free of charge, to any person obtaining+a copy of this software and associated documentation files (the+"Software"), to deal in the Software without restriction, including+without limitation the rights to use, copy, modify, merge, publish,+distribute, sublicense, and/or sell copies of the Software, and to+permit persons to whom the Software is furnished to do so, subject to+the following conditions:++The above copyright notice and this permission notice shall be included+in all copies or substantial portions of the Software.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ cbits/libbf-hs.c view
@@ -0,0 +1,16 @@+#include <stdlib.h>+#include "libbf.h"++static+void *libBF_hs_realloc(void *clo, void *ptr, size_t size) {+  return realloc(ptr,size);+}++void bf_context_init_hs(bf_context_t *s) {+  bf_context_init(s, libBF_hs_realloc, NULL);+}++void bf_delete_hs(bf_t *s) {+  bf_delete(s);+}+
+ libBF.cabal view
@@ -0,0 +1,65 @@+cabal-version:       2.2++name:                libBF+version:             0.5.0+synopsis:            A binding to the libBF library.+description:         LibBF is a C library for working with arbitray precision+                     IEEE 754 floating point numbers.+bug-reports:         https://github.com/GaloisInc/libBF-hs/issues+license:             MIT+license-file:        LICENSE+author:              Iavor Diatchki+maintainer:          iavor.diatchki@gmail.com+-- copyright:+category:            Data+extra-source-files:  CHANGELOG.md++source-repository head+  type:     git+  location: https://github.com/GaloisInc/libBF-hs.git++++library+  exposed-modules:+    LibBF,+    LibBF.Opts,+    LibBF.Mutable++  build-depends:+    base >=4.12.0.0 && < 5,+    deepseq++  build-tool-depends:+    hsc2hs:hsc2hs++  hs-source-dirs:      src++  include-dirs:+    libbf-2020-01-19++  includes:+    libbf-2020-01-19/libbf.h++  c-sources:+    libbf-2020-01-19/cutils.c+    libbf-2020-01-19/libbf.c+    cbits/libbf-hs.c++  ghc-options:         -Wall+  default-language:    Haskell2010++executable bf-test+  main-is:            RunUnitTests.hs+  hs-source-dirs:     tests+  build-depends:      base, libBF+  default-language:   Haskell2010+++test-suite libBF-tests+  type:               exitcode-stdio-1.0+  hs-source-dirs:     tests+  main-is:            RunUnitTests.hs+  default-language:   Haskell2010+  build-depends:      base, libBF+
+ libbf-2020-01-19/cutils.c view
@@ -0,0 +1,178 @@+/*+ * C utilities+ * + * Copyright (c) 2017 Fabrice Bellard+ *+ * Permission is hereby granted, free of charge, to any person obtaining a copy+ * of this software and associated documentation files (the "Software"), to deal+ * in the Software without restriction, including without limitation the rights+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell+ * copies of the Software, and to permit persons to whom the Software is+ * furnished to do so, subject to the following conditions:+ *+ * The above copyright notice and this permission notice shall be included in+ * all copies or substantial portions of the Software.+ *+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN+ * THE SOFTWARE.+ */+#include <stdlib.h>+#include <stdio.h>+#include <stdarg.h>+#include <string.h>+#include "cutils.h"++void pstrcpy(char *buf, int buf_size, const char *str)+{+    int c;+    char *q = buf;++    if (buf_size <= 0)+        return;++    for(;;) {+        c = *str++;+        if (c == 0 || q >= buf + buf_size - 1)+            break;+        *q++ = c;+    }+    *q = '\0';+}++/* strcat and truncate. */+char *pstrcat(char *buf, int buf_size, const char *s)+{+    int len;+    len = strlen(buf);+    if (len < buf_size)+        pstrcpy(buf + len, buf_size - len, s);+    return buf;+}++int strstart(const char *str, const char *val, const char **ptr)+{+    const char *p, *q;+    p = str;+    q = val;+    while (*q != '\0') {+        if (*p != *q)+            return 0;+        p++;+        q++;+    }+    if (ptr)+        *ptr = p;+    return 1;+}++void dbuf_init2(DynBuf *s, void *opaque, DynBufReallocFunc *realloc_func)+{+    memset(s, 0, sizeof(*s));+    s->opaque = opaque;+    s->realloc_func = realloc_func;+}++static void *dbuf_default_realloc(void *opaque, void *ptr, size_t size)+{+    return realloc(ptr, size);+}++void dbuf_init(DynBuf *s)+{+    dbuf_init2(s, NULL, dbuf_default_realloc);+}++/* return < 0 if error */+int dbuf_realloc(DynBuf *s, size_t new_size)+{+    size_t size;+    uint8_t *new_buf;+    if (new_size > s->allocated_size) {+        if (s->error)+            return -1;+        size = s->allocated_size * 3 / 2;+        if (size > new_size)+            new_size = size;+        new_buf = s->realloc_func(s->opaque, s->buf, new_size);+        if (!new_buf) {+            s->error = TRUE;+            return -1;+        }+        s->buf = new_buf;+        s->allocated_size = new_size;+    }+    return 0;+}++int dbuf_write(DynBuf *s, size_t offset, const uint8_t *data, size_t len)+{+    size_t end;+    end = offset + len;+    if (dbuf_realloc(s, end))+        return -1;+    memcpy(s->buf + offset, data, len);+    if (end > s->size)+        s->size = end;+    return 0;+}++int dbuf_put(DynBuf *s, const uint8_t *data, size_t len)+{+    if (unlikely((s->size + len) > s->allocated_size)) {+        if (dbuf_realloc(s, s->size + len))+            return -1;+    }+    memcpy(s->buf + s->size, data, len);+    s->size += len;+    return 0;+}++int dbuf_putc(DynBuf *s, uint8_t c)+{+    return dbuf_put(s, &c, 1);+}++int dbuf_putstr(DynBuf *s, const char *str)+{+    return dbuf_put(s, (const uint8_t *)str, strlen(str));+}++int __attribute__((format(printf, 2, 3))) dbuf_printf(DynBuf *s,+                                                      const char *fmt, ...)+{+    va_list ap;+    char buf[128];+    int len;+    +    va_start(ap, fmt);+    len = vsnprintf(buf, sizeof(buf), fmt, ap);+    va_end(ap);+    if (len < sizeof(buf)) {+        /* fast case */+        return dbuf_put(s, (uint8_t *)buf, len);+    } else {+        if (dbuf_realloc(s, s->size + len + 1))+            return -1;+        va_start(ap, fmt);+        vsnprintf((char *)(s->buf + s->size), s->allocated_size - s->size,+                  fmt, ap);+        va_end(ap);+        s->size += len;+    }+    return 0;+}++void dbuf_free(DynBuf *s)+{+    /* we test s->buf as a fail safe to avoid crashing if dbuf_free()+       is called twice */+    if (s->buf) {+        s->realloc_func(s->opaque, s->buf, 0);+    }+    memset(s, 0, sizeof(*s));+}
+ libbf-2020-01-19/libbf.c view
@@ -0,0 +1,8404 @@+/*+ * Tiny arbitrary precision floating point library+ * + * Copyright (c) 2017-2020 Fabrice Bellard+ *+ * Permission is hereby granted, free of charge, to any person obtaining a copy+ * of this software and associated documentation files (the "Software"), to deal+ * in the Software without restriction, including without limitation the rights+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell+ * copies of the Software, and to permit persons to whom the Software is+ * furnished to do so, subject to the following conditions:+ *+ * The above copyright notice and this permission notice shall be included in+ * all copies or substantial portions of the Software.+ *+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN+ * THE SOFTWARE.+ */+#include <stdlib.h>+#include <stdio.h>+#include <inttypes.h>+#include <math.h>+#include <string.h>+#include <assert.h>++#ifdef __AVX2__+#include <immintrin.h>+#endif++#include "cutils.h"+#include "libbf.h"++/* enable it to check the multiplication result */+//#define USE_MUL_CHECK+/* enable it to use FFT/NTT multiplication */+#define USE_FFT_MUL+/* enable decimal floating point support */+#define USE_BF_DEC++//#define inline __attribute__((always_inline))++#ifdef __AVX2__+#define FFT_MUL_THRESHOLD 100 /* in limbs of the smallest factor */+#else+#define FFT_MUL_THRESHOLD 100 /* in limbs of the smallest factor */+#endif++/* XXX: adjust */+#define DIVNORM_LARGE_THRESHOLD 50+#define UDIV1NORM_THRESHOLD 3++#if LIMB_BITS == 64+#define FMT_LIMB1 "%" PRIx64 +#define FMT_LIMB "%016" PRIx64 +#define PRId_LIMB PRId64+#define PRIu_LIMB PRIu64++#else++#define FMT_LIMB1 "%x"+#define FMT_LIMB "%08x"+#define PRId_LIMB "d"+#define PRIu_LIMB "u"++#endif++typedef intptr_t mp_size_t;++typedef int bf_op2_func_t(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                          bf_flags_t flags);++#ifdef USE_FFT_MUL++#define FFT_MUL_R_OVERLAP_A (1 << 0)+#define FFT_MUL_R_OVERLAP_B (1 << 1)+#define FFT_MUL_R_NORESIZE  (1 << 2)++static no_inline int fft_mul(bf_context_t *s,+                             bf_t *res, limb_t *a_tab, limb_t a_len,+                             limb_t *b_tab, limb_t b_len, int mul_flags);+static void fft_clear_cache(bf_context_t *s);+#endif+#ifdef USE_BF_DEC+static limb_t get_digit(const limb_t *tab, limb_t len, slimb_t pos);+#endif+++/* could leading zeros */+static inline int clz(limb_t a)+{+    if (a == 0) {+        return LIMB_BITS;+    } else {+#if LIMB_BITS == 64+        return clz64(a);+#else+        return clz32(a);+#endif+    }+}++static inline int ctz(limb_t a)+{+    if (a == 0) {+        return LIMB_BITS;+    } else {+#if LIMB_BITS == 64+        return ctz64(a);+#else+        return ctz32(a);+#endif+    }+}++static inline int ceil_log2(limb_t a)+{+    if (a <= 1)+        return 0;+    else+        return LIMB_BITS - clz(a - 1);+}++/* b must be >= 1 */+static inline slimb_t ceil_div(slimb_t a, slimb_t b)+{+    if (a >= 0)+        return (a + b - 1) / b;+    else+        return a / b;+}++/* b must be >= 1 */+static inline slimb_t floor_div(slimb_t a, slimb_t b)+{+    if (a >= 0) {+        return a / b;+    } else {+        return (a - b + 1) / b;+    }+}++/* return r = a modulo b (0 <= r <= b - 1. b must be >= 1 */+static inline limb_t smod(slimb_t a, slimb_t b)+{+    a = a % (slimb_t)b;+    if (a < 0)+        a += b;+    return a;+}++/* signed addition with saturation */+static inline slimb_t sat_add(slimb_t a, slimb_t b)+{+    slimb_t r;+    r = a + b;+    /* overflow ? */+    if (((a ^ r) & (b ^ r)) < 0)+        r = (a >> (LIMB_BITS - 1)) ^ (((limb_t)1 << (LIMB_BITS - 1)) - 1);+    return r;+}++#define malloc(s) malloc_is_forbidden(s)+#define free(p) free_is_forbidden(p)+#define realloc(p, s) realloc_is_forbidden(p, s)++void bf_context_init(bf_context_t *s, bf_realloc_func_t *realloc_func,+                     void *realloc_opaque)+{+    memset(s, 0, sizeof(*s));+    s->realloc_func = realloc_func;+    s->realloc_opaque = realloc_opaque;+}++void bf_context_end(bf_context_t *s)+{+    bf_clear_cache(s);+}++void bf_init(bf_context_t *s, bf_t *r)+{+    r->ctx = s;+    r->sign = 0;+    r->expn = BF_EXP_ZERO;+    r->len = 0;+    r->tab = NULL;+}++/* return 0 if OK, -1 if alloc error */+int bf_resize(bf_t *r, limb_t len)+{+    limb_t *tab;+    +    if (len != r->len) {+        tab = bf_realloc(r->ctx, r->tab, len * sizeof(limb_t));+        if (!tab && len != 0)+            return -1;+        r->tab = tab;+        r->len = len;+    }+    return 0;+}++/* return 0 or BF_ST_MEM_ERROR */+int bf_set_ui(bf_t *r, uint64_t a)+{+    r->sign = 0;+    if (a == 0) {+        r->expn = BF_EXP_ZERO;+        bf_resize(r, 0); /* cannot fail */+    } +#if LIMB_BITS == 32+    else if (a <= 0xffffffff)+#else+    else+#endif+    {+        int shift;+        if (bf_resize(r, 1))+            goto fail;+        shift = clz(a);+        r->tab[0] = a << shift;+        r->expn = LIMB_BITS - shift;+    }+#if LIMB_BITS == 32+    else {+        uint32_t a1, a0;+        int shift;+        if (bf_resize(r, 2))+            goto fail;+        a0 = a;+        a1 = a >> 32;+        shift = clz(a1);+        r->tab[0] = a0 << shift;+        r->tab[1] = (a1 << shift) | (a0 >> (LIMB_BITS - shift));+        r->expn = 2 * LIMB_BITS - shift;+    }+#endif+    return 0;+ fail:+    bf_set_nan(r);+    return BF_ST_MEM_ERROR;+}++/* return 0 or BF_ST_MEM_ERROR */+int bf_set_si(bf_t *r, int64_t a)+{+    int ret;++    if (a < 0) {+        ret = bf_set_ui(r, -a);+        r->sign = 1;+    } else {+        ret = bf_set_ui(r, a);+    }+    return ret;+}++void bf_set_nan(bf_t *r)+{+    bf_resize(r, 0); /* cannot fail */+    r->expn = BF_EXP_NAN;+    r->sign = 0;+}++void bf_set_zero(bf_t *r, int is_neg)+{+    bf_resize(r, 0); /* cannot fail */+    r->expn = BF_EXP_ZERO;+    r->sign = is_neg;+}++void bf_set_inf(bf_t *r, int is_neg)+{+    bf_resize(r, 0); /* cannot fail */+    r->expn = BF_EXP_INF;+    r->sign = is_neg;+}++/* return 0 or BF_ST_MEM_ERROR */+int bf_set(bf_t *r, const bf_t *a)+{+    if (r == a)+        return 0;+    if (bf_resize(r, a->len)) {+        bf_set_nan(r);+        return BF_ST_MEM_ERROR;+    }+    r->sign = a->sign;+    r->expn = a->expn;+    memcpy(r->tab, a->tab, a->len * sizeof(limb_t));+    return 0;+}++/* equivalent to bf_set(r, a); bf_delete(a) */+void bf_move(bf_t *r, bf_t *a)+{+    bf_context_t *s = r->ctx;+    if (r == a)+        return;+    bf_free(s, r->tab);+    *r = *a;+}++static limb_t get_limbz(const bf_t *a, limb_t idx)+{+    if (idx >= a->len)+        return 0;+    else+        return a->tab[idx];+}++/* get LIMB_BITS at bit position 'pos' in tab */+static inline limb_t get_bits(const limb_t *tab, limb_t len, slimb_t pos)+{+    limb_t i, a0, a1;+    int p;++    i = pos >> LIMB_LOG2_BITS;+    p = pos & (LIMB_BITS - 1);+    if (i < len)+        a0 = tab[i];+    else+        a0 = 0;+    if (p == 0) {+        return a0;+    } else {+        i++;+        if (i < len)+            a1 = tab[i];+        else+            a1 = 0;+        return (a0 >> p) | (a1 << (LIMB_BITS - p));+    }+}++static inline limb_t get_bit(const limb_t *tab, limb_t len, slimb_t pos)+{+    slimb_t i;+    i = pos >> LIMB_LOG2_BITS;+    if (i < 0 || i >= len)+        return 0;+    return (tab[i] >> (pos & (LIMB_BITS - 1))) & 1;+}++static inline limb_t limb_mask(int start, int last)+{+    limb_t v;+    int n;+    n = last - start + 1;+    if (n == LIMB_BITS)+        v = -1;+    else+        v = (((limb_t)1 << n) - 1) << start;+    return v;+}++static limb_t mp_scan_nz(const limb_t *tab, mp_size_t n)+{+    mp_size_t i;+    for(i = 0; i < n; i++) {+        if (tab[i] != 0)+            return 1;+    }+    return 0;+}++/* return != 0 if one bit between 0 and bit_pos inclusive is not zero. */+static inline limb_t scan_bit_nz(const bf_t *r, slimb_t bit_pos)+{+    slimb_t pos;+    limb_t v;+    +    pos = bit_pos >> LIMB_LOG2_BITS;+    if (pos < 0)+        return 0;+    v = r->tab[pos] & limb_mask(0, bit_pos & (LIMB_BITS - 1));+    if (v != 0)+        return 1;+    pos--;+    while (pos >= 0) {+        if (r->tab[pos] != 0)+            return 1;+        pos--;+    }+    return 0;+}++/* return the addend for rounding. Note that prec can be <= 0 (for+   BF_FLAG_RADPNT_PREC) */+static int bf_get_rnd_add(int *pret, const bf_t *r, limb_t l,+                          slimb_t prec, int rnd_mode)+{+    int add_one, inexact;+    limb_t bit1, bit0;+    +    if (rnd_mode == BF_RNDF) {+        bit0 = 1; /* faithful rounding does not honor the INEXACT flag */+    } else {+        /* starting limb for bit 'prec + 1' */+        bit0 = scan_bit_nz(r, l * LIMB_BITS - 1 - bf_max(0, prec + 1));+    }++    /* get the bit at 'prec' */+    bit1 = get_bit(r->tab, l, l * LIMB_BITS - 1 - prec);+    inexact = (bit1 | bit0) != 0;+    +    add_one = 0;+    switch(rnd_mode) {+    case BF_RNDZ:+        break;+    case BF_RNDN:+        if (bit1) {+            if (bit0) {+                add_one = 1;+            } else {+                /* round to even */+                add_one =+                    get_bit(r->tab, l, l * LIMB_BITS - 1 - (prec - 1));+            }+        }+        break;+    case BF_RNDD:+    case BF_RNDU:+        if (r->sign == (rnd_mode == BF_RNDD))+            add_one = inexact;+        break;+    case BF_RNDA:+        add_one = inexact;+        break;+    case BF_RNDNA:+    case BF_RNDF:+        add_one = bit1;+        break;+    default:+        abort();+    }+    +    if (inexact)+        *pret |= BF_ST_INEXACT;+    return add_one;+}++static int bf_set_overflow(bf_t *r, int sign, limb_t prec, bf_flags_t flags)+{+    slimb_t i, l, e_max;+    int rnd_mode;+    +    rnd_mode = flags & BF_RND_MASK;+    if (prec == BF_PREC_INF ||+        rnd_mode == BF_RNDN ||+        rnd_mode == BF_RNDNA ||+        rnd_mode == BF_RNDA ||+        (rnd_mode == BF_RNDD && sign == 1) ||+        (rnd_mode == BF_RNDU && sign == 0)) {+        bf_set_inf(r, sign);+    } else {+        /* set to maximum finite number */+        l = (prec + LIMB_BITS - 1) / LIMB_BITS;+        if (bf_resize(r, l)) {+            bf_set_nan(r);+            return BF_ST_MEM_ERROR;+        }+        r->tab[0] = limb_mask((-prec) & (LIMB_BITS - 1),+                              LIMB_BITS - 1);+        for(i = 1; i < l; i++)+            r->tab[i] = (limb_t)-1;+        e_max = (limb_t)1 << (bf_get_exp_bits(flags) - 1);+        r->expn = e_max;+        r->sign = sign;+    }+    return BF_ST_OVERFLOW | BF_ST_INEXACT;+}++/* round to prec1 bits assuming 'r' is non zero and finite. 'r' is+   assumed to have length 'l' (1 <= l <= r->len). Note: 'prec1' can be+   infinite (BF_PREC_INF). 'ret' is 0 or BF_ST_INEXACT if the result+   is known to be inexact. Can fail with BF_ST_MEM_ERROR in case of+   overflow not returning infinity. */+static int __bf_round(bf_t *r, limb_t prec1, bf_flags_t flags, limb_t l,+                      int ret)+{+    limb_t v, a;+    int shift, add_one, rnd_mode;+    slimb_t i, bit_pos, pos, e_min, e_max, e_range, prec;++    /* e_min and e_max are computed to match the IEEE 754 conventions */+    e_range = (limb_t)1 << (bf_get_exp_bits(flags) - 1);+    e_min = -e_range + 3;+    e_max = e_range;+    +    if (flags & BF_FLAG_RADPNT_PREC) {+        /* 'prec' is the precision after the radix point */+        if (prec1 != BF_PREC_INF)+            prec = r->expn + prec1;+        else+            prec = prec1;+    } else if (unlikely(r->expn < e_min) && (flags & BF_FLAG_SUBNORMAL)) {+        /* restrict the precision in case of potentially subnormal+           result */+        assert(prec1 != BF_PREC_INF);+        prec = prec1 - (e_min - r->expn);+    } else {+        prec = prec1;+    }++    /* round to prec bits */+    rnd_mode = flags & BF_RND_MASK;+    add_one = bf_get_rnd_add(&ret, r, l, prec, rnd_mode);+    +    if (prec <= 0) {+        if (add_one) {+            bf_resize(r, 1); /* cannot fail */+            r->tab[0] = (limb_t)1 << (LIMB_BITS - 1);+            r->expn += 1 - prec;+            ret |= BF_ST_UNDERFLOW | BF_ST_INEXACT;+            return ret;+        } else {+            goto underflow;+        }+    } else if (add_one) {+        limb_t carry;+        +        /* add one starting at digit 'prec - 1' */+        bit_pos = l * LIMB_BITS - 1 - (prec - 1);+        pos = bit_pos >> LIMB_LOG2_BITS;+        carry = (limb_t)1 << (bit_pos & (LIMB_BITS - 1));+        +        for(i = pos; i < l; i++) {+            v = r->tab[i] + carry;+            carry = (v < carry);+            r->tab[i] = v;+            if (carry == 0)+                break;+        }+        if (carry) {+            /* shift right by one digit */+            v = 1;+            for(i = l - 1; i >= pos; i--) {+                a = r->tab[i];+                r->tab[i] = (a >> 1) | (v << (LIMB_BITS - 1));+                v = a;+            }+            r->expn++;+        }+    }+    +    /* check underflow */+    if (unlikely(r->expn < e_min)) {+        if (flags & BF_FLAG_SUBNORMAL) {+            /* if inexact, also set the underflow flag */+            if (ret & BF_ST_INEXACT)+                ret |= BF_ST_UNDERFLOW;+        } else {+        underflow:+            ret |= BF_ST_UNDERFLOW | BF_ST_INEXACT;+            bf_set_zero(r, r->sign);+            return ret;+        }+    }+    +    /* check overflow */+    if (unlikely(r->expn > e_max))+        return bf_set_overflow(r, r->sign, prec1, flags);+    +    /* keep the bits starting at 'prec - 1' */+    bit_pos = l * LIMB_BITS - 1 - (prec - 1);+    i = bit_pos >> LIMB_LOG2_BITS;+    if (i >= 0) {+        shift = bit_pos & (LIMB_BITS - 1);+        if (shift != 0)+            r->tab[i] &= limb_mask(shift, LIMB_BITS - 1);+    } else {+        i = 0;+    }+    /* remove trailing zeros */+    while (r->tab[i] == 0)+        i++;+    if (i > 0) {+        l -= i;+        memmove(r->tab, r->tab + i, l * sizeof(limb_t));+    }+    bf_resize(r, l); /* cannot fail */+    return ret;+}++/* 'r' must be a finite number. */+int bf_normalize_and_round(bf_t *r, limb_t prec1, bf_flags_t flags)+{+    limb_t l, v, a;+    int shift, ret;+    slimb_t i;+    +    //    bf_print_str("bf_renorm", r);+    l = r->len;+    while (l > 0 && r->tab[l - 1] == 0)+        l--;+    if (l == 0) {+        /* zero */+        r->expn = BF_EXP_ZERO;+        bf_resize(r, 0); /* cannot fail */+        ret = 0;+    } else {+        r->expn -= (r->len - l) * LIMB_BITS;+        /* shift to have the MSB set to '1' */+        v = r->tab[l - 1];+        shift = clz(v);+        if (shift != 0) {+            v = 0;+            for(i = 0; i < l; i++) {+                a = r->tab[i];+                r->tab[i] = (a << shift) | (v >> (LIMB_BITS - shift));+                v = a;+            }+            r->expn -= shift;+        }+        ret = __bf_round(r, prec1, flags, l, 0);+    }+    //    bf_print_str("r_final", r);+    return ret;+}++/* return true if rounding can be done at precision 'prec' assuming+   the exact result r is such that |r-a| <= 2^(EXP(a)-k). */+/* XXX: check the case where the exponent would be incremented by the+   rounding */+int bf_can_round(const bf_t *a, slimb_t prec, bf_rnd_t rnd_mode, slimb_t k)+{+    BOOL is_rndn;+    slimb_t bit_pos, n;+    limb_t bit;+    +    if (a->expn == BF_EXP_INF || a->expn == BF_EXP_NAN)+        return FALSE;+    if (rnd_mode == BF_RNDF) {+        return (k >= (prec + 1));+    }+    if (a->expn == BF_EXP_ZERO)+        return FALSE;+    is_rndn = (rnd_mode == BF_RNDN || rnd_mode == BF_RNDNA);+    if (k < (prec + 2))+        return FALSE;+    bit_pos = a->len * LIMB_BITS - 1 - prec;+    n = k - prec;+    /* bit pattern for RNDN or RNDNA: 0111.. or 1000...+       for other rounding modes: 000... or 111... +    */+    bit = get_bit(a->tab, a->len, bit_pos);+    bit_pos--;+    n--;+    bit ^= is_rndn;+    /* XXX: slow, but a few iterations on average */+    while (n != 0) {+        if (get_bit(a->tab, a->len, bit_pos) != bit)+            return TRUE;+        bit_pos--;+        n--;+    }+    return FALSE;+}++/* Cannot fail with BF_ST_MEM_ERROR. */+int bf_round(bf_t *r, limb_t prec, bf_flags_t flags)+{+    if (r->len == 0)+        return 0;+    return __bf_round(r, prec, flags, r->len, 0);+}++/* for debugging */+static __maybe_unused void dump_limbs(const char *str, const limb_t *tab, limb_t n)+{+    limb_t i;+    printf("%s: len=%" PRId_LIMB "\n", str, n);+    for(i = 0; i < n; i++) {+        printf("%" PRId_LIMB ": " FMT_LIMB "\n",+               i, tab[i]);+    }+}++void mp_print_str(const char *str, const limb_t *tab, limb_t n)+{+    slimb_t i;+    printf("%s= 0x", str);+    for(i = n - 1; i >= 0; i--) {+        if (i != (n - 1))+            printf("_");+        printf(FMT_LIMB, tab[i]);+    }+    printf("\n");+}++static __maybe_unused void mp_print_str_h(const char *str,+                                          const limb_t *tab, limb_t n,+                                          limb_t high)+{+    slimb_t i;+    printf("%s= 0x", str);+    printf(FMT_LIMB, high);+    for(i = n - 1; i >= 0; i--) {+        printf("_");+        printf(FMT_LIMB, tab[i]);+    }+    printf("\n");+}++/* for debugging */+void bf_print_str(const char *str, const bf_t *a)+{+    slimb_t i;+    printf("%s=", str);++    if (a->expn == BF_EXP_NAN) {+        printf("NaN");+    } else {+        if (a->sign)+            putchar('-');+        if (a->expn == BF_EXP_ZERO) {+            putchar('0');+        } else if (a->expn == BF_EXP_INF) {+            printf("Inf");+        } else {+            printf("0x0.");+            for(i = a->len - 1; i >= 0; i--)+                printf(FMT_LIMB, a->tab[i]);+            printf("p%" PRId_LIMB, a->expn);+        }+    }+    printf("\n");+}++/* compare the absolute value of 'a' and 'b'. Return < 0 if a < b, 0+   if a = b and > 0 otherwise. */+int bf_cmpu(const bf_t *a, const bf_t *b)+{+    slimb_t i;+    limb_t len, v1, v2;+    +    if (a->expn != b->expn) {+        if (a->expn < b->expn)+            return -1;+        else+            return 1;+    }+    len = bf_max(a->len, b->len);+    for(i = len - 1; i >= 0; i--) {+        v1 = get_limbz(a, a->len - len + i);+        v2 = get_limbz(b, b->len - len + i);+        if (v1 != v2) {+            if (v1 < v2)+                return -1;+            else+                return 1;+        }+    }+    return 0;+}++/* Full order: -0 < 0, NaN == NaN and NaN is larger than all other numbers */+int bf_cmp_full(const bf_t *a, const bf_t *b)+{+    int res;+    +    if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+        if (a->expn == b->expn)+            res = 0;+        else if (a->expn == BF_EXP_NAN)+            res = 1;+        else+            res = -1;+    } else if (a->sign != b->sign) {+        res = 1 - 2 * a->sign;+    } else {+        res = bf_cmpu(a, b);+        if (a->sign)+            res = -res;+    }+    return res;+}++/* Standard floating point comparison: return 2 if one of the operands+   is NaN (unordered) or -1, 0, 1 depending on the ordering assuming+   -0 == +0 */+int bf_cmp(const bf_t *a, const bf_t *b)+{+    int res;+    +    if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+        res = 2;+    } else if (a->sign != b->sign) {+        if (a->expn == BF_EXP_ZERO && b->expn == BF_EXP_ZERO)+            res = 0;+        else+            res = 1 - 2 * a->sign;+    } else {+        res = bf_cmpu(a, b);+        if (a->sign)+            res = -res;+    }+    return res;+}++/* Compute the number of bits 'n' matching the pattern:+   a= X1000..0+   b= X0111..1+              +   When computing a-b, the result will have at least n leading zero+   bits.++   Precondition: a > b and a.expn - b.expn = 0 or 1+*/+static limb_t count_cancelled_bits(const bf_t *a, const bf_t *b)+{+    slimb_t bit_offset, b_offset, n;+    int p, p1;+    limb_t v1, v2, mask;++    bit_offset = a->len * LIMB_BITS - 1;+    b_offset = (b->len - a->len) * LIMB_BITS - (LIMB_BITS - 1) ++        a->expn - b->expn;+    n = 0;++    /* first search the equals bits */+    for(;;) {+        v1 = get_limbz(a, bit_offset >> LIMB_LOG2_BITS);+        v2 = get_bits(b->tab, b->len, bit_offset + b_offset);+        //        printf("v1=" FMT_LIMB " v2=" FMT_LIMB "\n", v1, v2);+        if (v1 != v2)+            break;+        n += LIMB_BITS;+        bit_offset -= LIMB_BITS;+    }+    /* find the position of the first different bit */+    p = clz(v1 ^ v2) + 1;+    n += p;+    /* then search for '0' in a and '1' in b */+    p = LIMB_BITS - p;+    if (p > 0) {+        /* search in the trailing p bits of v1 and v2 */+        mask = limb_mask(0, p - 1);+        p1 = bf_min(clz(v1 & mask), clz((~v2) & mask)) - (LIMB_BITS - p);+        n += p1;+        if (p1 != p)+            goto done;+    }+    bit_offset -= LIMB_BITS;+    for(;;) {+        v1 = get_limbz(a, bit_offset >> LIMB_LOG2_BITS);+        v2 = get_bits(b->tab, b->len, bit_offset + b_offset);+        //        printf("v1=" FMT_LIMB " v2=" FMT_LIMB "\n", v1, v2);+        if (v1 != 0 || v2 != -1) {+            /* different: count the matching bits */+            p1 = bf_min(clz(v1), clz(~v2));+            n += p1;+            break;+        }+        n += LIMB_BITS;+        bit_offset -= LIMB_BITS;+    }+ done:+    return n;+}++static int bf_add_internal(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                           bf_flags_t flags, int b_neg)+{+    const bf_t *tmp;+    int is_sub, ret, cmp_res, a_sign, b_sign;++    a_sign = a->sign;+    b_sign = b->sign ^ b_neg;+    is_sub = a_sign ^ b_sign;+    cmp_res = bf_cmpu(a, b);+    if (cmp_res < 0) {+        tmp = a;+        a = b;+        b = tmp;+        a_sign = b_sign; /* b_sign is never used later */+    }+    /* abs(a) >= abs(b) */+    if (cmp_res == 0 && is_sub && a->expn < BF_EXP_INF) {+        /* zero result */+        bf_set_zero(r, (flags & BF_RND_MASK) == BF_RNDD);+        ret = 0;+    } else if (a->len == 0 || b->len == 0) {+        ret = 0;+        if (a->expn >= BF_EXP_INF) {+            if (a->expn == BF_EXP_NAN) {+                /* at least one operand is NaN */+                bf_set_nan(r);+            } else if (b->expn == BF_EXP_INF && is_sub) {+                /* infinities with different signs */+                bf_set_nan(r);+                ret = BF_ST_INVALID_OP;+            } else {+                bf_set_inf(r, a_sign);+            }+        } else {+            /* at least one zero and not subtract */+            bf_set(r, a);+            r->sign = a_sign;+            goto renorm;+        }+    } else {+        slimb_t d, a_offset, b_bit_offset, i, cancelled_bits;+        limb_t carry, v1, v2, u, r_len, carry1, precl, tot_len, z, sub_mask;++        r->sign = a_sign;+        r->expn = a->expn;+        d = a->expn - b->expn;+        /* must add more precision for the leading cancelled bits in+           subtraction */+        if (is_sub) {+            if (d <= 1)+                cancelled_bits = count_cancelled_bits(a, b);+            else+                cancelled_bits = 1;+        } else {+            cancelled_bits = 0;+        }+        +        /* add two extra bits for rounding */+        precl = (cancelled_bits + prec + 2 + LIMB_BITS - 1) / LIMB_BITS;+        tot_len = bf_max(a->len, b->len + (d + LIMB_BITS - 1) / LIMB_BITS);+        r_len = bf_min(precl, tot_len);+        if (bf_resize(r, r_len))+            goto fail;+        a_offset = a->len - r_len;+        b_bit_offset = (b->len - r_len) * LIMB_BITS + d;++        /* compute the bits before for the rounding */+        carry = is_sub;+        z = 0;+        sub_mask = -is_sub;+        i = r_len - tot_len;+        while (i < 0) {+            slimb_t ap, bp;+            BOOL inflag;+            +            ap = a_offset + i;+            bp = b_bit_offset + i * LIMB_BITS;+            inflag = FALSE;+            if (ap >= 0 && ap < a->len) {+                v1 = a->tab[ap];+                inflag = TRUE;+            } else {+                v1 = 0;+            }+            if (bp + LIMB_BITS > 0 && bp < (slimb_t)(b->len * LIMB_BITS)) {+                v2 = get_bits(b->tab, b->len, bp);+                inflag = TRUE;+            } else {+                v2 = 0;+            }+            if (!inflag) {+                /* outside 'a' and 'b': go directly to the next value+                   inside a or b so that the running time does not+                   depend on the exponent difference */+                i = 0;+                if (ap < 0)+                    i = bf_min(i, -a_offset);+                /* b_bit_offset + i * LIMB_BITS + LIMB_BITS >= 1+                   equivalent to +                   i >= ceil(-b_bit_offset + 1 - LIMB_BITS) / LIMB_BITS)+                */+                if (bp + LIMB_BITS <= 0)+                    i = bf_min(i, (-b_bit_offset) >> LIMB_LOG2_BITS);+            } else {+                i++;+            }+            v2 ^= sub_mask;+            u = v1 + v2;+            carry1 = u < v1;+            u += carry;+            carry = (u < carry) | carry1;+            z |= u;+        }+        /* and the result */+        for(i = 0; i < r_len; i++) {+            v1 = get_limbz(a, a_offset + i);+            v2 = get_bits(b->tab, b->len, b_bit_offset + i * LIMB_BITS);+            v2 ^= sub_mask;+            u = v1 + v2;+            carry1 = u < v1;+            u += carry;+            carry = (u < carry) | carry1;+            r->tab[i] = u;+        }+        /* set the extra bits for the rounding */+        r->tab[0] |= (z != 0);++        /* carry is only possible in add case */+        if (!is_sub && carry) {+            if (bf_resize(r, r_len + 1))+                goto fail;+            r->tab[r_len] = 1;+            r->expn += LIMB_BITS;+        }+    renorm:+        ret = bf_normalize_and_round(r, prec, flags);+    }+    return ret;+ fail:+    bf_set_nan(r);+    return BF_ST_MEM_ERROR;+}++static int __bf_add(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                     bf_flags_t flags)+{+    return bf_add_internal(r, a, b, prec, flags, 0);+}++static int __bf_sub(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                     bf_flags_t flags)+{+    return bf_add_internal(r, a, b, prec, flags, 1);+}++limb_t mp_add(limb_t *res, const limb_t *op1, const limb_t *op2, +              limb_t n, limb_t carry)+{+    slimb_t i;+    limb_t k, a, v, k1;+    +    k = carry;+    for(i=0;i<n;i++) {+        v = op1[i];+        a = v + op2[i];+        k1 = a < v;+        a = a + k;+        k = (a < k) | k1;+        res[i] = a;+    }+    return k;+}++limb_t mp_add_ui(limb_t *tab, limb_t b, size_t n)+{+    size_t i;+    limb_t k, a;++    k=b;+    for(i=0;i<n;i++) {+        if (k == 0)+            break;+        a = tab[i] + k;+        k = (a < k);+        tab[i] = a;+    }+    return k;+}++limb_t mp_sub(limb_t *res, const limb_t *op1, const limb_t *op2, +              mp_size_t n, limb_t carry)+{+    int i;+    limb_t k, a, v, k1;+    +    k = carry;+    for(i=0;i<n;i++) {+        v = op1[i];+        a = v - op2[i];+        k1 = a > v;+        v = a - k;+        k = (v > a) | k1;+        res[i] = v;+    }+    return k;+}++/* compute 0 - op2 */+static limb_t mp_neg(limb_t *res, const limb_t *op2, mp_size_t n, limb_t carry)+{+    int i;+    limb_t k, a, v, k1;+    +    k = carry;+    for(i=0;i<n;i++) {+        v = 0;+        a = v - op2[i];+        k1 = a > v;+        v = a - k;+        k = (v > a) | k1;+        res[i] = v;+    }+    return k;+}++limb_t mp_sub_ui(limb_t *tab, limb_t b, mp_size_t n)+{+    mp_size_t i;+    limb_t k, a, v;+    +    k=b;+    for(i=0;i<n;i++) {+        v = tab[i];+        a = v - k;+        k = a > v;+        tab[i] = a;+        if (k == 0)+            break;+    }+    return k;+}++/* r = (a + high*B^n) >> shift. Return the remainder r (0 <= r < 2^shift). +   1 <= shift <= LIMB_BITS - 1 */+static limb_t mp_shr(limb_t *tab_r, const limb_t *tab, mp_size_t n, +                     int shift, limb_t high)+{+    mp_size_t i;+    limb_t l, a;++    assert(shift >= 1 && shift < LIMB_BITS);+    l = high;+    for(i = n - 1; i >= 0; i--) {+        a = tab[i];+        tab_r[i] = (a >> shift) | (l << (LIMB_BITS - shift));+        l = a;+    }+    return l & (((limb_t)1 << shift) - 1);+}++/* tabr[] = taba[] * b + l. Return the high carry */+static limb_t mp_mul1(limb_t *tabr, const limb_t *taba, limb_t n, +                      limb_t b, limb_t l)+{+    limb_t i;+    dlimb_t t;++    for(i = 0; i < n; i++) {+        t = (dlimb_t)taba[i] * (dlimb_t)b + l;+        tabr[i] = t;+        l = t >> LIMB_BITS;+    }+    return l;+}++/* tabr[] += taba[] * b, return the high word. */+static limb_t mp_add_mul1(limb_t *tabr, const limb_t *taba, limb_t n,+                          limb_t b)+{+    limb_t i, l;+    dlimb_t t;+    +    l = 0;+    for(i = 0; i < n; i++) {+        t = (dlimb_t)taba[i] * (dlimb_t)b + l + tabr[i];+        tabr[i] = t;+        l = t >> LIMB_BITS;+    }+    return l;+}++/* size of the result : op1_size + op2_size. */+static void mp_mul_basecase(limb_t *result, +                            const limb_t *op1, limb_t op1_size, +                            const limb_t *op2, limb_t op2_size) +{+    limb_t i, r;+    +    result[op1_size] = mp_mul1(result, op1, op1_size, op2[0], 0);+    for(i=1;i<op2_size;i++) {+        r = mp_add_mul1(result + i, op1, op1_size, op2[i]);+        result[i + op1_size] = r;+    }+}++/* return 0 if OK, -1 if memory error */+/* XXX: change API so that result can be allocated */+int mp_mul(bf_context_t *s, limb_t *result, +           const limb_t *op1, limb_t op1_size, +           const limb_t *op2, limb_t op2_size) +{+#ifdef USE_FFT_MUL+    if (unlikely(bf_min(op1_size, op2_size) >= FFT_MUL_THRESHOLD)) {+        bf_t r_s, *r = &r_s;+        r->tab = result;+        /* XXX: optimize memory usage in API */+        if (fft_mul(s, r, (limb_t *)op1, op1_size,+                    (limb_t *)op2, op2_size, FFT_MUL_R_NORESIZE))+            return -1;+    } else+#endif+    {+        mp_mul_basecase(result, op1, op1_size, op2, op2_size);+    }+    return 0;+}++/* tabr[] -= taba[] * b. Return the value to substract to the high+   word. */+static limb_t mp_sub_mul1(limb_t *tabr, const limb_t *taba, limb_t n,+                          limb_t b)+{+    limb_t i, l;+    dlimb_t t;+    +    l = 0;+    for(i = 0; i < n; i++) {+        t = tabr[i] - (dlimb_t)taba[i] * (dlimb_t)b - l;+        tabr[i] = t;+        l = -(t >> LIMB_BITS);+    }+    return l;+}++/* WARNING: d must be >= 2^(LIMB_BITS-1) */+static inline limb_t udiv1norm_init(limb_t d)+{+    limb_t a0, a1;+    a1 = -d - 1;+    a0 = -1;+    return (((dlimb_t)a1 << LIMB_BITS) | a0) / d;+}++/* return the quotient and the remainder in '*pr'of 'a1*2^LIMB_BITS+a0+   / d' with 0 <= a1 < d. */+static inline limb_t udiv1norm(limb_t *pr, limb_t a1, limb_t a0,+                                limb_t d, limb_t d_inv)+{+    limb_t n1m, n_adj, q, r, ah;+    dlimb_t a;+    n1m = ((slimb_t)a0 >> (LIMB_BITS - 1));+    n_adj = a0 + (n1m & d);+    a = (dlimb_t)d_inv * (a1 - n1m) + n_adj;+    q = (a >> LIMB_BITS) + a1;+    /* compute a - q * r and update q so that the remainder is\+       between 0 and d - 1 */+    a = ((dlimb_t)a1 << LIMB_BITS) | a0;+    a = a - (dlimb_t)q * d - d;+    ah = a >> LIMB_BITS;+    q += 1 + ah;+    r = (limb_t)a + (ah & d);+    *pr = r;+    return q;+}++/* b must be >= 1 << (LIMB_BITS - 1) */+static limb_t mp_div1norm(limb_t *tabr, const limb_t *taba, limb_t n,+                          limb_t b, limb_t r)+{+    slimb_t i;++    if (n >= UDIV1NORM_THRESHOLD) {+        limb_t b_inv;+        b_inv = udiv1norm_init(b);+        for(i = n - 1; i >= 0; i--) {+            tabr[i] = udiv1norm(&r, r, taba[i], b, b_inv);+        }+    } else {+        dlimb_t a1;+        for(i = n - 1; i >= 0; i--) {+            a1 = ((dlimb_t)r << LIMB_BITS) | taba[i];+            tabr[i] = a1 / b;+            r = a1 % b;+        }+    }+    return r;+}++static int mp_divnorm_large(bf_context_t *s, +                            limb_t *tabq, limb_t *taba, limb_t na, +                            const limb_t *tabb, limb_t nb);++/* base case division: divides taba[0..na-1] by tabb[0..nb-1]. tabb[nb+   - 1] must be >= 1 << (LIMB_BITS - 1). na - nb must be >= 0. 'taba'+   is modified and contains the remainder (nb limbs). tabq[0..na-nb]+   contains the quotient with tabq[na - nb] <= 1. */+static int mp_divnorm(bf_context_t *s, limb_t *tabq, limb_t *taba, limb_t na, +                      const limb_t *tabb, limb_t nb)+{+    limb_t r, a, c, q, v, b1, b1_inv, n, dummy_r;+    slimb_t i, j;++    b1 = tabb[nb - 1];+    if (nb == 1) {+        taba[0] = mp_div1norm(tabq, taba, na, b1, 0);+        return 0;+    }+    n = na - nb;+    if (bf_min(n, nb) >= DIVNORM_LARGE_THRESHOLD) {+        return mp_divnorm_large(s, tabq, taba, na, tabb, nb);+    }+    +    if (n >= UDIV1NORM_THRESHOLD)+        b1_inv = udiv1norm_init(b1);+    else+        b1_inv = 0;++    /* first iteration: the quotient is only 0 or 1 */+    q = 1;+    for(j = nb - 1; j >= 0; j--) {+        if (taba[n + j] != tabb[j]) {+            if (taba[n + j] < tabb[j])+                q = 0;+            break;+        }+    }+    tabq[n] = q;+    if (q) {+        mp_sub(taba + n, taba + n, tabb, nb, 0);+    }+    +    for(i = n - 1; i >= 0; i--) {+        if (unlikely(taba[i + nb] >= b1)) {+            q = -1;+        } else if (b1_inv) {+            q = udiv1norm(&dummy_r, taba[i + nb], taba[i + nb - 1], b1, b1_inv);+        } else {+            dlimb_t al;+            al = ((dlimb_t)taba[i + nb] << LIMB_BITS) | taba[i + nb - 1];+            q = al / b1;+            r = al % b1;+        }+        r = mp_sub_mul1(taba + i, tabb, nb, q);++        v = taba[i + nb];+        a = v - r;+        c = (a > v);+        taba[i + nb] = a;++        if (c != 0) {+            /* negative result */+            for(;;) {+                q--;+                c = mp_add(taba + i, taba + i, tabb, nb, 0);+                /* propagate carry and test if positive result */+                if (c != 0) {+                    if (++taba[i + nb] == 0) {+                        break;+                    }+                }+            }+        }+        tabq[i] = q;+    }+    return 0;+}++/* compute r=B^(2*n)/a such as a*r < B^(2*n) < a*r + 2 with n >= 1. 'a'+   has n limbs with a[n-1] >= B/2 and 'r' has n+1 limbs with r[n] = 1.+   +   See Modern Computer Arithmetic by Richard P. Brent and Paul+   Zimmermann, algorithm 3.5 */+int mp_recip(bf_context_t *s, limb_t *tabr, const limb_t *taba, limb_t n)+{+    mp_size_t l, h, k, i;+    limb_t *tabxh, *tabt, c, *tabu;+    +    if (n <= 2) {+        /* return ceil(B^(2*n)/a) - 1 */+        /* XXX: could avoid allocation */+        tabu = bf_malloc(s, sizeof(limb_t) * (2 * n + 1));+        tabt = bf_malloc(s, sizeof(limb_t) * (n + 2));+        if (!tabt || !tabu)+            goto fail;+        for(i = 0; i < 2 * n; i++)+            tabu[i] = 0;+        tabu[2 * n] = 1;+        if (mp_divnorm(s, tabt, tabu, 2 * n + 1, taba, n))+            goto fail;+        for(i = 0; i < n + 1; i++)+            tabr[i] = tabt[i];+        if (mp_scan_nz(tabu, n) == 0) {+            /* only happens for a=B^n/2 */+            mp_sub_ui(tabr, 1, n + 1);+        }+    } else {+        l = (n - 1) / 2;+        h = n - l;+        /* n=2p  -> l=p-1, h = p + 1, k = p + 3+           n=2p+1-> l=p,  h = p + 1; k = p + 2+        */+        tabt = bf_malloc(s, sizeof(limb_t) * (n + h + 1));+        tabu = bf_malloc(s, sizeof(limb_t) * (n + 2 * h - l + 2));+        if (!tabt || !tabu)+            goto fail;+        tabxh = tabr + l;+        if (mp_recip(s, tabxh, taba + l, h))+            goto fail;+        if (mp_mul(s, tabt, taba, n, tabxh, h + 1)) /* n + h + 1 limbs */+            goto fail;+        while (tabt[n + h] != 0) {+            mp_sub_ui(tabxh, 1, h + 1);+            c = mp_sub(tabt, tabt, taba, n, 0);+            mp_sub_ui(tabt + n, c, h + 1);+        }+        /* T = B^(n+h) - T */+        mp_neg(tabt, tabt, n + h + 1, 0);+        tabt[n + h]++;+        if (mp_mul(s, tabu, tabt + l, n + h + 1 - l, tabxh, h + 1))+            goto fail;+        /* n + 2*h - l + 2 limbs */+        k = 2 * h - l;+        for(i = 0; i < l; i++)+            tabr[i] = tabu[i + k];+        mp_add(tabr + l, tabr + l, tabu + 2 * h, h, 0);+    }+    bf_free(s, tabt);+    bf_free(s, tabu);+    return 0;+ fail:+    bf_free(s, tabt);+    bf_free(s, tabu);+    return -1;+}++/* return -1, 0 or 1 */+static int mp_cmp(const limb_t *taba, const limb_t *tabb, mp_size_t n)+{+    mp_size_t i;+    for(i = n - 1; i >= 0; i--) {+        if (taba[i] != tabb[i]) {+            if (taba[i] < tabb[i])+                return -1;+            else+                return 1;+        }+    }+    return 0;+}++//#define DEBUG_DIVNORM_LARGE+//#define DEBUG_DIVNORM_LARGE2++/* subquadratic divnorm */+static int mp_divnorm_large(bf_context_t *s, +                            limb_t *tabq, limb_t *taba, limb_t na, +                            const limb_t *tabb, limb_t nb)+{+    limb_t *tabb_inv, nq, *tabt, i, n;+    nq = na - nb;+#ifdef DEBUG_DIVNORM_LARGE+    printf("na=%d nb=%d nq=%d\n", (int)na, (int)nb, (int)nq);+    mp_print_str("a", taba, na);+    mp_print_str("b", tabb, nb);+#endif+    assert(nq >= 1);+    n = nq;+    if (nq < nb)+        n++; +    tabb_inv = bf_malloc(s, sizeof(limb_t) * (n + 1));+    tabt = bf_malloc(s, sizeof(limb_t) * 2 * (n + 1));+    if (!tabb_inv || !tabt)+        goto fail;++    if (n >= nb) {+        for(i = 0; i < n - nb; i++)+            tabt[i] = 0;+        for(i = 0; i < nb; i++)+            tabt[i + n - nb] = tabb[i];+    } else {+        /* truncate B: need to increment it so that the approximate+           inverse is smaller that the exact inverse */+        for(i = 0; i < n; i++)+            tabt[i] = tabb[i + nb - n];+        if (mp_add_ui(tabt, 1, n)) {+            /* tabt = B^n : tabb_inv = B^n */+            memset(tabb_inv, 0, n * sizeof(limb_t));+            tabb_inv[n] = 1;+            goto recip_done;+        }+    }+    if (mp_recip(s, tabb_inv, tabt, n))+        goto fail;+ recip_done:+    /* Q=A*B^-1 */+    if (mp_mul(s, tabt, tabb_inv, n + 1, taba + na - (n + 1), n + 1))+        goto fail;+    +    for(i = 0; i < nq + 1; i++)+        tabq[i] = tabt[i + 2 * (n + 1) - (nq + 1)];+#ifdef DEBUG_DIVNORM_LARGE+    mp_print_str("q", tabq, nq + 1);+#endif++    bf_free(s, tabt);+    bf_free(s, tabb_inv);+    tabb_inv = NULL;+    +    /* R=A-B*Q */+    tabt = bf_malloc(s, sizeof(limb_t) * (na + 1));+    if (!tabt)+        goto fail;+    if (mp_mul(s, tabt, tabq, nq + 1, tabb, nb))+        goto fail;+    /* we add one more limb for the result */+    mp_sub(taba, taba, tabt, nb + 1, 0);+    bf_free(s, tabt);+    /* the approximated quotient is smaller than than the exact one,+       hence we may have to increment it */+#ifdef DEBUG_DIVNORM_LARGE2+    int cnt = 0;+    static int cnt_max;+#endif+    for(;;) {+        if (taba[nb] == 0 && mp_cmp(taba, tabb, nb) < 0)+            break;+        taba[nb] -= mp_sub(taba, taba, tabb, nb, 0);+        mp_add_ui(tabq, 1, nq + 1);+#ifdef DEBUG_DIVNORM_LARGE2+        cnt++;+#endif+    }+#ifdef DEBUG_DIVNORM_LARGE2+    if (cnt > cnt_max) {+        cnt_max = cnt;+        printf("\ncnt=%d nq=%d nb=%d\n", cnt_max, (int)nq, (int)nb);+    }+#endif+    return 0;+ fail:+    bf_free(s, tabb_inv);+    bf_free(s, tabt);+    return -1;+}++int bf_mul(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+           bf_flags_t flags)+{+    int ret, r_sign;++    if (a->len < b->len) {+        const bf_t *tmp = a;+        a = b;+        b = tmp;+    }+    r_sign = a->sign ^ b->sign;+    /* here b->len <= a->len */+    if (b->len == 0) {+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            ret = 0;+        } else if (a->expn == BF_EXP_INF || b->expn == BF_EXP_INF) {+            if ((a->expn == BF_EXP_INF && b->expn == BF_EXP_ZERO) ||+                (a->expn == BF_EXP_ZERO && b->expn == BF_EXP_INF)) {+                bf_set_nan(r);+                ret = BF_ST_INVALID_OP;+            } else {+                bf_set_inf(r, r_sign);+                ret = 0;+            }+        } else {+            bf_set_zero(r, r_sign);+            ret = 0;+        }+    } else {+        bf_t tmp, *r1 = NULL;+        limb_t a_len, b_len, precl;+        limb_t *a_tab, *b_tab;+            +        a_len = a->len;+        b_len = b->len;+        +        if ((flags & BF_RND_MASK) == BF_RNDF) {+            /* faithful rounding does not require using the full inputs */+            precl = (prec + 2 + LIMB_BITS - 1) / LIMB_BITS;+            a_len = bf_min(a_len, precl);+            b_len = bf_min(b_len, precl);+        }+        a_tab = a->tab + a->len - a_len;+        b_tab = b->tab + b->len - b_len;+        +#ifdef USE_FFT_MUL+        if (b_len >= FFT_MUL_THRESHOLD) {+            int mul_flags = 0;+            if (r == a)+                mul_flags |= FFT_MUL_R_OVERLAP_A;+            if (r == b)+                mul_flags |= FFT_MUL_R_OVERLAP_B;+            if (fft_mul(r->ctx, r, a_tab, a_len, b_tab, b_len, mul_flags))+                goto fail;+        } else+#endif+        {+            if (r == a || r == b) {+                bf_init(r->ctx, &tmp);+                r1 = r;+                r = &tmp;+            }+            if (bf_resize(r, a_len + b_len)) {+            fail:+                bf_set_nan(r);+                ret = BF_ST_MEM_ERROR;+                goto done;+            }+            mp_mul_basecase(r->tab, a_tab, a_len, b_tab, b_len);+        }+        r->sign = r_sign;+        r->expn = a->expn + b->expn;+        ret = bf_normalize_and_round(r, prec, flags);+    done:+        if (r == &tmp)+            bf_move(r1, &tmp);+    }+    return ret;+}++/* multiply 'r' by 2^e */+int bf_mul_2exp(bf_t *r, slimb_t e, limb_t prec, bf_flags_t flags)+{+    slimb_t e_max;+    if (r->len == 0)+        return 0;+    e_max = ((limb_t)1 << BF_EXT_EXP_BITS_MAX) - 1;+    e = bf_max(e, -e_max);+    e = bf_min(e, e_max);+    r->expn += e;+    return __bf_round(r, prec, flags, r->len, 0);+}++/* Return e such as a=m*2^e with m odd integer. return 0 if a is zero,+   Infinite or Nan. */+slimb_t bf_get_exp_min(const bf_t *a)+{+    slimb_t i;+    limb_t v;+    int k;+    +    for(i = 0; i < a->len; i++) {+        v = a->tab[i];+        if (v != 0) {+            k = ctz(v);+            return a->expn - (a->len - i) * LIMB_BITS + k;+        }+    }+    return 0;+}++/* a and b must be finite numbers with a >= 0 and b > 0. 'q' is the+   integer defined as floor(a/b) and r = a - q * b. */+static void bf_tdivremu(bf_t *q, bf_t *r,+                        const bf_t *a, const bf_t *b)+{+    if (bf_cmpu(a, b) < 0) {+        bf_set_ui(q, 0);+        bf_set(r, a);+    } else {+        bf_div(q, a, b, bf_max(a->expn - b->expn + 1, 2), BF_RNDZ);+        bf_rint(q, BF_RNDZ);+        bf_mul(r, q, b, BF_PREC_INF, BF_RNDZ);+        bf_sub(r, a, r, BF_PREC_INF, BF_RNDZ);+    }+}++static int __bf_div(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                    bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    int ret, r_sign;+    limb_t n, nb, precl;+    +    r_sign = a->sign ^ b->sign;+    if (a->expn >= BF_EXP_INF || b->expn >= BF_EXP_INF) {+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF && b->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_inf(r, r_sign);+            return 0;+        } else {+            bf_set_zero(r, r_sign);+            return 0;+        }+    } else if (a->expn == BF_EXP_ZERO) {+        if (b->expn == BF_EXP_ZERO) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set_zero(r, r_sign);+            return 0;+        }+    } else if (b->expn == BF_EXP_ZERO) {+        bf_set_inf(r, r_sign);+        return BF_ST_DIVIDE_ZERO;+    }++    /* number of limbs of the quotient (2 extra bits for rounding) */+    precl = (prec + 2 + LIMB_BITS - 1) / LIMB_BITS;+    nb = b->len;+    n = bf_max(a->len, precl);+    +    {+        limb_t *taba, na;+        slimb_t d;+        +        na = n + nb;+        taba = bf_malloc(s, (na + 1) * sizeof(limb_t));+        if (!taba)+            goto fail;+        d = na - a->len;+        memset(taba, 0, d * sizeof(limb_t));+        memcpy(taba + d, a->tab, a->len * sizeof(limb_t));+        if (bf_resize(r, n + 1))+            goto fail;+        if (mp_divnorm(s, r->tab, taba, na, b->tab, nb))+            goto fail;+        +        /* see if non zero remainder */+        if (mp_scan_nz(taba, nb))+            r->tab[0] |= 1;+        bf_free(r->ctx, taba);+        r->expn = a->expn - b->expn + LIMB_BITS;+        r->sign = r_sign;+        ret = bf_normalize_and_round(r, prec, flags);+    }+    return ret;+ fail:+    bf_set_nan(r);+    return BF_ST_MEM_ERROR;+}++/* division and remainder. +   +   rnd_mode is the rounding mode for the quotient. The additional+   rounding mode BF_RND_EUCLIDIAN is supported.++   'q' is an integer. 'r' is rounded with prec and flags (prec can be+   BF_PREC_INF).+*/+int bf_divrem(bf_t *q, bf_t *r, const bf_t *a, const bf_t *b,+              limb_t prec, bf_flags_t flags, int rnd_mode)+{+    bf_t a1_s, *a1 = &a1_s;+    bf_t b1_s, *b1 = &b1_s;+    int q_sign, ret;+    BOOL is_ceil, is_rndn;+    +    assert(q != a && q != b);+    assert(r != a && r != b);+    assert(q != r);+    +    if (a->len == 0 || b->len == 0) {+        bf_set_zero(q, 0);+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF || b->expn == BF_EXP_ZERO) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set(r, a);+            return bf_round(r, prec, flags);+        }+    }++    q_sign = a->sign ^ b->sign;+    is_rndn = (rnd_mode == BF_RNDN || rnd_mode == BF_RNDNA);+    switch(rnd_mode) {+    default:+    case BF_RNDZ:+    case BF_RNDN:+    case BF_RNDNA:+        is_ceil = FALSE;+        break;+    case BF_RNDD:+        is_ceil = q_sign;+        break;+    case BF_RNDU:+        is_ceil = q_sign ^ 1;+        break;+    case BF_RNDA:+        is_ceil = TRUE;+        break;+    case BF_DIVREM_EUCLIDIAN:+        is_ceil = a->sign;+        break;+    }++    a1->expn = a->expn;+    a1->tab = a->tab;+    a1->len = a->len;+    a1->sign = 0;+    +    b1->expn = b->expn;+    b1->tab = b->tab;+    b1->len = b->len;+    b1->sign = 0;++    /* XXX: could improve to avoid having a large 'q' */+    bf_tdivremu(q, r, a1, b1);+    if (bf_is_nan(q) || bf_is_nan(r))+        goto fail;++    if (r->len != 0) {+        if (is_rndn) {+            int res;+            b1->expn--;+            res = bf_cmpu(r, b1);+            b1->expn++;+            if (res > 0 ||+                (res == 0 &&+                 (rnd_mode == BF_RNDNA ||+                  get_bit(q->tab, q->len, q->len * LIMB_BITS - q->expn)))) {+                goto do_sub_r;+            }+        } else if (is_ceil) {+        do_sub_r:+            ret = bf_add_si(q, q, 1, BF_PREC_INF, BF_RNDZ);+            ret |= bf_sub(r, r, b1, BF_PREC_INF, BF_RNDZ);+            if (ret & BF_ST_MEM_ERROR)+                goto fail;+        }+    }++    r->sign ^= a->sign;+    q->sign = q_sign;+    return bf_round(r, prec, flags);+ fail:+    bf_set_nan(q);+    bf_set_nan(r);+    return BF_ST_MEM_ERROR;+}++int bf_rem(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+           bf_flags_t flags, int rnd_mode)+{+    bf_t q_s, *q = &q_s;+    int ret;+    +    bf_init(r->ctx, q);+    ret = bf_divrem(q, r, a, b, prec, flags, rnd_mode);+    bf_delete(q);+    return ret;+}++static inline int bf_get_limb(slimb_t *pres, const bf_t *a, int flags)+{+#if LIMB_BITS == 32+    return bf_get_int32(pres, a, flags);+#else+    return bf_get_int64(pres, a, flags);+#endif+}++int bf_remquo(slimb_t *pq, bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+              bf_flags_t flags, int rnd_mode)+{+    bf_t q_s, *q = &q_s;+    int ret;+    +    bf_init(r->ctx, q);+    ret = bf_divrem(q, r, a, b, prec, flags, rnd_mode);+    bf_get_limb(pq, q, BF_GET_INT_MOD);+    bf_delete(q);+    return ret;+}++static __maybe_unused inline limb_t mul_mod(limb_t a, limb_t b, limb_t m)+{+    dlimb_t t;+    t = (dlimb_t)a * (dlimb_t)b;+    return t % m;+}++#if defined(USE_MUL_CHECK)+static limb_t mp_mod1(const limb_t *tab, limb_t n, limb_t m, limb_t r)+{+    slimb_t i;+    dlimb_t t;++    for(i = n - 1; i >= 0; i--) {+        t = ((dlimb_t)r << LIMB_BITS) | tab[i];+        r = t % m;+    }+    return r;+}+#endif++static const uint16_t sqrt_table[192] = {+128,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,144,145,146,147,148,149,150,150,151,152,153,154,155,155,156,157,158,159,160,160,161,162,163,163,164,165,166,167,167,168,169,170,170,171,172,173,173,174,175,176,176,177,178,178,179,180,181,181,182,183,183,184,185,185,186,187,187,188,189,189,190,191,192,192,193,193,194,195,195,196,197,197,198,199,199,200,201,201,202,203,203,204,204,205,206,206,207,208,208,209,209,210,211,211,212,212,213,214,214,215,215,216,217,217,218,218,219,219,220,221,221,222,222,223,224,224,225,225,226,226,227,227,228,229,229,230,230,231,231,232,232,233,234,234,235,235,236,236,237,237,238,238,239,240,240,241,241,242,242,243,243,244,244,245,245,246,246,247,247,248,248,249,249,250,250,251,251,252,252,253,253,254,254,255,+};++/* a >= 2^(LIMB_BITS - 2).  Return (s, r) with s=floor(sqrt(a)) and+   r=a-s^2. 0 <= r <= 2 * s */+static limb_t mp_sqrtrem1(limb_t *pr, limb_t a)+{+    limb_t s1, r1, s, r, q, u, num;+    +    /* use a table for the 16 -> 8 bit sqrt */+    s1 = sqrt_table[(a >> (LIMB_BITS - 8)) - 64];+    r1 = (a >> (LIMB_BITS - 16)) - s1 * s1;+    if (r1 > 2 * s1) {+        r1 -= 2 * s1 + 1;+        s1++;+    }+    +    /* one iteration to get a 32 -> 16 bit sqrt */+    num = (r1 << 8) | ((a >> (LIMB_BITS - 32 + 8)) & 0xff);+    q = num / (2 * s1); /* q <= 2^8 */+    u = num % (2 * s1);+    s = (s1 << 8) + q;+    r = (u << 8) | ((a >> (LIMB_BITS - 32)) & 0xff);+    r -= q * q;+    if ((slimb_t)r < 0) {+        s--;+        r += 2 * s + 1;+    }++#if LIMB_BITS == 64+    s1 = s;+    r1 = r;+    /* one more iteration for 64 -> 32 bit sqrt */+    num = (r1 << 16) | ((a >> (LIMB_BITS - 64 + 16)) & 0xffff);+    q = num / (2 * s1); /* q <= 2^16 */+    u = num % (2 * s1);+    s = (s1 << 16) + q;+    r = (u << 16) | ((a >> (LIMB_BITS - 64)) & 0xffff);+    r -= q * q;+    if ((slimb_t)r < 0) {+        s--;+        r += 2 * s + 1;+    }+#endif+    *pr = r;+    return s;+}++/* return floor(sqrt(a)) */+limb_t bf_isqrt(limb_t a)+{+    limb_t s, r;+    int k;++    if (a == 0)+        return 0;+    k = clz(a) & ~1;+    s = mp_sqrtrem1(&r, a << k);+    s >>= (k >> 1);+    return s;+}++static limb_t mp_sqrtrem2(limb_t *tabs, limb_t *taba)+{+    limb_t s1, r1, s, q, u, a0, a1;+    dlimb_t r, num;+    int l;++    a0 = taba[0];+    a1 = taba[1];+    s1 = mp_sqrtrem1(&r1, a1);+    l = LIMB_BITS / 2;+    num = ((dlimb_t)r1 << l) | (a0 >> l);+    q = num / (2 * s1);+    u = num % (2 * s1);+    s = (s1 << l) + q;+    r = ((dlimb_t)u << l) | (a0 & (((limb_t)1 << l) - 1));+    if (unlikely((q >> l) != 0))+        r -= (dlimb_t)1 << LIMB_BITS; /* special case when q=2^l */+    else+        r -= q * q;+    if ((slimb_t)(r >> LIMB_BITS) < 0) {+        s--;+        r += 2 * (dlimb_t)s + 1;+    }+    tabs[0] = s;+    taba[0] = r;+    return r >> LIMB_BITS;+}++//#define DEBUG_SQRTREM++/* tmp_buf must contain (n / 2 + 1 limbs). *prh contains the highest+   limb of the remainder. */+static int mp_sqrtrem_rec(bf_context_t *s, limb_t *tabs, limb_t *taba, limb_t n,+                          limb_t *tmp_buf, limb_t *prh)+{+    limb_t l, h, rh, ql, qh, c, i;+    +    if (n == 1) {+        *prh = mp_sqrtrem2(tabs, taba);+        return 0;+    }+#ifdef DEBUG_SQRTREM+    mp_print_str("a", taba, 2 * n);+#endif+    l = n / 2;+    h = n - l;+    if (mp_sqrtrem_rec(s, tabs + l, taba + 2 * l, h, tmp_buf, &qh))+        return -1;+#ifdef DEBUG_SQRTREM+    mp_print_str("s1", tabs + l, h);+    mp_print_str_h("r1", taba + 2 * l, h, qh);+    mp_print_str_h("r2", taba + l, n, qh);+#endif+    +    /* the remainder is in taba + 2 * l. Its high bit is in qh */+    if (qh) {+        mp_sub(taba + 2 * l, taba + 2 * l, tabs + l, h, 0);+    }+    /* instead of dividing by 2*s, divide by s (which is normalized)+       and update q and r */+    if (mp_divnorm(s, tmp_buf, taba + l, n, tabs + l, h))+        return -1;+    qh += tmp_buf[l];+    for(i = 0; i < l; i++)+        tabs[i] = tmp_buf[i];+    ql = mp_shr(tabs, tabs, l, 1, qh & 1);+    qh = qh >> 1; /* 0 or 1 */+    if (ql)+        rh = mp_add(taba + l, taba + l, tabs + l, h, 0);+    else+        rh = 0;+#ifdef DEBUG_SQRTREM+    mp_print_str_h("q", tabs, l, qh);+    mp_print_str_h("u", taba + l, h, rh);+#endif+    +    mp_add_ui(tabs + l, qh, h);+#ifdef DEBUG_SQRTREM+    mp_print_str_h("s2", tabs, n, sh);+#endif+    +    /* q = qh, tabs[l - 1 ... 0], r = taba[n - 1 ... l] */+    /* subtract q^2. if qh = 1 then q = B^l, so we can take shortcuts */+    if (qh) {+        c = qh;+    } else {+        if (mp_mul(s, taba + n, tabs, l, tabs, l))+            return -1;+        c = mp_sub(taba, taba, taba + n, 2 * l, 0);+    }+    rh -= mp_sub_ui(taba + 2 * l, c, n - 2 * l);+    if ((slimb_t)rh < 0) {+        mp_sub_ui(tabs, 1, n);+        rh += mp_add_mul1(taba, tabs, n, 2);+        rh += mp_add_ui(taba, 1, n);+    }+    *prh = rh;+    return 0;+}++/* 'taba' has 2*n limbs with n >= 1 and taba[2*n-1] >= 2 ^ (LIMB_BITS+   - 2). Return (s, r) with s=floor(sqrt(a)) and r=a-s^2. 0 <= r <= 2+   * s. tabs has n limbs. r is returned in the lower n limbs of+   taba. Its r[n] is the returned value of the function. */+/* Algorithm from the article "Karatsuba Square Root" by Paul Zimmermann and+   inspirated from its GMP implementation */+int mp_sqrtrem(bf_context_t *s, limb_t *tabs, limb_t *taba, limb_t n)+{+    limb_t tmp_buf1[8];+    limb_t *tmp_buf;+    mp_size_t n2;+    int ret;+    n2 = n / 2 + 1;+    if (n2 <= countof(tmp_buf1)) {+        tmp_buf = tmp_buf1;+    } else {+        tmp_buf = bf_malloc(s, sizeof(limb_t) * n2);+        if (!tmp_buf)+            return -1;+    }+    ret = mp_sqrtrem_rec(s, tabs, taba, n, tmp_buf, taba + n);+    if (tmp_buf != tmp_buf1)+        bf_free(s, tmp_buf);+    return ret;+}++/* Integer square root with remainder. 'a' must be an integer. r =+   floor(sqrt(a)) and rem = a - r^2.  BF_ST_INEXACT is set if the result+   is inexact. 'rem' can be NULL if the remainder is not needed. */+int bf_sqrtrem(bf_t *r, bf_t *rem1, const bf_t *a)+{+    int ret;+    +    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+        } else if (a->expn == BF_EXP_INF && a->sign) {+            goto invalid_op;+        } else {+            bf_set(r, a);+        }+        if (rem1)+            bf_set_ui(rem1, 0);+        ret = 0;+    } else if (a->sign) {+ invalid_op:+        bf_set_nan(r);+        if (rem1)+            bf_set_ui(rem1, 0);+        ret = BF_ST_INVALID_OP;+    } else {+        bf_t rem_s, *rem;+        +        bf_sqrt(r, a, (a->expn + 1) / 2, BF_RNDZ);+        bf_rint(r, BF_RNDZ);+        /* see if the result is exact by computing the remainder */+        if (rem1) {+            rem = rem1;+        } else {+            rem = &rem_s;+            bf_init(r->ctx, rem);+        }+        /* XXX: could avoid recomputing the remainder */+        bf_mul(rem, r, r, BF_PREC_INF, BF_RNDZ);+        bf_neg(rem);+        bf_add(rem, rem, a, BF_PREC_INF, BF_RNDZ);+        if (bf_is_nan(rem)) {+            ret = BF_ST_MEM_ERROR;+            goto done;+        }+        if (rem->len != 0) {+            ret = BF_ST_INEXACT;+        } else {+            ret = 0;+        }+    done:+        if (!rem1)+            bf_delete(rem);+    }+    return ret;+}++int bf_sqrt(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = a->ctx;+    int ret;++    assert(r != a);++    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+        } else if (a->expn == BF_EXP_INF && a->sign) {+            goto invalid_op;+        } else {+            bf_set(r, a);+        }+        ret = 0;+    } else if (a->sign) {+ invalid_op:+        bf_set_nan(r);+        ret = BF_ST_INVALID_OP;+    } else {+        limb_t *a1;+        slimb_t n, n1;+        limb_t res;+        +        /* convert the mantissa to an integer with at least 2 *+           prec + 4 bits */+        n = (2 * (prec + 2) + 2 * LIMB_BITS - 1) / (2 * LIMB_BITS);+        if (bf_resize(r, n))+            goto fail;+        a1 = bf_malloc(s, sizeof(limb_t) * 2 * n);+        if (!a1)+            goto fail;+        n1 = bf_min(2 * n, a->len);+        memset(a1, 0, (2 * n - n1) * sizeof(limb_t));+        memcpy(a1 + 2 * n - n1, a->tab + a->len - n1, n1 * sizeof(limb_t));+        if (a->expn & 1) {+            res = mp_shr(a1, a1, 2 * n, 1, 0);+        } else {+            res = 0;+        }+        if (mp_sqrtrem(s, r->tab, a1, n)) {+            bf_free(s, a1);+            goto fail;+        }+        if (!res) {+            res = mp_scan_nz(a1, n + 1);+        }+        bf_free(s, a1);+        if (!res) {+            res = mp_scan_nz(a->tab, a->len - n1);+        }+        if (res != 0)+            r->tab[0] |= 1;+        r->sign = 0;+        r->expn = (a->expn + 1) >> 1;+        ret = bf_round(r, prec, flags);+    }+    return ret;+ fail:+    bf_set_nan(r);+    return BF_ST_MEM_ERROR;+}++static no_inline int bf_op2(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+                            bf_flags_t flags, bf_op2_func_t *func)+{+    bf_t tmp;+    int ret;+    +    if (r == a || r == b) {+        bf_init(r->ctx, &tmp);+        ret = func(&tmp, a, b, prec, flags);+        bf_move(r, &tmp);+    } else {+        ret = func(r, a, b, prec, flags);+    }+    return ret;+}++int bf_add(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+            bf_flags_t flags)+{+    return bf_op2(r, a, b, prec, flags, __bf_add);+}++int bf_sub(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+            bf_flags_t flags)+{+    return bf_op2(r, a, b, prec, flags, __bf_sub);+}++int bf_div(bf_t *r, const bf_t *a, const bf_t *b, limb_t prec,+           bf_flags_t flags)+{+    return bf_op2(r, a, b, prec, flags, __bf_div);+}++int bf_mul_ui(bf_t *r, const bf_t *a, uint64_t b1, limb_t prec,+               bf_flags_t flags)+{+    bf_t b;+    int ret;+    bf_init(r->ctx, &b);+    ret = bf_set_ui(&b, b1);+    ret |= bf_mul(r, a, &b, prec, flags);+    bf_delete(&b);+    return ret;+}++int bf_mul_si(bf_t *r, const bf_t *a, int64_t b1, limb_t prec,+               bf_flags_t flags)+{+    bf_t b;+    int ret;+    bf_init(r->ctx, &b);+    ret = bf_set_si(&b, b1);+    ret |= bf_mul(r, a, &b, prec, flags);+    bf_delete(&b);+    return ret;+}++int bf_add_si(bf_t *r, const bf_t *a, int64_t b1, limb_t prec,+              bf_flags_t flags)+{+    bf_t b;+    int ret;+    +    bf_init(r->ctx, &b);+    ret = bf_set_si(&b, b1);+    ret |= bf_add(r, a, &b, prec, flags);+    bf_delete(&b);+    return ret;+}++static int bf_pow_ui(bf_t *r, const bf_t *a, limb_t b, limb_t prec,+                     bf_flags_t flags)+{+    int ret, n_bits, i;+    +    assert(r != a);+    if (b == 0)+        return bf_set_ui(r, 1);+    ret = bf_set(r, a);+    n_bits = LIMB_BITS - clz(b);+    for(i = n_bits - 2; i >= 0; i--) {+        ret |= bf_mul(r, r, r, prec, flags);+        if ((b >> i) & 1)+            ret |= bf_mul(r, r, a, prec, flags);+    }+    return ret;+}++static int bf_pow_ui_ui(bf_t *r, limb_t a1, limb_t b,+                        limb_t prec, bf_flags_t flags)+{+    bf_t a;+    int ret;+    +    if (a1 == 10 && b <= LIMB_DIGITS) {+        /* use precomputed powers. We do not round at this point+           because we expect the caller to do it */+        ret = bf_set_ui(r, mp_pow_dec[b]);+    } else {+        bf_init(r->ctx, &a);+        ret = bf_set_ui(&a, a1);+        ret |= bf_pow_ui(r, &a, b, prec, flags);+        bf_delete(&a);+    }+    return ret;+}++/* convert to integer (infinite precision) */+int bf_rint(bf_t *r, int rnd_mode)+{+    return bf_round(r, 0, rnd_mode | BF_FLAG_RADPNT_PREC);+}++/* logical operations */+#define BF_LOGIC_OR  0+#define BF_LOGIC_XOR 1+#define BF_LOGIC_AND 2++static inline limb_t bf_logic_op1(limb_t a, limb_t b, int op)+{+    switch(op) {+    case BF_LOGIC_OR:+        return a | b;+    case BF_LOGIC_XOR:+        return a ^ b;+    default:+    case BF_LOGIC_AND:+        return a & b;+    }+}++static int bf_logic_op(bf_t *r, const bf_t *a1, const bf_t *b1, int op)+{+    bf_t b1_s, a1_s, *a, *b;+    limb_t a_sign, b_sign, r_sign;+    slimb_t l, i, a_bit_offset, b_bit_offset;+    limb_t v1, v2, v1_mask, v2_mask, r_mask;+    int ret;+    +    assert(r != a1 && r != b1);++    if (a1->expn <= 0)+        a_sign = 0; /* minus zero is considered as positive */+    else+        a_sign = a1->sign;++    if (b1->expn <= 0)+        b_sign = 0; /* minus zero is considered as positive */+    else+        b_sign = b1->sign;+    +    if (a_sign) {+        a = &a1_s;+        bf_init(r->ctx, a);+        if (bf_add_si(a, a1, 1, BF_PREC_INF, BF_RNDZ)) {+            b = NULL;+            goto fail;+        }+    } else {+        a = (bf_t *)a1;+    }++    if (b_sign) {+        b = &b1_s;+        bf_init(r->ctx, b);+        if (bf_add_si(b, b1, 1, BF_PREC_INF, BF_RNDZ))+            goto fail;+    } else {+        b = (bf_t *)b1;+    }+    +    r_sign = bf_logic_op1(a_sign, b_sign, op);+    if (op == BF_LOGIC_AND && r_sign == 0) {+        /* no need to compute extra zeros for and */+        if (a_sign == 0 && b_sign == 0)+            l = bf_min(a->expn, b->expn);+        else if (a_sign == 0)+            l = a->expn;+        else+            l = b->expn;+    } else {+        l = bf_max(a->expn, b->expn);+    }+    /* Note: a or b can be zero */+    l = (bf_max(l, 1) + LIMB_BITS - 1) / LIMB_BITS;+    if (bf_resize(r, l))+        goto fail;+    a_bit_offset = a->len * LIMB_BITS - a->expn;+    b_bit_offset = b->len * LIMB_BITS - b->expn;+    v1_mask = -a_sign;+    v2_mask = -b_sign;+    r_mask = -r_sign;+    for(i = 0; i < l; i++) {+        v1 = get_bits(a->tab, a->len, a_bit_offset + i * LIMB_BITS) ^ v1_mask;+        v2 = get_bits(b->tab, b->len, b_bit_offset + i * LIMB_BITS) ^ v2_mask;+        r->tab[i] = bf_logic_op1(v1, v2, op) ^ r_mask;+    }+    r->expn = l * LIMB_BITS;+    r->sign = r_sign;+    bf_normalize_and_round(r, BF_PREC_INF, BF_RNDZ); /* cannot fail */+    if (r_sign) {+        if (bf_add_si(r, r, -1, BF_PREC_INF, BF_RNDZ))+            goto fail;+    }+    ret = 0;+ done:+    if (a == &a1_s)+        bf_delete(a);+    if (b == &b1_s)+        bf_delete(b);+    return ret;+ fail:+    bf_set_nan(r);+    ret = BF_ST_MEM_ERROR;+    goto done;+}++/* 'a' and 'b' must be integers. Return 0 or BF_ST_MEM_ERROR. */+int bf_logic_or(bf_t *r, const bf_t *a, const bf_t *b)+{+    return bf_logic_op(r, a, b, BF_LOGIC_OR);+}++/* 'a' and 'b' must be integers. Return 0 or BF_ST_MEM_ERROR. */+int bf_logic_xor(bf_t *r, const bf_t *a, const bf_t *b)+{+    return bf_logic_op(r, a, b, BF_LOGIC_XOR);+}++/* 'a' and 'b' must be integers. Return 0 or BF_ST_MEM_ERROR. */+int bf_logic_and(bf_t *r, const bf_t *a, const bf_t *b)+{+    return bf_logic_op(r, a, b, BF_LOGIC_AND);+}++/* conversion between fixed size types */++typedef union {+    double d;+    uint64_t u;+} Float64Union;++int bf_get_float64(const bf_t *a, double *pres, bf_rnd_t rnd_mode)+{+    Float64Union u;+    int e, ret;+    uint64_t m;+    +    ret = 0;+    if (a->expn == BF_EXP_NAN) {+        u.u = 0x7ff8000000000000; /* quiet nan */+    } else {+        bf_t b_s, *b = &b_s;+        +        bf_init(a->ctx, b);+        bf_set(b, a);+        if (bf_is_finite(b)) {+            ret = bf_round(b, 53, rnd_mode | BF_FLAG_SUBNORMAL | bf_set_exp_bits(11));+        }+        if (b->expn == BF_EXP_INF) {+            e = (1 << 11) - 1;+            m = 0;+        } else if (b->expn == BF_EXP_ZERO) {+            e = 0;+            m = 0;+        } else {+            e = b->expn + 1023 - 1;+#if LIMB_BITS == 32+            if (b->len == 2) {+                m = ((uint64_t)b->tab[1] << 32) | b->tab[0];+            } else {+                m = ((uint64_t)b->tab[0] << 32);+            }+#else+            m = b->tab[0];+#endif+            if (e <= 0) {+                /* subnormal */+                m = m >> (12 - e);+                e = 0;+            } else {+                m = (m << 1) >> 12;+            }+        }+        u.u = m | ((uint64_t)e << 52) | ((uint64_t)b->sign << 63);+        bf_delete(b);+    }+    *pres = u.d;+    return ret;+}++int bf_set_float64(bf_t *a, double d)+{+    Float64Union u;+    uint64_t m;+    int shift, e, sgn;+    +    u.d = d;+    sgn = u.u >> 63;+    e = (u.u >> 52) & ((1 << 11) - 1);+    m = u.u & (((uint64_t)1 << 52) - 1);+    if (e == ((1 << 11) - 1)) {+        if (m != 0) {+            bf_set_nan(a);+        } else {+            bf_set_inf(a, sgn);+        }+    } else if (e == 0) {+        if (m == 0) {+            bf_set_zero(a, sgn);+        } else {+            /* subnormal number */+            m <<= 12;+            shift = clz64(m);+            m <<= shift;+            e = -shift;+            goto norm;+        }+    } else {+        m = (m << 11) | ((uint64_t)1 << 63);+    norm:+        a->expn = e - 1023 + 1;+#if LIMB_BITS == 32+        if (bf_resize(a, 2))+            goto fail;+        a->tab[0] = m;+        a->tab[1] = m >> 32;+#else+        if (bf_resize(a, 1))+            goto fail;+        a->tab[0] = m;+#endif+        a->sign = sgn;+    }+    return 0;+fail:+    bf_set_nan(a);+    return BF_ST_MEM_ERROR;+}++/* The rounding mode is always BF_RNDZ. Return BF_ST_OVERFLOW if there+   is an overflow and 0 otherwise. */+int bf_get_int32(int *pres, const bf_t *a, int flags)+{+    uint32_t v;+    int ret;+    if (a->expn >= BF_EXP_INF) {+        ret = 0;+        if (flags & BF_GET_INT_MOD) {+            v = 0;+        } else if (a->expn == BF_EXP_INF) {+            v = (uint32_t)INT32_MAX + a->sign;+            /* XXX: return overflow ? */+        } else {+            v = INT32_MAX;+        }+    } else if (a->expn <= 0) {+        v = 0;+        ret = 0;+    } else if (a->expn <= 31) {+        v = a->tab[a->len - 1] >> (LIMB_BITS - a->expn);+        if (a->sign)+            v = -v;+        ret = 0;+    } else if (!(flags & BF_GET_INT_MOD)) {+        ret = BF_ST_OVERFLOW;+        if (a->sign) {+            v = (uint32_t)INT32_MAX + 1;+            if (a->expn == 32 && +                (a->tab[a->len - 1] >> (LIMB_BITS - 32)) == v) {+                ret = 0;+            }+        } else {+            v = INT32_MAX;+        }+    } else {+        v = get_bits(a->tab, a->len, a->len * LIMB_BITS - a->expn); +        if (a->sign)+            v = -v;+        ret = 0;+    }+    *pres = v;+    return ret;+}++/* The rounding mode is always BF_RNDZ. Return BF_ST_OVERFLOW if there+   is an overflow and 0 otherwise. */+int bf_get_int64(int64_t *pres, const bf_t *a, int flags)+{+    uint64_t v;+    int ret;+    if (a->expn >= BF_EXP_INF) {+        ret = 0;+        if (flags & BF_GET_INT_MOD) {+            v = 0;+        } else if (a->expn == BF_EXP_INF) {+            v = (uint64_t)INT64_MAX + a->sign;+        } else {+            v = INT64_MAX;+        }+    } else if (a->expn <= 0) {+        v = 0;+        ret = 0;+    } else if (a->expn <= 63) {+#if LIMB_BITS == 32+        if (a->expn <= 32)+            v = a->tab[a->len - 1] >> (LIMB_BITS - a->expn);+        else+            v = (((uint64_t)a->tab[a->len - 1] << 32) |+                 get_limbz(a, a->len - 2)) >> (64 - a->expn);+#else+        v = a->tab[a->len - 1] >> (LIMB_BITS - a->expn);+#endif+        if (a->sign)+            v = -v;+        ret = 0;+    } else if (!(flags & BF_GET_INT_MOD)) {+        ret = BF_ST_OVERFLOW;+        if (a->sign) {+            uint64_t v1;+            v = (uint64_t)INT64_MAX + 1;+            if (a->expn == 64) {+                v1 = a->tab[a->len - 1];+#if LIMB_BITS == 32+                v1 = (v1 << 32) | get_limbz(a, a->len - 2);+#endif+                if (v1 == v)+                    ret = 0;+            }+        } else {+            v = INT64_MAX;+        }+    } else {+        slimb_t bit_pos = a->len * LIMB_BITS - a->expn;+        v = get_bits(a->tab, a->len, bit_pos); +#if LIMB_BITS == 32+        v |= (uint64_t)get_bits(a->tab, a->len, bit_pos + 32) << 32;+#endif+        if (a->sign)+            v = -v;+        ret = 0;+    }+    *pres = v;+    return ret;+}++/* base conversion from radix */++static const uint8_t digits_per_limb_table[BF_RADIX_MAX - 1] = {+#if LIMB_BITS == 32+32,20,16,13,12,11,10,10, 9, 9, 8, 8, 8, 8, 8, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,+#else+64,40,32,27,24,22,21,20,19,18,17,17,16,16,16,15,15,15,14,14,14,14,13,13,13,13,13,13,13,12,12,12,12,12,12,+#endif+};++static limb_t get_limb_radix(int radix)+{+    int i, k;+    limb_t radixl;+    +    k = digits_per_limb_table[radix - 2];+    radixl = radix;+    for(i = 1; i < k; i++)+        radixl *= radix;+    return radixl;+}++/* return != 0 if error */+static int bf_integer_from_radix_rec(bf_t *r, const limb_t *tab,+                                     limb_t n, int level, limb_t n0,+                                     limb_t radix, bf_t *pow_tab)+{+    int ret;+    if (n == 1) {+        ret = bf_set_ui(r, tab[0]);+    } else {+        bf_t T_s, *T = &T_s, *B;+        limb_t n1, n2;+        +        n2 = (((n0 * 2) >> (level + 1)) + 1) / 2;+        n1 = n - n2;+        //        printf("level=%d n0=%ld n1=%ld n2=%ld\n", level, n0, n1, n2);+        B = &pow_tab[level];+        if (B->len == 0) {+            ret = bf_pow_ui_ui(B, radix, n2, BF_PREC_INF, BF_RNDZ);+            if (ret)+                return ret;+        }+        ret = bf_integer_from_radix_rec(r, tab + n2, n1, level + 1, n0,+                                        radix, pow_tab);+        if (ret)+            return ret;+        ret = bf_mul(r, r, B, BF_PREC_INF, BF_RNDZ);+        if (ret)+            return ret;+        bf_init(r->ctx, T);+        ret = bf_integer_from_radix_rec(T, tab, n2, level + 1, n0,+                                        radix, pow_tab);+        if (!ret)+            ret = bf_add(r, r, T, BF_PREC_INF, BF_RNDZ);+        bf_delete(T);+    }+    return ret;+    //    bf_print_str("  r=", r);+}++/* return 0 if OK != 0 if memory error */+static int bf_integer_from_radix(bf_t *r, const limb_t *tab,+                                 limb_t n, limb_t radix)+{+    bf_context_t *s = r->ctx;+    int pow_tab_len, i, ret;+    limb_t radixl;+    bf_t *pow_tab;+    +    radixl = get_limb_radix(radix);+    pow_tab_len = ceil_log2(n) + 2; /* XXX: check */+    pow_tab = bf_malloc(s, sizeof(pow_tab[0]) * pow_tab_len);+    if (!pow_tab)+        return -1;+    for(i = 0; i < pow_tab_len; i++)+        bf_init(r->ctx, &pow_tab[i]);+    ret = bf_integer_from_radix_rec(r, tab, n, 0, n, radixl, pow_tab);+    for(i = 0; i < pow_tab_len; i++) {+        bf_delete(&pow_tab[i]);+    }+    bf_free(s, pow_tab);+    return ret;+}++/* compute and round T * radix^expn. */+int bf_mul_pow_radix(bf_t *r, const bf_t *T, limb_t radix,+                     slimb_t expn, limb_t prec, bf_flags_t flags)+{+    int ret, expn_sign, overflow;+    slimb_t e, extra_bits, prec1, ziv_extra_bits;+    bf_t B_s, *B = &B_s;++    if (T->len == 0) {+        return bf_set(r, T);+    } else if (expn == 0) {+        ret = bf_set(r, T);+        ret |= bf_round(r, prec, flags);+        return ret;+    }++    e = expn;+    expn_sign = 0;+    if (e < 0) {+        e = -e;+        expn_sign = 1;+    }+    bf_init(r->ctx, B);+    if (prec == BF_PREC_INF) {+        /* infinite precision: only used if the result is known to be exact */+        ret = bf_pow_ui_ui(B, radix, e, BF_PREC_INF, BF_RNDN);+        if (expn_sign) {+            ret |= bf_div(r, T, B, T->len * LIMB_BITS, BF_RNDN);+        } else {+            ret |= bf_mul(r, T, B, BF_PREC_INF, BF_RNDN);+        }+    } else {+        ziv_extra_bits = 16;+        for(;;) {+            prec1 = prec + ziv_extra_bits;+            /* XXX: correct overflow/underflow handling */+            /* XXX: rigorous error analysis needed */+            extra_bits = ceil_log2(e) * 2 + 1;+            ret = bf_pow_ui_ui(B, radix, e, prec1 + extra_bits, BF_RNDN | BF_FLAG_EXT_EXP);+            overflow = !bf_is_finite(B);+            /* XXX: if bf_pow_ui_ui returns an exact result, can stop+               after the next operation */+            if (expn_sign)+                ret |= bf_div(r, T, B, prec1 + extra_bits, BF_RNDN | BF_FLAG_EXT_EXP);+            else+                ret |= bf_mul(r, T, B, prec1 + extra_bits, BF_RNDN | BF_FLAG_EXT_EXP);+            if (ret & BF_ST_MEM_ERROR)+                break;+            if ((ret & BF_ST_INEXACT) &&+                !bf_can_round(r, prec, flags & BF_RND_MASK, prec1) &&+                !overflow) {+                /* and more precision and retry */+                ziv_extra_bits = ziv_extra_bits  + (ziv_extra_bits / 2);+            } else {+                /* XXX: need to use __bf_round() to pass the inexact+                   flag for the subnormal case */+                ret = bf_round(r, prec, flags) | (ret & BF_ST_INEXACT);+                break;+            }+        }+    }+    bf_delete(B);+    return ret;+}++static inline int to_digit(int c)+{+    if (c >= '0' && c <= '9')+        return c - '0';+    else if (c >= 'A' && c <= 'Z')+        return c - 'A' + 10;+    else if (c >= 'a' && c <= 'z')+        return c - 'a' + 10;+    else+        return 36;+}++/* add a limb at 'pos' and decrement pos. new space is created if+   needed. Return 0 if OK, -1 if memory error */+static int bf_add_limb(bf_t *a, slimb_t *ppos, limb_t v)+{+    slimb_t pos;+    pos = *ppos;+    if (unlikely(pos < 0)) {+        limb_t new_size, d, *new_tab;+        new_size = bf_max(a->len + 1, a->len * 3 / 2);+        new_tab = bf_realloc(a->ctx, a->tab, sizeof(limb_t) * new_size);+        if (!new_tab)+            return -1;+        a->tab = new_tab;+        d = new_size - a->len;+        memmove(a->tab + d, a->tab, a->len * sizeof(limb_t));+        a->len = new_size;+        pos += d;+    }+    a->tab[pos--] = v;+    *ppos = pos;+    return 0;+}++static int bf_tolower(int c)+{+    if (c >= 'A' && c <= 'Z')+        c = c - 'A' + 'a';+    return c;+}++static int strcasestart(const char *str, const char *val, const char **ptr)+{+    const char *p, *q;+    p = str;+    q = val;+    while (*q != '\0') {+        if (bf_tolower(*p) != *q)+            return 0;+        p++;+        q++;+    }+    if (ptr)+        *ptr = p;+    return 1;+}++static int bf_atof_internal(bf_t *r, slimb_t *pexponent,+                            const char *str, const char **pnext, int radix,+                            limb_t prec, bf_flags_t flags, BOOL is_dec)+{+    const char *p, *p_start;+    int is_neg, radix_bits, exp_is_neg, ret, digits_per_limb, shift;+    limb_t cur_limb;+    slimb_t pos, expn, int_len, digit_count;+    BOOL has_decpt, is_bin_exp;+    bf_t a_s, *a;+    +    *pexponent = 0;+    p = str;+    if (!(flags & BF_ATOF_NO_NAN_INF) && radix <= 16 &&+        strcasestart(p, "nan", &p)) {+        bf_set_nan(r);+        ret = 0;+        goto done;+    }+    is_neg = 0;+    +    if (p[0] == '+') {+        p++;+        p_start = p;+    } else if (p[0] == '-') {+        is_neg = 1;+        p++;+        p_start = p;+    } else {+        p_start = p;+    }+    if (p[0] == '0') {+        if ((p[1] == 'x' || p[1] == 'X') &&+            (radix == 0 || radix == 16) &&+            !(flags & BF_ATOF_NO_HEX)) {+            radix = 16;+            p += 2;+        } else if ((p[1] == 'o' || p[1] == 'O') &&+                   radix == 0 && (flags & BF_ATOF_BIN_OCT)) {+            p += 2;+            radix = 8;+        } else if ((p[1] == 'b' || p[1] == 'B') &&+                   radix == 0 && (flags & BF_ATOF_BIN_OCT)) {+            p += 2;+            radix = 2;+        } else {+            goto no_prefix;+        }+        /* there must be a digit after the prefix */+        if (to_digit((uint8_t)*p) >= radix) {+            bf_set_nan(r);+            ret = 0;+            goto done;+        }+    no_prefix: ;+    } else {+        if (!(flags & BF_ATOF_NO_NAN_INF) && radix <= 16 &&+            strcasestart(p, "inf", &p)) {+            bf_set_inf(r, is_neg);+            ret = 0;+            goto done;+        }+    }+    +    if (radix == 0)+        radix = 10;+    if (is_dec) {+        assert(radix == 10);+        radix_bits = 0;+        a = r;+    } else if ((radix & (radix - 1)) != 0) {+        radix_bits = 0; /* base is not a power of two */+        a = &a_s;+        bf_init(r->ctx, a);+    } else {+        radix_bits = ceil_log2(radix);+        a = r;+    }++    /* skip leading zeros */+    /* XXX: could also skip zeros after the decimal point */+    while (*p == '0')+        p++;++    if (radix_bits) {+        shift = digits_per_limb = LIMB_BITS;+    } else {+        radix_bits = 0;+        shift = digits_per_limb = digits_per_limb_table[radix - 2];+    }+    cur_limb = 0;+    bf_resize(a, 1);+    pos = 0;+    has_decpt = FALSE;+    int_len = digit_count = 0;+    for(;;) {+        limb_t c;+        if (*p == '.' && (p > p_start || to_digit(p[1]) < radix)) {+            if (has_decpt)+                break;+            has_decpt = TRUE;+            int_len = digit_count;+            p++;+        }+        c = to_digit(*p);+        if (c >= radix)+            break;+        digit_count++;+        p++;+        if (radix_bits) {+            shift -= radix_bits;+            if (shift <= 0) {+                cur_limb |= c >> (-shift);+                if (bf_add_limb(a, &pos, cur_limb))+                    goto mem_error;+                if (shift < 0)+                    cur_limb = c << (LIMB_BITS + shift);+                else+                    cur_limb = 0;+                shift += LIMB_BITS;+            } else {+                cur_limb |= c << shift;+            }+        } else {+            cur_limb = cur_limb * radix + c;+            shift--;+            if (shift == 0) {+                if (bf_add_limb(a, &pos, cur_limb))+                    goto mem_error;+                shift = digits_per_limb;+                cur_limb = 0;+            }+        }+    }+    if (!has_decpt)+        int_len = digit_count;++    /* add the last limb and pad with zeros */+    if (shift != digits_per_limb) {+        if (radix_bits == 0) {+            while (shift != 0) {+                cur_limb *= radix;+                shift--;+            }+        }+        if (bf_add_limb(a, &pos, cur_limb)) {+        mem_error:+            ret = BF_ST_MEM_ERROR;+            if (!radix_bits)+                bf_delete(a);+            bf_set_nan(r);+            goto done;+        }+    }+            +    /* reset the next limbs to zero (we prefer to reallocate in the+       renormalization) */+    memset(a->tab, 0, (pos + 1) * sizeof(limb_t));++    if (p == p_start) {+        ret = 0;+        if (!radix_bits)+            bf_delete(a);+        bf_set_nan(r);+        goto done;+    }++    /* parse the exponent, if any */+    expn = 0;+    is_bin_exp = FALSE;+    if (((radix == 10 && (*p == 'e' || *p == 'E')) ||+         (radix != 10 && (*p == '@' ||+                          (radix_bits && (*p == 'p' || *p == 'P'))))) &&+        p > p_start) {+        is_bin_exp = (*p == 'p' || *p == 'P');+        p++;+        exp_is_neg = 0;+        if (*p == '+') {+            p++;+        } else if (*p == '-') {+            exp_is_neg = 1;+            p++;+        }+        for(;;) {+            int c;+            c = to_digit(*p);+            if (c >= 10)+                break;+            if (unlikely(expn > ((BF_RAW_EXP_MAX - 2 - 9) / 10))) {+                /* exponent overflow */+                if (exp_is_neg) {+                    bf_set_zero(r, is_neg);+                    ret = BF_ST_UNDERFLOW | BF_ST_INEXACT;+                } else {+                    bf_set_inf(r, is_neg);+                    ret = BF_ST_OVERFLOW | BF_ST_INEXACT;+                }+                goto done;+            }+            p++;+            expn = expn * 10 + c;+        }+        if (exp_is_neg)+            expn = -expn;+    }+    if (is_dec) {+        a->expn = expn + int_len;+        a->sign = is_neg;+        ret = bfdec_normalize_and_round((bfdec_t *)a, prec, flags);+    } else if (radix_bits) {+        /* XXX: may overflow */+        if (!is_bin_exp)+            expn *= radix_bits; +        a->expn = expn + (int_len * radix_bits);+        a->sign = is_neg;+        ret = bf_normalize_and_round(a, prec, flags);+    } else {+        limb_t l;+        pos++;+        l = a->len - pos; /* number of limbs */+        if (l == 0) {+            bf_set_zero(r, is_neg);+            ret = 0;+        } else {+            bf_t T_s, *T = &T_s;++            expn -= l * digits_per_limb - int_len;+            bf_init(r->ctx, T);+            if (bf_integer_from_radix(T, a->tab + pos, l, radix)) {+                bf_set_nan(r);+                ret = BF_ST_MEM_ERROR;+            } else {+                T->sign = is_neg;+                if (flags & BF_ATOF_EXPONENT) {+                    /* return the exponent */+                    *pexponent = expn;+                    ret = bf_set(r, T);+                } else {+                    ret = bf_mul_pow_radix(r, T, radix, expn, prec, flags);+                }+            }+            bf_delete(T);+        }+        bf_delete(a);+    }+ done:+    if (pnext)+        *pnext = p;+    return ret;+}++/* +   Return (status, n, exp). 'status' is the floating point status. 'n'+   is the parsed number. ++   If (flags & BF_ATOF_EXPONENT) and if the radix is not a power of+   two, the parsed number is equal to r *+   (*pexponent)^radix. Otherwise *pexponent = 0.+*/+int bf_atof2(bf_t *r, slimb_t *pexponent,+             const char *str, const char **pnext, int radix,+             limb_t prec, bf_flags_t flags)+{+    return bf_atof_internal(r, pexponent, str, pnext, radix, prec, flags,+                            FALSE);+}++int bf_atof(bf_t *r, const char *str, const char **pnext, int radix,+            limb_t prec, bf_flags_t flags)+{+    slimb_t dummy_exp;+    return bf_atof_internal(r, &dummy_exp, str, pnext, radix, prec, flags, FALSE);+}++/* base conversion to radix */++#if LIMB_BITS == 64+#define RADIXL_10 UINT64_C(10000000000000000000)+#else+#define RADIXL_10 UINT64_C(1000000000)+#endif++static const uint32_t inv_log2_radix[BF_RADIX_MAX - 1][LIMB_BITS / 32 + 1] = {+#if LIMB_BITS == 32+{ 0x80000000, 0x00000000,},+{ 0x50c24e60, 0xd4d4f4a7,},+{ 0x40000000, 0x00000000,},+{ 0x372068d2, 0x0a1ee5ca,},+{ 0x3184648d, 0xb8153e7a,},+{ 0x2d983275, 0x9d5369c4,},+{ 0x2aaaaaaa, 0xaaaaaaab,},+{ 0x28612730, 0x6a6a7a54,},+{ 0x268826a1, 0x3ef3fde6,},+{ 0x25001383, 0xbac8a744,},+{ 0x23b46706, 0x82c0c709,},+{ 0x229729f1, 0xb2c83ded,},+{ 0x219e7ffd, 0xa5ad572b,},+{ 0x20c33b88, 0xda7c29ab,},+{ 0x20000000, 0x00000000,},+{ 0x1f50b57e, 0xac5884b3,},+{ 0x1eb22cc6, 0x8aa6e26f,},+{ 0x1e21e118, 0x0c5daab2,},+{ 0x1d9dcd21, 0x439834e4,},+{ 0x1d244c78, 0x367a0d65,},+{ 0x1cb40589, 0xac173e0c,},+{ 0x1c4bd95b, 0xa8d72b0d,},+{ 0x1bead768, 0x98f8ce4c,},+{ 0x1b903469, 0x050f72e5,},+{ 0x1b3b433f, 0x2eb06f15,},+{ 0x1aeb6f75, 0x9c46fc38,},+{ 0x1aa038eb, 0x0e3bfd17,},+{ 0x1a593062, 0xb38d8c56,},+{ 0x1a15f4c3, 0x2b95a2e6,},+{ 0x19d630dc, 0xcc7ddef9,},+{ 0x19999999, 0x9999999a,},+{ 0x195fec80, 0x8a609431,},+{ 0x1928ee7b, 0x0b4f22f9,},+{ 0x18f46acf, 0x8c06e318,},+{ 0x18c23246, 0xdc0a9f3d,},+#else+{ 0x80000000, 0x00000000, 0x00000000,},+{ 0x50c24e60, 0xd4d4f4a7, 0x021f57bc,},+{ 0x40000000, 0x00000000, 0x00000000,},+{ 0x372068d2, 0x0a1ee5ca, 0x19ea911b,},+{ 0x3184648d, 0xb8153e7a, 0x7fc2d2e1,},+{ 0x2d983275, 0x9d5369c4, 0x4dec1661,},+{ 0x2aaaaaaa, 0xaaaaaaaa, 0xaaaaaaab,},+{ 0x28612730, 0x6a6a7a53, 0x810fabde,},+{ 0x268826a1, 0x3ef3fde6, 0x23e2566b,},+{ 0x25001383, 0xbac8a744, 0x385a3349,},+{ 0x23b46706, 0x82c0c709, 0x3f891718,},+{ 0x229729f1, 0xb2c83ded, 0x15fba800,},+{ 0x219e7ffd, 0xa5ad572a, 0xe169744b,},+{ 0x20c33b88, 0xda7c29aa, 0x9bddee52,},+{ 0x20000000, 0x00000000, 0x00000000,},+{ 0x1f50b57e, 0xac5884b3, 0x70e28eee,},+{ 0x1eb22cc6, 0x8aa6e26f, 0x06d1a2a2,},+{ 0x1e21e118, 0x0c5daab1, 0x81b4f4bf,},+{ 0x1d9dcd21, 0x439834e3, 0x81667575,},+{ 0x1d244c78, 0x367a0d64, 0xc8204d6d,},+{ 0x1cb40589, 0xac173e0c, 0x3b7b16ba,},+{ 0x1c4bd95b, 0xa8d72b0d, 0x5879f25a,},+{ 0x1bead768, 0x98f8ce4c, 0x66cc2858,},+{ 0x1b903469, 0x050f72e5, 0x0cf5488e,},+{ 0x1b3b433f, 0x2eb06f14, 0x8c89719c,},+{ 0x1aeb6f75, 0x9c46fc37, 0xab5fc7e9,},+{ 0x1aa038eb, 0x0e3bfd17, 0x1bd62080,},+{ 0x1a593062, 0xb38d8c56, 0x7998ab45,},+{ 0x1a15f4c3, 0x2b95a2e6, 0x46aed6a0,},+{ 0x19d630dc, 0xcc7ddef9, 0x5aadd61b,},+{ 0x19999999, 0x99999999, 0x9999999a,},+{ 0x195fec80, 0x8a609430, 0xe1106014,},+{ 0x1928ee7b, 0x0b4f22f9, 0x5f69791d,},+{ 0x18f46acf, 0x8c06e318, 0x4d2aeb2c,},+{ 0x18c23246, 0xdc0a9f3d, 0x3fe16970,},+#endif+};++static const limb_t log2_radix[BF_RADIX_MAX - 1] = {+#if LIMB_BITS == 32+0x20000000,+0x32b80347,+0x40000000,+0x4a4d3c26,+0x52b80347,+0x59d5d9fd,+0x60000000,+0x6570068e,+0x6a4d3c26,+0x6eb3a9f0,+0x72b80347,+0x766a008e,+0x79d5d9fd,+0x7d053f6d,+0x80000000,+0x82cc7edf,+0x8570068e,+0x87ef05ae,+0x8a4d3c26,+0x8c8ddd45,+0x8eb3a9f0,+0x90c10501,+0x92b80347,+0x949a784c,+0x966a008e,+0x982809d6,+0x99d5d9fd,+0x9b74948f,+0x9d053f6d,+0x9e88c6b3,+0xa0000000,+0xa16bad37,+0xa2cc7edf,+0xa4231623,+0xa570068e,+#else+0x2000000000000000,+0x32b803473f7ad0f4,+0x4000000000000000,+0x4a4d3c25e68dc57f,+0x52b803473f7ad0f4,+0x59d5d9fd5010b366,+0x6000000000000000,+0x6570068e7ef5a1e8,+0x6a4d3c25e68dc57f,+0x6eb3a9f01975077f,+0x72b803473f7ad0f4,+0x766a008e4788cbcd,+0x79d5d9fd5010b366,+0x7d053f6d26089673,+0x8000000000000000,+0x82cc7edf592262d0,+0x8570068e7ef5a1e8,+0x87ef05ae409a0289,+0x8a4d3c25e68dc57f,+0x8c8ddd448f8b845a,+0x8eb3a9f01975077f,+0x90c10500d63aa659,+0x92b803473f7ad0f4,+0x949a784bcd1b8afe,+0x966a008e4788cbcd,+0x982809d5be7072dc,+0x99d5d9fd5010b366,+0x9b74948f5532da4b,+0x9d053f6d26089673,+0x9e88c6b3626a72aa,+0xa000000000000000,+0xa16bad3758efd873,+0xa2cc7edf592262d0,+0xa4231623369e78e6,+0xa570068e7ef5a1e8,+#endif+};++/* compute floor(a*b) or ceil(a*b) with b = log2(radix) or+   b=1/log2(radix). For is_inv = 0, strict accuracy is not guaranteed+   when radix is not a power of two. */+slimb_t bf_mul_log2_radix(slimb_t a1, unsigned int radix, int is_inv,+                          int is_ceil1)+{+    int is_neg;+    limb_t a;+    BOOL is_ceil;++    is_ceil = is_ceil1;+    a = a1;+    if (a1 < 0) {+        a = -a;+        is_neg = 1;+    } else {+        is_neg = 0;+    }+    is_ceil ^= is_neg;+    if ((radix & (radix - 1)) == 0) {+        int radix_bits;+        /* radix is a power of two */+        radix_bits = ceil_log2(radix);+        if (is_inv) {+            if (is_ceil)+                a += radix_bits - 1;+            a = a / radix_bits;+        } else {+            a = a * radix_bits;+        }+    } else {+        const uint32_t *tab;+        limb_t b0, b1;+        dlimb_t t;+        +        if (is_inv) {+            tab = inv_log2_radix[radix - 2];+#if LIMB_BITS == 32+            b1 = tab[0];+            b0 = tab[1];+#else+            b1 = ((limb_t)tab[0] << 32) | tab[1];+            b0 = (limb_t)tab[2] << 32;+#endif+            t = (dlimb_t)b0 * (dlimb_t)a;+            t = (dlimb_t)b1 * (dlimb_t)a + (t >> LIMB_BITS);+            a = t >> (LIMB_BITS - 1);+        } else {+            b0 = log2_radix[radix - 2];+            t = (dlimb_t)b0 * (dlimb_t)a;+            a = t >> (LIMB_BITS - 3);+        }+        /* a = floor(result) and 'result' cannot be an integer */+        a += is_ceil;+    }+    if (is_neg)+        a = -a;+    return a;+}++/* 'n' is the number of output limbs */+static void bf_integer_to_radix_rec(bf_t *pow_tab,+                                    limb_t *out, const bf_t *a, limb_t n,+                                    int level, limb_t n0, limb_t radixl,+                                    unsigned int radixl_bits)+{+    limb_t n1, n2, q_prec;+    assert(n >= 1);+    if (n == 1) {+        out[0] = get_bits(a->tab, a->len, a->len * LIMB_BITS - a->expn);+    } else if (n == 2) {+        dlimb_t t;+        slimb_t pos;+        pos = a->len * LIMB_BITS - a->expn;+        t = ((dlimb_t)get_bits(a->tab, a->len, pos + LIMB_BITS) << LIMB_BITS) |+            get_bits(a->tab, a->len, pos);+        if (likely(radixl == RADIXL_10)) {+            /* use division by a constant when possible */+            out[0] = t % RADIXL_10;+            out[1] = t / RADIXL_10;+        } else {+            out[0] = t % radixl;+            out[1] = t / radixl;+        }+    } else {+        bf_t Q, R, *B, *B_inv;+        int q_add;+        bf_init(a->ctx, &Q);+        bf_init(a->ctx, &R);+        n2 = (((n0 * 2) >> (level + 1)) + 1) / 2;+        n1 = n - n2;+        B = &pow_tab[2 * level];+        B_inv = &pow_tab[2 * level + 1];+        if (B->len == 0) {+            /* compute BASE^n2 */+            bf_pow_ui_ui(B, radixl, n2, BF_PREC_INF, BF_RNDZ);+            /* we use enough bits for the maximum possible 'n1' value,+               i.e. n2 + 1 */+            bf_set_ui(&R, 1);+            bf_div(B_inv, &R, B, (n2 + 1) * radixl_bits + 2, BF_RNDN);+        }+        //        printf("%d: n1=% " PRId64 " n2=%" PRId64 "\n", level, n1, n2);+        q_prec = n1 * radixl_bits;+        bf_mul(&Q, a, B_inv, q_prec, BF_RNDN);+        bf_rint(&Q, BF_RNDZ);+        +        bf_mul(&R, &Q, B, BF_PREC_INF, BF_RNDZ);+        bf_sub(&R, a, &R, BF_PREC_INF, BF_RNDZ);+        /* adjust if necessary */+        q_add = 0;+        while (R.sign && R.len != 0) {+            bf_add(&R, &R, B, BF_PREC_INF, BF_RNDZ);+            q_add--;+        }+        while (bf_cmpu(&R, B) >= 0) {+            bf_sub(&R, &R, B, BF_PREC_INF, BF_RNDZ);+            q_add++;+        }+        if (q_add != 0) {+            bf_add_si(&Q, &Q, q_add, BF_PREC_INF, BF_RNDZ);+        }+        bf_integer_to_radix_rec(pow_tab, out + n2, &Q, n1, level + 1, n0,+                                radixl, radixl_bits);+        bf_integer_to_radix_rec(pow_tab, out, &R, n2, level + 1, n0,+                                radixl, radixl_bits);+        bf_delete(&Q);+        bf_delete(&R);+    }+}++static void bf_integer_to_radix(bf_t *r, const bf_t *a, limb_t radixl)+{+    bf_context_t *s = r->ctx;+    limb_t r_len;+    bf_t *pow_tab;+    int i, pow_tab_len;+    +    r_len = r->len;+    pow_tab_len = (ceil_log2(r_len) + 2) * 2; /* XXX: check */+    pow_tab = bf_malloc(s, sizeof(pow_tab[0]) * pow_tab_len);+    for(i = 0; i < pow_tab_len; i++)+        bf_init(r->ctx, &pow_tab[i]);++    bf_integer_to_radix_rec(pow_tab, r->tab, a, r_len, 0, r_len, radixl,+                            ceil_log2(radixl));++    for(i = 0; i < pow_tab_len; i++) {+        bf_delete(&pow_tab[i]);+    }+    bf_free(s, pow_tab);+}++/* a must be >= 0. 'P' is the wanted number of digits in radix+   'radix'. 'r' is the mantissa represented as an integer. *pE+   contains the exponent. Return != 0 if memory error. */+static int bf_convert_to_radix(bf_t *r, slimb_t *pE,+                               const bf_t *a, int radix,+                               limb_t P, bf_rnd_t rnd_mode,+                               BOOL is_fixed_exponent)+{+    slimb_t E, e, prec, extra_bits, ziv_extra_bits, prec0;+    bf_t B_s, *B = &B_s;+    int e_sign, ret, res;+    +    if (a->len == 0) {+        /* zero case */+        *pE = 0;+        return bf_set(r, a);+    }++    if (is_fixed_exponent) {+        E = *pE;+    } else {+        /* compute the new exponent */+        E = 1 + bf_mul_log2_radix(a->expn - 1, radix, TRUE, FALSE);+    }+    //    bf_print_str("a", a);+    //    printf("E=%ld P=%ld radix=%d\n", E, P, radix);+    +    for(;;) {+        e = P - E;+        e_sign = 0;+        if (e < 0) {+            e = -e;+            e_sign = 1;+        }+        /* Note: precision for log2(radix) is not critical here */+        prec0 = bf_mul_log2_radix(P, radix, FALSE, TRUE);+        ziv_extra_bits = 16;+        for(;;) {+            prec = prec0 + ziv_extra_bits;+            /* XXX: rigorous error analysis needed */+            extra_bits = ceil_log2(e) * 2 + 1;+            ret = bf_pow_ui_ui(r, radix, e, prec + extra_bits,+                               BF_RNDN | BF_FLAG_EXT_EXP);+            if (!e_sign)+                ret |= bf_mul(r, r, a, prec + extra_bits,+                              BF_RNDN | BF_FLAG_EXT_EXP);+            else+                ret |= bf_div(r, a, r, prec + extra_bits,+                              BF_RNDN | BF_FLAG_EXT_EXP);+            if (ret & BF_ST_MEM_ERROR)+                return BF_ST_MEM_ERROR;+            /* if the result is not exact, check that it can be safely+               rounded to an integer */+            if ((ret & BF_ST_INEXACT) &&+                !bf_can_round(r, r->expn, rnd_mode, prec)) {+                /* and more precision and retry */+                ziv_extra_bits = ziv_extra_bits  + (ziv_extra_bits / 2);+                continue;+            } else {+                ret = bf_rint(r, rnd_mode);+                if (ret & BF_ST_MEM_ERROR)+                    return BF_ST_MEM_ERROR;+                break;+            }+        }+        if (is_fixed_exponent)+            break;+        /* check that the result is < B^P */+        /* XXX: do a fast approximate test first ? */+        bf_init(r->ctx, B);+        ret = bf_pow_ui_ui(B, radix, P, BF_PREC_INF, BF_RNDZ);+        if (ret) {+            bf_delete(B);+            return ret;+        }+        res = bf_cmpu(r, B);+        bf_delete(B);+        if (res < 0)+            break;+        /* try a larger exponent */+        E++;+    }+    *pE = E;+    return 0;+}++static void limb_to_a(char *buf, limb_t n, unsigned int radix, int len)+{+    int digit, i;++    if (radix == 10) {+        /* specific case with constant divisor */+        for(i = len - 1; i >= 0; i--) {+            digit = (limb_t)n % 10;+            n = (limb_t)n / 10;+            buf[i] = digit + '0';+        }+    } else {+        for(i = len - 1; i >= 0; i--) {+            digit = (limb_t)n % radix;+            n = (limb_t)n / radix;+            if (digit < 10)+                digit += '0';+            else+                digit += 'a' - 10;+            buf[i] = digit;+        }+    }+}++/* for power of 2 radixes */+static void limb_to_a2(char *buf, limb_t n, unsigned int radix_bits, int len)+{+    int digit, i;+    unsigned int mask;++    mask = (1 << radix_bits) - 1;+    for(i = len - 1; i >= 0; i--) {+        digit = n & mask;+        n >>= radix_bits;+        if (digit < 10)+            digit += '0';+        else+            digit += 'a' - 10;+        buf[i] = digit;+    }+}++/* 'a' must be an integer if the is_dec = FALSE or if the radix is not+   a power of two. A dot is added before the 'dot_pos' digit. dot_pos+   = n_digits does not display the dot. 0 <= dot_pos <=+   n_digits. n_digits >= 1. */+static void output_digits(DynBuf *s, const bf_t *a1, int radix, limb_t n_digits,+                          limb_t dot_pos, BOOL is_dec)+{+    limb_t i, v, l;+    slimb_t pos, pos_incr;+    int digits_per_limb, buf_pos, radix_bits, first_buf_pos;+    char buf[65];+    bf_t a_s, *a;++    if (is_dec) {+        digits_per_limb = LIMB_DIGITS;+        a = (bf_t *)a1;+        radix_bits = 0;+        pos = a->len;+        pos_incr = 1;+        first_buf_pos = 0;+    } else if ((radix & (radix - 1)) == 0) {+        a = (bf_t *)a1;+        radix_bits = ceil_log2(radix);+        digits_per_limb = LIMB_BITS / radix_bits;+        pos_incr = digits_per_limb * radix_bits;+        /* digits are aligned relative to the radix point */+        pos = a->len * LIMB_BITS + smod(-a->expn, radix_bits);+        first_buf_pos = 0;+    } else {+        limb_t n, radixl;++        digits_per_limb = digits_per_limb_table[radix - 2];+        radixl = get_limb_radix(radix);+        a = &a_s;+        bf_init(a1->ctx, a);+        n = (n_digits + digits_per_limb - 1) / digits_per_limb;+        bf_resize(a, n);+        bf_integer_to_radix(a, a1, radixl);+        radix_bits = 0;+        pos = n;+        pos_incr = 1;+        first_buf_pos = pos * digits_per_limb - n_digits;+    }+    buf_pos = digits_per_limb;+    i = 0;+    while (i < n_digits) {+        if (buf_pos == digits_per_limb) {+            pos -= pos_incr;+            if (radix_bits == 0) {+                v = get_limbz(a, pos);+                limb_to_a(buf, v, radix, digits_per_limb);+            } else {+                v = get_bits(a->tab, a->len, pos);+                limb_to_a2(buf, v, radix_bits, digits_per_limb);+            }+            buf_pos = first_buf_pos;+            first_buf_pos = 0;+        }+        if (i < dot_pos) {+            l = dot_pos;+        } else {+            if (i == dot_pos)+                dbuf_putc(s, '.');+            l = n_digits;+        }+        l = bf_min(digits_per_limb - buf_pos, l - i);+        dbuf_put(s, (uint8_t *)(buf + buf_pos), l);+        buf_pos += l;+        i += l;+    }+    if (a != a1)+        bf_delete(a);+}++static void *bf_dbuf_realloc(void *opaque, void *ptr, size_t size)+{+    bf_context_t *s = opaque;+    return bf_realloc(s, ptr, size);+}++/* return the length in bytes. A trailing '\0' is added */+static char *bf_ftoa_internal(size_t *plen, const bf_t *a2, int radix,+                              limb_t prec, bf_flags_t flags, BOOL is_dec)+{+    bf_context_t *ctx = a2->ctx;+    DynBuf s_s, *s = &s_s;+    int radix_bits;+    +    //    bf_print_str("ftoa", a2);+    //    printf("radix=%d\n", radix);+    dbuf_init2(s, ctx, bf_dbuf_realloc);+    if (a2->expn == BF_EXP_NAN) {+        dbuf_putstr(s, "NaN");+    } else {+        if (a2->sign)+            dbuf_putc(s, '-');+        if (a2->expn == BF_EXP_INF) {+            if (flags & BF_FTOA_JS_QUIRKS)+                dbuf_putstr(s, "Infinity");+            else+                dbuf_putstr(s, "Inf");+        } else {+            int fmt, ret;+            slimb_t n_digits, n, i, n_max, n1;+            bf_t a1_s, *a1 = &a1_s;++            if ((radix & (radix - 1)) != 0)+                radix_bits = 0;+            else+                radix_bits = ceil_log2(radix);++            fmt = flags & BF_FTOA_FORMAT_MASK;+            bf_init(ctx, a1);+            if (fmt == BF_FTOA_FORMAT_FRAC) {+                if (is_dec || radix_bits != 0) {+                    if (bf_set(a1, a2))+                        goto fail1;+#ifdef USE_BF_DEC+                    if (is_dec) {+                        if (bfdec_round((bfdec_t *)a1, prec, (flags & BF_RND_MASK) | BF_FLAG_RADPNT_PREC) & BF_ST_MEM_ERROR)+                            goto fail1;+                        n = a1->expn;+                    } else+#endif+                    {+                        if (bf_round(a1, prec * radix_bits, (flags & BF_RND_MASK) | BF_FLAG_RADPNT_PREC) & BF_ST_MEM_ERROR)+                            goto fail1;+                        n = ceil_div(a1->expn, radix_bits);+                    }+                    if (flags & BF_FTOA_ADD_PREFIX) {+                        if (radix == 16)+                            dbuf_putstr(s, "0x");+                        else if (radix == 8)+                            dbuf_putstr(s, "0o");+                        else if (radix == 2)+                            dbuf_putstr(s, "0b");+                    }+                    if (a1->expn == BF_EXP_ZERO) {+                        dbuf_putstr(s, "0");+                        if (prec > 0) {+                            dbuf_putstr(s, ".");+                            for(i = 0; i < prec; i++) {+                                dbuf_putc(s, '0');+                            }+                        }+                    } else {+                        n_digits = prec + n;+                        if (n <= 0) {+                            /* 0.x */+                            dbuf_putstr(s, "0.");+                            for(i = 0; i < -n; i++) {+                                dbuf_putc(s, '0');+                            }+                            if (n_digits > 0) {+                                output_digits(s, a1, radix, n_digits, n_digits, is_dec);+                            }+                        } else {+                            output_digits(s, a1, radix, n_digits, n, is_dec);+                        }+                    }+                } else {+                    size_t pos, start;+                    bf_t a_s, *a = &a_s;++                    /* make a positive number */+                    a->tab = a2->tab;+                    a->len = a2->len;+                    a->expn = a2->expn;+                    a->sign = 0;+                    +                    /* one more digit for the rounding */+                    n = 1 + bf_mul_log2_radix(bf_max(a->expn, 0), radix, TRUE, TRUE);+                    n_digits = n + prec;+                    n1 = n;+                    if (bf_convert_to_radix(a1, &n1, a, radix, n_digits,+                                            flags & BF_RND_MASK, TRUE))+                        goto fail1;+                    start = s->size;+                    output_digits(s, a1, radix, n_digits, n, is_dec);+                    /* remove leading zeros because we allocated one more digit */+                    pos = start;+                    while ((pos + 1) < s->size && s->buf[pos] == '0' &&+                           s->buf[pos + 1] != '.')+                        pos++;+                    if (pos > start) {+                        memmove(s->buf + start, s->buf + pos, s->size - pos);+                        s->size -= (pos - start);+                    }+                }+            } else {+#ifdef USE_BF_DEC+                if (is_dec) {+                    if (bf_set(a1, a2))+                        goto fail1;+                    if (fmt == BF_FTOA_FORMAT_FIXED) {+                        n_digits = prec;+                        n_max = n_digits;+                        if (bfdec_round((bfdec_t *)a1, prec, (flags & BF_RND_MASK)) & BF_ST_MEM_ERROR)+                            goto fail1;+                    } else {+                        /* prec is ignored */+                        prec = n_digits = a1->len * LIMB_DIGITS;+                        /* remove the trailing zero digits */+                        while (n_digits > 1 &&+                               get_digit(a1->tab, a1->len, prec - n_digits) == 0) {+                            n_digits--;+                        }+                        n_max = n_digits + 4;+                    }+                    n = a1->expn;+                } else+#endif+                if (radix_bits != 0) {+                    if (bf_set(a1, a2))+                        goto fail1;+                    if (fmt == BF_FTOA_FORMAT_FIXED) {+                        slimb_t prec_bits;+                        n_digits = prec;+                        n_max = n_digits;+                        /* align to the radix point */+                        prec_bits = prec * radix_bits -+                            smod(-a1->expn, radix_bits);+                        if (bf_round(a1, prec_bits,+                                     (flags & BF_RND_MASK)) & BF_ST_MEM_ERROR)+                            goto fail1;+                    } else {+                        limb_t digit_mask;+                        slimb_t pos;+                        /* position of the digit before the most+                           significant digit in bits */+                        pos = a1->len * LIMB_BITS ++                            smod(-a1->expn, radix_bits);+                        n_digits = ceil_div(pos, radix_bits);+                        /* remove the trailing zero digits */+                        digit_mask = ((limb_t)1 << radix_bits) - 1;+                        while (n_digits > 1 &&+                               (get_bits(a1->tab, a1->len, pos - n_digits * radix_bits) & digit_mask) == 0) {+                            n_digits--;+                        }+                        n_max = n_digits + 4;+                    }+                    n = ceil_div(a1->expn, radix_bits);+                } else {+                    bf_t a_s, *a = &a_s;+                    +                    /* make a positive number */+                    a->tab = a2->tab;+                    a->len = a2->len;+                    a->expn = a2->expn;+                    a->sign = 0;+                    +                    if (fmt == BF_FTOA_FORMAT_FIXED) {+                        n_digits = prec;+                        n_max = n_digits;+                    } else {+                        slimb_t n_digits_max, n_digits_min;+                        +                        assert(prec != BF_PREC_INF);+                        n_digits = 1 + bf_mul_log2_radix(prec, radix, TRUE, TRUE);+                        /* max number of digits for non exponential+                           notation. The rational is to have the same rule+                           as JS i.e. n_max = 21 for 64 bit float in base 10. */+                        n_max = n_digits + 4;+                        if (fmt == BF_FTOA_FORMAT_FREE_MIN) {+                            bf_t b_s, *b = &b_s;+                            +                            /* find the minimum number of digits by+                               dichotomy. */+                            /* XXX: inefficient */+                            n_digits_max = n_digits;+                            n_digits_min = 1;+                            bf_init(ctx, b);+                            while (n_digits_min < n_digits_max) {+                                n_digits = (n_digits_min + n_digits_max) / 2;+                                if (bf_convert_to_radix(a1, &n, a, radix, n_digits,+                                                        flags & BF_RND_MASK, FALSE)) {+                                    bf_delete(b);+                                    goto fail1;+                                }+                                /* convert back to a number and compare */+                                ret = bf_mul_pow_radix(b, a1, radix, n - n_digits,+                                                       prec,+                                                       (flags & ~BF_RND_MASK) |+                                                       BF_RNDN);+                                if (ret & BF_ST_MEM_ERROR) {+                                    bf_delete(b);+                                    goto fail1;+                                }+                                if (bf_cmpu(b, a) == 0) {+                                    n_digits_max = n_digits;+                                } else {+                                    n_digits_min = n_digits + 1;+                                }+                            }+                            bf_delete(b);+                            n_digits = n_digits_max;+                        }+                    }+                    if (bf_convert_to_radix(a1, &n, a, radix, n_digits,+                                            flags & BF_RND_MASK, FALSE)) {+                    fail1:+                        bf_delete(a1);+                        goto fail;+                    }+                }+                if (a1->expn == BF_EXP_ZERO &&+                    fmt != BF_FTOA_FORMAT_FIXED &&+                    !(flags & BF_FTOA_FORCE_EXP)) {+                    /* just output zero */+                    dbuf_putstr(s, "0");+                } else {+                    if (flags & BF_FTOA_ADD_PREFIX) {+                        if (radix == 16)+                            dbuf_putstr(s, "0x");+                        else if (radix == 8)+                            dbuf_putstr(s, "0o");+                        else if (radix == 2)+                            dbuf_putstr(s, "0b");+                    }+                    if (a1->expn == BF_EXP_ZERO)+                        n = 1;+                    if ((flags & BF_FTOA_FORCE_EXP) ||+                        n <= -6 || n > n_max) {+                        const char *fmt;+                        /* exponential notation */+                        output_digits(s, a1, radix, n_digits, 1, is_dec);+                        if (radix_bits != 0 && radix <= 16) {+                            if (flags & BF_FTOA_JS_QUIRKS)+                                fmt = "p%+" PRId_LIMB;+                            else+                                fmt = "p%" PRId_LIMB;+                            dbuf_printf(s, fmt, (n - 1) * radix_bits);+                        } else {+                            if (flags & BF_FTOA_JS_QUIRKS)+                                fmt = "%c%+" PRId_LIMB;+                            else+                                fmt = "%c%" PRId_LIMB;+                            dbuf_printf(s, fmt,+                                        radix <= 10 ? 'e' : '@', n - 1);+                        }+                    } else if (n <= 0) {+                        /* 0.x */+                        dbuf_putstr(s, "0.");+                        for(i = 0; i < -n; i++) {+                            dbuf_putc(s, '0');+                        }+                        output_digits(s, a1, radix, n_digits, n_digits, is_dec);+                    } else {+                        if (n_digits <= n) {+                            /* no dot */+                            output_digits(s, a1, radix, n_digits, n_digits, is_dec);+                            for(i = 0; i < (n - n_digits); i++)+                                dbuf_putc(s, '0');+                        } else {+                            output_digits(s, a1, radix, n_digits, n, is_dec);+                        }+                    }+                }+            }+            bf_delete(a1);+        }+    }+    dbuf_putc(s, '\0');+    if (dbuf_error(s))+        goto fail;+    if (plen)+        *plen = s->size - 1;+    return (char *)s->buf;+ fail:+    bf_free(ctx, s->buf);+    if (plen)+        *plen = 0;+    return NULL;+}++char *bf_ftoa(size_t *plen, const bf_t *a, int radix, limb_t prec,+              bf_flags_t flags)+{+    return bf_ftoa_internal(plen, a, radix, prec, flags, FALSE);+}++/***************************************************************/+/* transcendental functions */++/* Note: the algorithm is from MPFR */+static void bf_const_log2_rec(bf_t *T, bf_t *P, bf_t *Q, limb_t n1,+                              limb_t n2, BOOL need_P)+{+    bf_context_t *s = T->ctx;+    if ((n2 - n1) == 1) {+        if (n1 == 0) {+            bf_set_ui(P, 3);+        } else {+            bf_set_ui(P, n1);+            P->sign = 1;+        }+        bf_set_ui(Q, 2 * n1 + 1);+        Q->expn += 2;+        bf_set(T, P);+    } else {+        limb_t m;+        bf_t T1_s, *T1 = &T1_s;+        bf_t P1_s, *P1 = &P1_s;+        bf_t Q1_s, *Q1 = &Q1_s;+        +        m = n1 + ((n2 - n1) >> 1);+        bf_const_log2_rec(T, P, Q, n1, m, TRUE);+        bf_init(s, T1);+        bf_init(s, P1);+        bf_init(s, Q1);+        bf_const_log2_rec(T1, P1, Q1, m, n2, need_P);+        bf_mul(T, T, Q1, BF_PREC_INF, BF_RNDZ);+        bf_mul(T1, T1, P, BF_PREC_INF, BF_RNDZ);+        bf_add(T, T, T1, BF_PREC_INF, BF_RNDZ);+        if (need_P)+            bf_mul(P, P, P1, BF_PREC_INF, BF_RNDZ);+        bf_mul(Q, Q, Q1, BF_PREC_INF, BF_RNDZ);+        bf_delete(T1);+        bf_delete(P1);+        bf_delete(Q1);+    }+}++/* compute log(2) with faithful rounding at precision 'prec' */+static void bf_const_log2_internal(bf_t *T, limb_t prec)+{+    limb_t w, N;+    bf_t P_s, *P = &P_s;+    bf_t Q_s, *Q = &Q_s;++    w = prec + 15;+    N = w / 3 + 1;+    bf_init(T->ctx, P);+    bf_init(T->ctx, Q);+    bf_const_log2_rec(T, P, Q, 0, N, FALSE);+    bf_div(T, T, Q, prec, BF_RNDN);+    bf_delete(P);+    bf_delete(Q);+}++/* PI constant */++#define CHUD_A 13591409+#define CHUD_B 545140134+#define CHUD_C 640320+#define CHUD_BITS_PER_TERM 47++static void chud_bs(bf_t *P, bf_t *Q, bf_t *G, int64_t a, int64_t b, int need_g,+                    limb_t prec)+{+    bf_context_t *s = P->ctx;+    int64_t c;++    if (a == (b - 1)) {+        bf_t T0, T1;+        +        bf_init(s, &T0);+        bf_init(s, &T1);+        bf_set_ui(G, 2 * b - 1);+        bf_mul_ui(G, G, 6 * b - 1, prec, BF_RNDN);+        bf_mul_ui(G, G, 6 * b - 5, prec, BF_RNDN);+        bf_set_ui(&T0, CHUD_B);+        bf_mul_ui(&T0, &T0, b, prec, BF_RNDN);+        bf_set_ui(&T1, CHUD_A);+        bf_add(&T0, &T0, &T1, prec, BF_RNDN);+        bf_mul(P, G, &T0, prec, BF_RNDN);+        P->sign = b & 1;++        bf_set_ui(Q, b);+        bf_mul_ui(Q, Q, b, prec, BF_RNDN);+        bf_mul_ui(Q, Q, b, prec, BF_RNDN);+        bf_mul_ui(Q, Q, (uint64_t)CHUD_C * CHUD_C * CHUD_C / 24, prec, BF_RNDN);+        bf_delete(&T0);+        bf_delete(&T1);+    } else {+        bf_t P2, Q2, G2;+        +        bf_init(s, &P2);+        bf_init(s, &Q2);+        bf_init(s, &G2);++        c = (a + b) / 2;+        chud_bs(P, Q, G, a, c, 1, prec);+        chud_bs(&P2, &Q2, &G2, c, b, need_g, prec);+        +        /* Q = Q1 * Q2 */+        /* G = G1 * G2 */+        /* P = P1 * Q2 + P2 * G1 */+        bf_mul(&P2, &P2, G, prec, BF_RNDN);+        if (!need_g)+            bf_set_ui(G, 0);+        bf_mul(P, P, &Q2, prec, BF_RNDN);+        bf_add(P, P, &P2, prec, BF_RNDN);+        bf_delete(&P2);++        bf_mul(Q, Q, &Q2, prec, BF_RNDN);+        bf_delete(&Q2);+        if (need_g)+            bf_mul(G, G, &G2, prec, BF_RNDN);+        bf_delete(&G2);+    }+}++/* compute Pi with faithful rounding at precision 'prec' using the+   Chudnovsky formula */+static void bf_const_pi_internal(bf_t *Q, limb_t prec)+{+    bf_context_t *s = Q->ctx;+    int64_t n, prec1;+    bf_t P, G;++    /* number of serie terms */+    n = prec / CHUD_BITS_PER_TERM + 1;+    /* XXX: precision analysis */+    prec1 = prec + 32;++    bf_init(s, &P);+    bf_init(s, &G);++    chud_bs(&P, Q, &G, 0, n, 0, BF_PREC_INF);+    +    bf_mul_ui(&G, Q, CHUD_A, prec1, BF_RNDN);+    bf_add(&P, &G, &P, prec1, BF_RNDN);+    bf_div(Q, Q, &P, prec1, BF_RNDF);+ +    bf_set_ui(&P, CHUD_C);+    bf_sqrt(&G, &P, prec1, BF_RNDF);+    bf_mul_ui(&G, &G, (uint64_t)CHUD_C / 12, prec1, BF_RNDF);+    bf_mul(Q, Q, &G, prec, BF_RNDN);+    bf_delete(&P);+    bf_delete(&G);+}++static int bf_const_get(bf_t *T, limb_t prec, bf_flags_t flags,+                        BFConstCache *c,+                        void (*func)(bf_t *res, limb_t prec), int sign)+{+    limb_t ziv_extra_bits, prec1;++    ziv_extra_bits = 32;+    for(;;) {+        prec1 = prec + ziv_extra_bits;+        if (c->prec < prec1) {+            if (c->val.len == 0)+                bf_init(T->ctx, &c->val);+            func(&c->val, prec1);+            c->prec = prec1;+        } else {+            prec1 = c->prec;+        }+        bf_set(T, &c->val);+        T->sign = sign;+        if (!bf_can_round(T, prec, flags & BF_RND_MASK, prec1)) {+            /* and more precision and retry */+            ziv_extra_bits = ziv_extra_bits  + (ziv_extra_bits / 2);+        } else {+            break;+        }+    }+    return bf_round(T, prec, flags);+}++static void bf_const_free(BFConstCache *c)+{+    bf_delete(&c->val);+    memset(c, 0, sizeof(*c));+}++int bf_const_log2(bf_t *T, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = T->ctx;+    return bf_const_get(T, prec, flags, &s->log2_cache, bf_const_log2_internal, 0);+}++/* return rounded pi * (1 - 2 * sign) */+static int bf_const_pi_signed(bf_t *T, int sign, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = T->ctx;+    return bf_const_get(T, prec, flags, &s->pi_cache, bf_const_pi_internal,+                        sign);+}++int bf_const_pi(bf_t *T, limb_t prec, bf_flags_t flags)+{+    return bf_const_pi_signed(T, 0, prec, flags);+}++void bf_clear_cache(bf_context_t *s)+{+#ifdef USE_FFT_MUL+    fft_clear_cache(s);+#endif+    bf_const_free(&s->log2_cache);+    bf_const_free(&s->pi_cache);+}++/* ZivFunc should compute the result 'r' with faithful rounding at+   precision 'prec'. For efficiency purposes, the final bf_round()+   does not need to be done in the function. */+typedef int ZivFunc(bf_t *r, const bf_t *a, limb_t prec, void *opaque);++static int bf_ziv_rounding(bf_t *r, const bf_t *a,+                           limb_t prec, bf_flags_t flags,+                           ZivFunc *f, void *opaque)+{+    int rnd_mode, ret;+    slimb_t prec1, ziv_extra_bits;+    +    rnd_mode = flags & BF_RND_MASK;+    if (rnd_mode == BF_RNDF) {+        /* no need to iterate */+        f(r, a, prec, opaque);+        ret = 0;+    } else {+        ziv_extra_bits = 32;+        for(;;) {+            prec1 = prec + ziv_extra_bits;+            ret = f(r, a, prec1, opaque);+            if (ret & (BF_ST_OVERFLOW | BF_ST_UNDERFLOW | BF_ST_MEM_ERROR)) {+                /* overflow or underflow should never happen because+                   it indicates the rounding cannot be done correctly,+                   but we do not catch all the cases */+                return ret;+            }+            /* if the result is exact, we can stop */+            if (!(ret & BF_ST_INEXACT)) {+                ret = 0;+                break;+            }+            if (bf_can_round(r, prec, rnd_mode, prec1)) {+                ret = BF_ST_INEXACT;+                break;+            }+            ziv_extra_bits = ziv_extra_bits * 2;+            //            printf("ziv_extra_bits=%" PRId64 "\n", (int64_t)ziv_extra_bits);+        }+    }+    if (r->len == 0)+        return ret;+    else+        return __bf_round(r, prec, flags, r->len, ret);+}++/* add (1 - 2*e_sign) * 2^e */+static int bf_add_epsilon(bf_t *r, const bf_t *a, slimb_t e, int e_sign,+                          limb_t prec, int flags)+{+    bf_t T_s, *T = &T_s;+    int ret;+    /* small argument case: result = 1 + epsilon * sign(x) */+    bf_init(a->ctx, T);+    bf_set_ui(T, 1);+    T->sign = e_sign;+    T->expn += e;+    ret = bf_add(r, r, T, prec, flags);+    bf_delete(T);+    return ret;+}++/* Compute the exponential using faithful rounding at precision 'prec'.+   Note: the algorithm is from MPFR */+static int bf_exp_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    slimb_t n, K, l, i, prec1;+    +    assert(r != a);++    /* argument reduction:+       T = a - n*log(2) with 0 <= T < log(2) and n integer.+    */+    bf_init(s, T);+    if (a->expn <= -1) {+        /* 0 <= abs(a) <= 0.5 */+        if (a->sign)+            n = -1;+        else+            n = 0;+    } else {+        bf_const_log2(T, LIMB_BITS, BF_RNDZ);+        bf_div(T, a, T, LIMB_BITS, BF_RNDD);+        bf_get_limb(&n, T, 0);+    }++    K = bf_isqrt((prec + 1) / 2);+    l = (prec - 1) / K + 1;+    /* XXX: precision analysis ? */+    prec1 = prec + (K + 2 * l + 18) + K + 8;+    if (a->expn > 0)+        prec1 += a->expn;+    //    printf("n=%ld K=%ld prec1=%ld\n", n, K, prec1);++    bf_const_log2(T, prec1, BF_RNDF);+    bf_mul_si(T, T, n, prec1, BF_RNDN);+    bf_sub(T, a, T, prec1, BF_RNDN);++    /* reduce the range of T */+    bf_mul_2exp(T, -K, BF_PREC_INF, BF_RNDZ);+    +    /* Taylor expansion around zero :+     1 + x + x^2/2 + ... + x^n/n! +     = (1 + x * (1 + x/2 * (1 + ... (x/n))))+    */+    {+        bf_t U_s, *U = &U_s;+        +        bf_init(s, U);+        bf_set_ui(r, 1);+        for(i = l ; i >= 1; i--) {+            bf_set_ui(U, i);+            bf_div(U, T, U, prec1, BF_RNDN);+            bf_mul(r, r, U, prec1, BF_RNDN);+            bf_add_si(r, r, 1, prec1, BF_RNDN);+        }+        bf_delete(U);+    }+    bf_delete(T);+    +    /* undo the range reduction */+    for(i = 0; i < K; i++) {+        bf_mul(r, r, r, prec1, BF_RNDN | BF_FLAG_EXT_EXP);+    }++    /* undo the argument reduction */+    bf_mul_2exp(r, n, BF_PREC_INF, BF_RNDZ | BF_FLAG_EXT_EXP);++    return BF_ST_INEXACT;+}++/* crude overflow and underflow tests for exp(a). a_low <= a <= a_high */+static int check_exp_underflow_overflow(bf_context_t *s, bf_t *r,+                                        const bf_t *a_low, const bf_t *a_high,+                                        limb_t prec, bf_flags_t flags)+{+    bf_t T_s, *T = &T_s;+    bf_t log2_s, *log2 = &log2_s;+    slimb_t e_min, e_max;+    +    if (a_high->expn <= 0)+        return 0;++    e_max = (limb_t)1 << (bf_get_exp_bits(flags) - 1);+    e_min = -e_max + 3;+    if (flags & BF_FLAG_SUBNORMAL)+        e_min -= (prec - 1);+    +    bf_init(s, T);+    bf_init(s, log2);+    bf_const_log2(log2, LIMB_BITS, BF_RNDU);+    bf_mul_ui(T, log2, e_max, LIMB_BITS, BF_RNDU);+    /* a_low > e_max * log(2) implies exp(a) > e_max */+    if (bf_cmp_lt(T, a_low) > 0) {+        /* overflow */+        bf_delete(T);+        bf_delete(log2);+        return bf_set_overflow(r, 0, prec, flags);+    }+    /* a_high < (e_min - 2) * log(2) implies exp(a) < (e_min - 2) */+    bf_const_log2(log2, LIMB_BITS, BF_RNDD);+    bf_mul_si(T, log2, e_min - 2, LIMB_BITS, BF_RNDD);+    if (bf_cmp_lt(a_high, T)) {+        int rnd_mode = flags & BF_RND_MASK;+        +        /* underflow */+        bf_delete(T);+        bf_delete(log2);+        if (rnd_mode == BF_RNDU) {+            /* set the smallest value */+            bf_set_ui(r, 1);+            r->expn = e_min;+        } else {+            bf_set_zero(r, 0);+        }+        return BF_ST_UNDERFLOW | BF_ST_INEXACT;+    }+    bf_delete(log2);+    bf_delete(T);+    return 0;+}++int bf_exp(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    int ret;+    assert(r != a);+    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+        } else if (a->expn == BF_EXP_INF) {+            if (a->sign)+                bf_set_zero(r, 0);+            else+                bf_set_inf(r, 0);+        } else {+            bf_set_ui(r, 1);+        }+        return 0;+    }++    ret = check_exp_underflow_overflow(s, r, a, a, prec, flags);+    if (ret)+        return ret;+    if (a->expn < 0 && (-a->expn) >= (prec + 2)) { +        /* small argument case: result = 1 + epsilon * sign(x) */+        bf_set_ui(r, 1);+        return bf_add_epsilon(r, r, -(prec + 2), a->sign, prec, flags);+    }+                         +    return bf_ziv_rounding(r, a, prec, flags, bf_exp_internal, NULL);+}++static int bf_log_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    bf_t U_s, *U = &U_s;+    bf_t V_s, *V = &V_s;+    slimb_t n, prec1, l, i, K;+    +    assert(r != a);++    bf_init(s, T);+    /* argument reduction 1 */+    /* T=a*2^n with 2/3 <= T <= 4/3 */+    {+        bf_t U_s, *U = &U_s;+        bf_set(T, a);+        n = T->expn;+        T->expn = 0;+        /* U= ~ 2/3 */+        bf_init(s, U);+        bf_set_ui(U, 0xaaaaaaaa); +        U->expn = 0;+        if (bf_cmp_lt(T, U)) {+            T->expn++;+            n--;+        }+        bf_delete(U);+    }+    //    printf("n=%ld\n", n);+    //    bf_print_str("T", T);++    /* XXX: precision analysis */+    /* number of iterations for argument reduction 2 */+    K = bf_isqrt((prec + 1) / 2); +    /* order of Taylor expansion */+    l = prec / (2 * K) + 1; +    /* precision of the intermediate computations */+    prec1 = prec + K + 2 * l + 32;++    bf_init(s, U);+    bf_init(s, V);+    +    /* Note: cancellation occurs here, so we use more precision (XXX:+       reduce the precision by computing the exact cancellation) */+    bf_add_si(T, T, -1, BF_PREC_INF, BF_RNDN); ++    /* argument reduction 2 */+    for(i = 0; i < K; i++) {+        /* T = T / (1 + sqrt(1 + T)) */+        bf_add_si(U, T, 1, prec1, BF_RNDN);+        bf_sqrt(V, U, prec1, BF_RNDF);+        bf_add_si(U, V, 1, prec1, BF_RNDN);+        bf_div(T, T, U, prec1, BF_RNDN);+    }++    {+        bf_t Y_s, *Y = &Y_s;+        bf_t Y2_s, *Y2 = &Y2_s;+        bf_init(s, Y);+        bf_init(s, Y2);++        /* compute ln(1+x) = ln((1+y)/(1-y)) with y=x/(2+x)+           = y + y^3/3 + ... + y^(2*l + 1) / (2*l+1) +           with Y=Y^2+           = y*(1+Y/3+Y^2/5+...) = y*(1+Y*(1/3+Y*(1/5 + ...)))+        */+        bf_add_si(Y, T, 2, prec1, BF_RNDN);+        bf_div(Y, T, Y, prec1, BF_RNDN);++        bf_mul(Y2, Y, Y, prec1, BF_RNDN);+        bf_set_ui(r, 0);+        for(i = l; i >= 1; i--) {+            bf_set_ui(U, 1);+            bf_set_ui(V, 2 * i + 1);+            bf_div(U, U, V, prec1, BF_RNDN);+            bf_add(r, r, U, prec1, BF_RNDN);+            bf_mul(r, r, Y2, prec1, BF_RNDN);+        }+        bf_add_si(r, r, 1, prec1, BF_RNDN);+        bf_mul(r, r, Y, prec1, BF_RNDN);+        bf_delete(Y);+        bf_delete(Y2);+    }+    bf_delete(V);+    bf_delete(U);++    /* multiplication by 2 for the Taylor expansion and undo the+       argument reduction 2*/+    bf_mul_2exp(r, K + 1, BF_PREC_INF, BF_RNDZ);+    +    /* undo the argument reduction 1 */+    bf_const_log2(T, prec1, BF_RNDF);+    bf_mul_si(T, T, n, prec1, BF_RNDN);+    bf_add(r, r, T, prec1, BF_RNDN);+    +    bf_delete(T);+    return BF_ST_INEXACT;+}++int bf_log(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    +    assert(r != a);+    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            if (a->sign) {+                bf_set_nan(r);+                return BF_ST_INVALID_OP;+            } else {+                bf_set_inf(r, 0);+                return 0;+            }+        } else {+            bf_set_inf(r, 1);+            return 0;+        }+    }+    if (a->sign) {+        bf_set_nan(r);+        return BF_ST_INVALID_OP;+    }+    bf_init(s, T);+    bf_set_ui(T, 1);+    if (bf_cmp_eq(a, T)) {+        bf_set_zero(r, 0);+        bf_delete(T);+        return 0;+    }+    bf_delete(T);++    return bf_ziv_rounding(r, a, prec, flags, bf_log_internal, NULL);+}++/* x and y finite and x > 0 */+static int bf_pow_generic(bf_t *r, const bf_t *x, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    const bf_t *y = opaque;+    bf_t T_s, *T = &T_s;+    limb_t prec1;++    bf_init(s, T);+    /* XXX: proof for the added precision */+    prec1 = prec + 32;+    bf_log(T, x, prec1, BF_RNDF | BF_FLAG_EXT_EXP);+    bf_mul(T, T, y, prec1, BF_RNDF | BF_FLAG_EXT_EXP);+    if (bf_is_nan(T))+        bf_set_nan(r);+    else+        bf_exp_internal(r, T, prec1, NULL); /* no overflow/underlow test needed */+    bf_delete(T);+    return BF_ST_INEXACT;+}++/* x and y finite, x > 0, y integer and y fits on one limb */+static int bf_pow_int(bf_t *r, const bf_t *x, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    const bf_t *y = opaque;+    bf_t T_s, *T = &T_s;+    limb_t prec1;+    int ret;+    slimb_t y1;+    +    bf_get_limb(&y1, y, 0);+    if (y1 < 0)+        y1 = -y1;+    /* XXX: proof for the added precision */+    prec1 = prec + ceil_log2(y1) * 2 + 8;+    ret = bf_pow_ui(r, x, y1 < 0 ? -y1 : y1, prec1, BF_RNDN | BF_FLAG_EXT_EXP);+    if (y->sign) {+        bf_init(s, T);+        bf_set_ui(T, 1);+        ret |= bf_div(r, T, r, prec1, BF_RNDN | BF_FLAG_EXT_EXP);+        bf_delete(T);+    }+    return ret;+}++/* x must be a finite non zero float. Return TRUE if there is a+   floating point number r such as x=r^(2^n) and return this floating+   point number 'r'. Otherwise return FALSE and r is undefined. */+static BOOL check_exact_power2n(bf_t *r, const bf_t *x, slimb_t n)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    slimb_t e, i, er;+    limb_t v;+    +    /* x = m*2^e with m odd integer */+    e = bf_get_exp_min(x);+    /* fast check on the exponent */+    if (n > (LIMB_BITS - 1)) {+        if (e != 0)+            return FALSE;+        er = 0;+    } else {+        if ((e & (((limb_t)1 << n) - 1)) != 0)+            return FALSE;+        er = e >> n;+    }+    /* every perfect odd square = 1 modulo 8 */+    v = get_bits(x->tab, x->len, x->len * LIMB_BITS - x->expn + e);+    if ((v & 7) != 1)+        return FALSE;++    bf_init(s, T);+    bf_set(T, x);+    T->expn -= e;+    for(i = 0; i < n; i++) {+        if (i != 0)+            bf_set(T, r);+        if (bf_sqrtrem(r, NULL, T) != 0)+            return FALSE;+    }+    r->expn += er;+    return TRUE;+}++/* prec = BF_PREC_INF is accepted for x and y integers and y >= 0 */+int bf_pow(bf_t *r, const bf_t *x, const bf_t *y, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    bf_t ytmp_s;+    BOOL y_is_int, y_is_odd;+    int r_sign, ret, rnd_mode;+    slimb_t y_emin;+    +    if (x->len == 0 || y->len == 0) {+        if (y->expn == BF_EXP_ZERO) {+            /* pow(x, 0) = 1 */+            bf_set_ui(r, 1);+        } else if (x->expn == BF_EXP_NAN) {+            bf_set_nan(r);+        } else {+            int cmp_x_abs_1;+            bf_set_ui(r, 1);+            cmp_x_abs_1 = bf_cmpu(x, r);+            if (cmp_x_abs_1 == 0 && (flags & BF_POW_JS_QUIRKS) &&+                (y->expn >= BF_EXP_INF)) {+                bf_set_nan(r);+            } else if (cmp_x_abs_1 == 0 &&+                       (!x->sign || y->expn != BF_EXP_NAN)) {+                /* pow(1, y) = 1 even if y = NaN */+                /* pow(-1, +/-inf) = 1 */+            } else if (y->expn == BF_EXP_NAN) {+                bf_set_nan(r);+            } else if (y->expn == BF_EXP_INF) {+                if (y->sign == (cmp_x_abs_1 > 0)) {+                    bf_set_zero(r, 0);+                } else {+                    bf_set_inf(r, 0);+                }+            } else {+                y_emin = bf_get_exp_min(y);+                y_is_odd = (y_emin == 0);+                if (y->sign == (x->expn == BF_EXP_ZERO)) {+                    bf_set_inf(r, y_is_odd & x->sign);+                    if (y->sign) {+                        /* pow(0, y) with y < 0 */+                        return BF_ST_DIVIDE_ZERO;+                    }+                } else {+                    bf_set_zero(r, y_is_odd & x->sign);+                }+            }+        }+        return 0;+    }+    bf_init(s, T);+    bf_set(T, x);+    y_emin = bf_get_exp_min(y);+    y_is_int = (y_emin >= 0);+    rnd_mode = flags & BF_RND_MASK;+    if (x->sign) {+        if (!y_is_int) {+            bf_set_nan(r);+            bf_delete(T);+            return BF_ST_INVALID_OP;+        }+        y_is_odd = (y_emin == 0);+        r_sign = y_is_odd;+        /* change the directed rounding mode if the sign of the result+           is changed */+        if (r_sign && (rnd_mode == BF_RNDD || rnd_mode == BF_RNDU))+            flags ^= 1;+        bf_neg(T);+    } else {+        r_sign = 0;+    }++    bf_set_ui(r, 1);+    if (bf_cmp_eq(T, r)) {+        /* abs(x) = 1: nothing more to do */+        ret = 0;+    } else {+        /* check the overflow/underflow cases */+        {+            bf_t al_s, *al = &al_s;+            bf_t ah_s, *ah = &ah_s;+            limb_t precl = LIMB_BITS;+            +            bf_init(s, al);+            bf_init(s, ah);+            /* compute bounds of log(abs(x)) * y with a low precision */+            /* XXX: compute bf_log() once */+            /* XXX: add a fast test before this slow test */+            bf_log(al, T, precl, BF_RNDD);+            bf_log(ah, T, precl, BF_RNDU);+            bf_mul(al, al, y, precl, BF_RNDD ^ y->sign);+            bf_mul(ah, ah, y, precl, BF_RNDU ^ y->sign);+            ret = check_exp_underflow_overflow(s, r, al, ah, prec, flags);+            bf_delete(al);+            bf_delete(ah);+            if (ret)+                goto done;+        }+        +        if (y_is_int) {+            slimb_t T_bits, e;+        int_pow:+            T_bits = T->expn - bf_get_exp_min(T);+            if (T_bits == 1) {+                /* pow(2^b, y) = 2^(b*y) */+                bf_mul_si(T, y, T->expn - 1, LIMB_BITS, BF_RNDZ);+                bf_get_limb(&e, T, 0);+                bf_set_ui(r, 1);+                ret = bf_mul_2exp(r, e, prec, flags);+            } else if (prec == BF_PREC_INF) {+                slimb_t y1;+                /* specific case for infinite precision (integer case) */+                bf_get_limb(&y1, y, 0);+                assert(!y->sign);+                /* x must be an integer, so abs(x) >= 2 */+                if (y1 >= ((slimb_t)1 << BF_EXP_BITS_MAX)) {+                    bf_delete(T);+                    return bf_set_overflow(r, 0, BF_PREC_INF, flags);+                }+                ret = bf_pow_ui(r, T, y1, BF_PREC_INF, BF_RNDZ);+            } else {+                if (y->expn <= 31) {+                    /* small enough power: use exponentiation in all cases */+                } else if (y->sign) {+                    /* cannot be exact */+                    goto general_case;+                } else {+                    if (rnd_mode == BF_RNDF)+                        goto general_case; /* no need to track exact results */+                    /* see if the result has a chance to be exact:+                       if x=a*2^b (a odd), x^y=a^y*2^(b*y)+                       x^y needs a precision of at least floor_log2(a)*y bits+                    */+                    bf_mul_si(r, y, T_bits - 1, LIMB_BITS, BF_RNDZ);+                    bf_get_limb(&e, r, 0);+                    if (prec < e)+                        goto general_case;+                }+                ret = bf_ziv_rounding(r, T, prec, flags, bf_pow_int, (void *)y);+            }+        } else {+            if (rnd_mode != BF_RNDF) {+                bf_t *y1;+                if (y_emin < 0 && check_exact_power2n(r, T, -y_emin)) {+                    /* the problem is reduced to a power to an integer */+#if 0+                    printf("\nn=%" PRId64 "\n", -(int64_t)y_emin);+                    bf_print_str("T", T);+                    bf_print_str("r", r);+#endif+                    bf_set(T, r);+                    y1 = &ytmp_s;+                    y1->tab = y->tab;+                    y1->len = y->len;+                    y1->sign = y->sign;+                    y1->expn = y->expn - y_emin;+                    y = y1;+                    goto int_pow;+                }+            }+        general_case:+            ret = bf_ziv_rounding(r, T, prec, flags, bf_pow_generic, (void *)y);+        }+    }+ done:+    bf_delete(T);+    r->sign = r_sign;+    return ret;+}++/* compute sqrt(-2*x-x^2) to get |sin(x)| from cos(x) - 1. */+static void bf_sqrt_sin(bf_t *r, const bf_t *x, limb_t prec1)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    bf_init(s, T);+    bf_set(T, x);+    bf_mul(r, T, T, prec1, BF_RNDN);+    bf_mul_2exp(T, 1, BF_PREC_INF, BF_RNDZ);+    bf_add(T, T, r, prec1, BF_RNDN);+    bf_neg(T);+    bf_sqrt(r, T, prec1, BF_RNDF);+    bf_delete(T);+}++static int bf_sincos(bf_t *s, bf_t *c, const bf_t *a, limb_t prec)+{+    bf_context_t *s1 = a->ctx;+    bf_t T_s, *T = &T_s;+    bf_t U_s, *U = &U_s;+    bf_t r_s, *r = &r_s;+    slimb_t K, prec1, i, l, mod, prec2;+    int is_neg;+    +    assert(c != a && s != a);++    bf_init(s1, T);+    bf_init(s1, U);+    bf_init(s1, r);+    +    /* XXX: precision analysis */+    K = bf_isqrt(prec / 2);+    l = prec / (2 * K) + 1;+    prec1 = prec + 2 * K + l + 8;+    +    /* after the modulo reduction, -pi/4 <= T <= pi/4 */+    if (a->expn <= -1) {+        /* abs(a) <= 0.25: no modulo reduction needed */+        bf_set(T, a);+        mod = 0;+    } else {+        slimb_t cancel;+        cancel = 0;+        for(;;) {+            prec2 = prec1 + a->expn + cancel;+            bf_const_pi(U, prec2, BF_RNDF);+            bf_mul_2exp(U, -1, BF_PREC_INF, BF_RNDZ);+            bf_remquo(&mod, T, a, U, prec2, BF_RNDN, BF_RNDN);+            //            printf("T.expn=%ld prec2=%ld\n", T->expn, prec2);+            if (mod == 0 || (T->expn != BF_EXP_ZERO &&+                             (T->expn + prec2) >= (prec1 - 1)))+                break;+            /* increase the number of bits until the precision is good enough */+            cancel = bf_max(-T->expn, (cancel + 1) * 3 / 2);+        }+        mod &= 3;+    }+    +    is_neg = T->sign;+        +    /* compute cosm1(x) = cos(x) - 1 */+    bf_mul(T, T, T, prec1, BF_RNDN);+    bf_mul_2exp(T, -2 * K, BF_PREC_INF, BF_RNDZ);+    +    /* Taylor expansion:+       -x^2/2 + x^4/4! - x^6/6! + ...+    */+    bf_set_ui(r, 1);+    for(i = l ; i >= 1; i--) {+        bf_set_ui(U, 2 * i - 1);+        bf_mul_ui(U, U, 2 * i, BF_PREC_INF, BF_RNDZ);+        bf_div(U, T, U, prec1, BF_RNDN);+        bf_mul(r, r, U, prec1, BF_RNDN);+        bf_neg(r);+        if (i != 1)+            bf_add_si(r, r, 1, prec1, BF_RNDN);+    }+    bf_delete(U);++    /* undo argument reduction:+       cosm1(2*x)= 2*(2*cosm1(x)+cosm1(x)^2)+    */+    for(i = 0; i < K; i++) {+        bf_mul(T, r, r, prec1, BF_RNDN);+        bf_mul_2exp(r, 1, BF_PREC_INF, BF_RNDZ);+        bf_add(r, r, T, prec1, BF_RNDN);+        bf_mul_2exp(r, 1, BF_PREC_INF, BF_RNDZ);+    }+    bf_delete(T);++    if (c) {+        if ((mod & 1) == 0) {+            bf_add_si(c, r, 1, prec1, BF_RNDN);+        } else {+            bf_sqrt_sin(c, r, prec1);+            c->sign = is_neg ^ 1;+        }+        c->sign ^= mod >> 1;+    }+    if (s) {+        if ((mod & 1) == 0) {+            bf_sqrt_sin(s, r, prec1);+            s->sign = is_neg;+        } else {+            bf_add_si(s, r, 1, prec1, BF_RNDN);+        }+        s->sign ^= mod >> 1;+    }+    bf_delete(r);+    return BF_ST_INEXACT;+}++static int bf_cos_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    return bf_sincos(NULL, r, a, prec);+}++int bf_cos(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set_ui(r, 1);+            return 0;+        }+    }++    /* small argument case: result = 1+r(x) with r(x) = -x^2/2 ++       O(X^4). We assume r(x) < 2^(2*EXP(x) - 1). */+    if (a->expn < 0) {+        slimb_t e;+        e = 2 * a->expn - 1;+        if (e < -(prec + 2)) {+            bf_set_ui(r, 1);+            return bf_add_epsilon(r, r, e, 1, prec, flags);+        }+    }+    +    return bf_ziv_rounding(r, a, prec, flags, bf_cos_internal, NULL);+}++static int bf_sin_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    return bf_sincos(r, NULL, a, prec);+}++int bf_sin(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set_zero(r, a->sign);+            return 0;+        }+    }++    /* small argument case: result = x+r(x) with r(x) = -x^3/6 ++       O(X^5). We assume r(x) < 2^(3*EXP(x) - 2). */+    if (a->expn < 0) {+        slimb_t e;+        e = sat_add(2 * a->expn, a->expn - 2);+        if (e < a->expn - bf_max(prec + 2, a->len * LIMB_BITS + 2)) {+            bf_set(r, a);+            return bf_add_epsilon(r, r, e, 1 - a->sign, prec, flags);+        }+    }++    return bf_ziv_rounding(r, a, prec, flags, bf_sin_internal, NULL);+}++static int bf_tan_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    limb_t prec1;+    +    /* XXX: precision analysis */+    prec1 = prec + 8;+    bf_init(s, T);+    bf_sincos(r, T, a, prec1);+    bf_div(r, r, T, prec1, BF_RNDF);+    bf_delete(T);+    return BF_ST_INEXACT;+}++int bf_tan(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    assert(r != a);+    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set_zero(r, a->sign);+            return 0;+        }+    }++    /* small argument case: result = x+r(x) with r(x) = x^3/3 ++       O(X^5). We assume r(x) < 2^(3*EXP(x) - 1). */+    if (a->expn < 0) {+        slimb_t e;+        e = sat_add(2 * a->expn, a->expn - 1);+        if (e < a->expn - bf_max(prec + 2, a->len * LIMB_BITS + 2)) {+            bf_set(r, a);+            return bf_add_epsilon(r, r, e, a->sign, prec, flags);+        }+    }+            +    return bf_ziv_rounding(r, a, prec, flags, bf_tan_internal, NULL);+}++/* if add_pi2 is true, add pi/2 to the result (used for acos(x) to+   avoid cancellation) */+static int bf_atan_internal(bf_t *r, const bf_t *a, limb_t prec,+                            void *opaque)+{+    bf_context_t *s = r->ctx;+    BOOL add_pi2 = (BOOL)(intptr_t)opaque;+    bf_t T_s, *T = &T_s;+    bf_t U_s, *U = &U_s;+    bf_t V_s, *V = &V_s;+    bf_t X2_s, *X2 = &X2_s;+    int cmp_1;+    slimb_t prec1, i, K, l;+    +    /* XXX: precision analysis */+    K = bf_isqrt((prec + 1) / 2);+    l = prec / (2 * K) + 1;+    prec1 = prec + K + 2 * l + 32;+    //    printf("prec=%d K=%d l=%d prec1=%d\n", (int)prec, (int)K, (int)l, (int)prec1);+    +    bf_init(s, T);+    cmp_1 = (a->expn >= 1); /* a >= 1 */+    if (cmp_1) {+        bf_set_ui(T, 1);+        bf_div(T, T, a, prec1, BF_RNDN);+    } else {+        bf_set(T, a);+    }++    /* abs(T) <= 1 */++    /* argument reduction */++    bf_init(s, U);+    bf_init(s, V);+    bf_init(s, X2);+    for(i = 0; i < K; i++) {+        /* T = T / (1 + sqrt(1 + T^2)) */+        bf_mul(U, T, T, prec1, BF_RNDN);+        bf_add_si(U, U, 1, prec1, BF_RNDN);+        bf_sqrt(V, U, prec1, BF_RNDN);+        bf_add_si(V, V, 1, prec1, BF_RNDN);+        bf_div(T, T, V, prec1, BF_RNDN);+    }++    /* Taylor series: +       x - x^3/3 + ... + (-1)^ l * y^(2*l + 1) / (2*l+1) +    */+    bf_mul(X2, T, T, prec1, BF_RNDN);+    bf_set_ui(r, 0);+    for(i = l; i >= 1; i--) {+        bf_set_si(U, 1);+        bf_set_ui(V, 2 * i + 1);+        bf_div(U, U, V, prec1, BF_RNDN);+        bf_neg(r);+        bf_add(r, r, U, prec1, BF_RNDN);+        bf_mul(r, r, X2, prec1, BF_RNDN);+    }+    bf_neg(r);+    bf_add_si(r, r, 1, prec1, BF_RNDN);+    bf_mul(r, r, T, prec1, BF_RNDN);++    /* undo the argument reduction */+    bf_mul_2exp(r, K, BF_PREC_INF, BF_RNDZ);+    +    bf_delete(U);+    bf_delete(V);+    bf_delete(X2);++    i = add_pi2;+    if (cmp_1 > 0) {+        /* undo the inversion : r = sign(a)*PI/2 - r */+        bf_neg(r);+        i += 1 - 2 * a->sign;+    }+    /* add i*(pi/2) with -1 <= i <= 2 */+    if (i != 0) {+        bf_const_pi(T, prec1, BF_RNDF);+        if (i != 2)+            bf_mul_2exp(T, -1, BF_PREC_INF, BF_RNDZ);+        T->sign = (i < 0);+        bf_add(r, T, r, prec1, BF_RNDN);+    }+    +    bf_delete(T);+    return BF_ST_INEXACT;+}++int bf_atan(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    int res;+    +    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF)  {+            /* -PI/2 or PI/2 */+            bf_const_pi_signed(r, a->sign, prec, flags);+            bf_mul_2exp(r, -1, BF_PREC_INF, BF_RNDZ);+            return BF_ST_INEXACT;+        } else {+            bf_set_zero(r, a->sign);+            return 0;+        }+    }+    +    bf_init(s, T);+    bf_set_ui(T, 1);+    res = bf_cmpu(a, T);+    bf_delete(T);+    if (res == 0) {+        /* short cut: abs(a) == 1 -> +/-pi/4 */+        bf_const_pi_signed(r, a->sign, prec, flags);+        bf_mul_2exp(r, -2, BF_PREC_INF, BF_RNDZ);+        return BF_ST_INEXACT;+    }++    /* small argument case: result = x+r(x) with r(x) = -x^3/3 ++       O(X^5). We assume r(x) < 2^(3*EXP(x) - 1). */+    if (a->expn < 0) {+        slimb_t e;+        e = sat_add(2 * a->expn, a->expn - 1);+        if (e < a->expn - bf_max(prec + 2, a->len * LIMB_BITS + 2)) {+            bf_set(r, a);+            return bf_add_epsilon(r, r, e, 1 - a->sign, prec, flags);+        }+    }+    +    return bf_ziv_rounding(r, a, prec, flags, bf_atan_internal, (void *)FALSE);+}++static int bf_atan2_internal(bf_t *r, const bf_t *y, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    const bf_t *x = opaque;+    bf_t T_s, *T = &T_s;+    limb_t prec1;+    int ret;+    +    if (y->expn == BF_EXP_NAN || x->expn == BF_EXP_NAN) {+        bf_set_nan(r);+        return 0;+    }++    /* compute atan(y/x) assumming inf/inf = 1 and 0/0 = 0 */+    bf_init(s, T);+    prec1 = prec + 32;+    if (y->expn == BF_EXP_INF && x->expn == BF_EXP_INF) {+        bf_set_ui(T, 1);+        T->sign = y->sign ^ x->sign;+    } else if (y->expn == BF_EXP_ZERO && x->expn == BF_EXP_ZERO) {+        bf_set_zero(T, y->sign ^ x->sign);+    } else {+        bf_div(T, y, x, prec1, BF_RNDF);+    }+    ret = bf_atan(r, T, prec1, BF_RNDF);++    if (x->sign) {+        /* if x < 0 (it includes -0), return sign(y)*pi + atan(y/x) */+        bf_const_pi(T, prec1, BF_RNDF);+        T->sign = y->sign;+        bf_add(r, r, T, prec1, BF_RNDN);+        ret |= BF_ST_INEXACT;+    }++    bf_delete(T);+    return ret;+}++int bf_atan2(bf_t *r, const bf_t *y, const bf_t *x,+             limb_t prec, bf_flags_t flags)+{+    return bf_ziv_rounding(r, y, prec, flags, bf_atan2_internal, (void *)x);+}++static int bf_asin_internal(bf_t *r, const bf_t *a, limb_t prec, void *opaque)+{+    bf_context_t *s = r->ctx;+    BOOL is_acos = (BOOL)(intptr_t)opaque;+    bf_t T_s, *T = &T_s;+    limb_t prec1, prec2;+    +    /* asin(x) = atan(x/sqrt(1-x^2)) +       acos(x) = pi/2 - asin(x) */+    prec1 = prec + 8;+    /* increase the precision in x^2 to compensate the cancellation in+       (1-x^2) if x is close to 1 */+    /* XXX: use less precision when possible */+    if (a->expn >= 0)+        prec2 = BF_PREC_INF;+    else+        prec2 = prec1;+    bf_init(s, T);+    bf_mul(T, a, a, prec2, BF_RNDN);+    bf_neg(T);+    bf_add_si(T, T, 1, prec2, BF_RNDN);++    bf_sqrt(r, T, prec1, BF_RNDN);+    bf_div(T, a, r, prec1, BF_RNDN);+    if (is_acos)+        bf_neg(T);+    bf_atan_internal(r, T, prec1, (void *)(intptr_t)is_acos);+    bf_delete(T);+    return BF_ST_INEXACT;+}++int bf_asin(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    int res;++    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_set_zero(r, a->sign);+            return 0;+        }+    }+    bf_init(s, T);+    bf_set_ui(T, 1);+    res = bf_cmpu(a, T);+    bf_delete(T);+    if (res > 0) {+        bf_set_nan(r);+        return BF_ST_INVALID_OP;+    }+    +    /* small argument case: result = x+r(x) with r(x) = x^3/6 ++       O(X^5). We assume r(x) < 2^(3*EXP(x) - 2). */+    if (a->expn < 0) {+        slimb_t e;+        e = sat_add(2 * a->expn, a->expn - 2);+        if (e < a->expn - bf_max(prec + 2, a->len * LIMB_BITS + 2)) {+            bf_set(r, a);+            return bf_add_epsilon(r, r, e, a->sign, prec, flags);+        }+    }++    return bf_ziv_rounding(r, a, prec, flags, bf_asin_internal, (void *)FALSE);+}++int bf_acos(bf_t *r, const bf_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = r->ctx;+    bf_t T_s, *T = &T_s;+    int res;++    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bf_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF) {+            bf_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bf_const_pi(r, prec, flags);+            bf_mul_2exp(r, -1, BF_PREC_INF, BF_RNDZ);+            return BF_ST_INEXACT;+        }+    }+    bf_init(s, T);+    bf_set_ui(T, 1);+    res = bf_cmpu(a, T);+    bf_delete(T);+    if (res > 0) {+        bf_set_nan(r);+        return BF_ST_INVALID_OP;+    } else if (res == 0 && a->sign == 0) {+        bf_set_zero(r, 0);+        return 0;+    }+    +    return bf_ziv_rounding(r, a, prec, flags, bf_asin_internal, (void *)TRUE);+}++/***************************************************************/+/* decimal floating point numbers */++#ifdef USE_BF_DEC++#define adddq(r1, r0, a1, a0)                   \+    do {                                        \+        limb_t __t = r0;                        \+        r0 += (a0);                             \+        r1 += (a1) + (r0 < __t);                \+    } while (0)++#define subdq(r1, r0, a1, a0)                   \+    do {                                        \+        limb_t __t = r0;                        \+        r0 -= (a0);                             \+        r1 -= (a1) + (r0 > __t);                \+    } while (0)++#if LIMB_BITS == 64++/* Note: we assume __int128 is available */+#define muldq(r1, r0, a, b)                     \+    do {                                        \+        unsigned __int128 __t;                          \+        __t = (unsigned __int128)(a) * (unsigned __int128)(b);  \+        r0 = __t;                               \+        r1 = __t >> 64;                         \+    } while (0)++#define divdq(q, r, a1, a0, b)                  \+    do {                                        \+        unsigned __int128 __t;                  \+        limb_t __b = (b);                       \+        __t = ((unsigned __int128)(a1) << 64) | (a0);   \+        q = __t / __b;                                  \+        r = __t % __b;                                  \+    } while (0)++#else++#define muldq(r1, r0, a, b)                     \+    do {                                        \+        uint64_t __t;                          \+        __t = (uint64_t)(a) * (uint64_t)(b);  \+        r0 = __t;                               \+        r1 = __t >> 32;                         \+    } while (0)++#define divdq(q, r, a1, a0, b)                  \+    do {                                        \+        uint64_t __t;                  \+        limb_t __b = (b);                       \+        __t = ((uint64_t)(a1) << 32) | (a0);   \+        q = __t / __b;                                  \+        r = __t % __b;                                  \+    } while (0)++#endif /* LIMB_BITS != 64 */++static inline __maybe_unused limb_t shrd(limb_t low, limb_t high, long shift)+{+    if (shift != 0)+        low = (low >> shift) | (high << (LIMB_BITS - shift));+    return low;+}++static inline __maybe_unused limb_t shld(limb_t a1, limb_t a0, long shift)+{+    if (shift != 0)+        return (a1 << shift) | (a0 >> (LIMB_BITS - shift));+    else+        return a1;+}++#if LIMB_DIGITS == 19++/* WARNING: hardcoded for b = 1e19. It is assumed that:+   0 <= a1 < 2^63 */+#define divdq_base(q, r, a1, a0)\+do {\+    uint64_t __a0, __a1, __t0, __t1, __b = BF_DEC_BASE; \+    __a0 = a0;\+    __a1 = a1;\+    __t0 = __a1;\+    __t0 = shld(__t0, __a0, 1);\+    muldq(q, __t1, __t0, UINT64_C(17014118346046923173)); \+    muldq(__t1, __t0, q, __b);\+    subdq(__a1, __a0, __t1, __t0);\+    subdq(__a1, __a0, 1, __b * 2);    \+    __t0 = (slimb_t)__a1 >> 1; \+    q += 2 + __t0;\+    adddq(__a1, __a0, 0, __b & __t0);\+    q += __a1;                  \+    __a0 += __b & __a1;           \+    r = __a0;\+} while(0)++#elif LIMB_DIGITS == 9++/* WARNING: hardcoded for b = 1e9. It is assumed that:+   0 <= a1 < 2^29 */+#define divdq_base(q, r, a1, a0)\+do {\+    uint32_t __t0, __t1, __b = BF_DEC_BASE; \+    __t0 = a1;\+    __t1 = a0;\+    __t0 = (__t0 << 3) | (__t1 >> (32 - 3));    \+    muldq(q, __t1, __t0, 2305843009U);\+    r = a0 - q * __b;\+    __t1 = (r >= __b);\+    q += __t1;\+    if (__t1)\+        r -= __b;\+} while(0)++#endif++/* fast integer division by a fixed constant */++typedef struct FastDivData {+    limb_t m1; /* multiplier */+    int8_t shift1;+    int8_t shift2;+} FastDivData;++/* From "Division by Invariant Integers using Multiplication" by+   Torborn Granlund and Peter L. Montgomery */+/* d must be != 0 */+static inline __maybe_unused void fast_udiv_init(FastDivData *s, limb_t d)+{+    int l;+    limb_t q, r, m1;+    if (d == 1)+        l = 0;+    else+        l = 64 - clz64(d - 1);+    divdq(q, r, ((limb_t)1 << l) - d, 0, d);+    (void)r;+    m1 = q + 1;+    //    printf("d=%lu l=%d m1=0x%016lx\n", d, l, m1);+    s->m1 = m1;+    s->shift1 = l;+    if (s->shift1 > 1)+        s->shift1 = 1;+    s->shift2 = l - 1;+    if (s->shift2 < 0)+        s->shift2 = 0;+}++static inline limb_t fast_udiv(limb_t a, const FastDivData *s)+{+    limb_t t0, t1;+    muldq(t1, t0, s->m1, a);+    t0 = (a - t1) >> s->shift1;+    return (t1 + t0) >> s->shift2;+}++/* contains 10^i */+const limb_t mp_pow_dec[LIMB_DIGITS + 1] = {+    1U,+    10U,+    100U,+    1000U,+    10000U,+    100000U,+    1000000U,+    10000000U,+    100000000U,+    1000000000U,+#if LIMB_BITS == 64+    10000000000U,+    100000000000U,+    1000000000000U,+    10000000000000U,+    100000000000000U,+    1000000000000000U,+    10000000000000000U,+    100000000000000000U,+    1000000000000000000U,+    10000000000000000000U,+#endif+};++/* precomputed from fast_udiv_init(10^i) */+static const FastDivData mp_pow_div[LIMB_DIGITS + 1] = {+#if LIMB_BITS == 32+    { 0x00000001, 0, 0 },+    { 0x9999999a, 1, 3 },+    { 0x47ae147b, 1, 6 },+    { 0x0624dd30, 1, 9 },+    { 0xa36e2eb2, 1, 13 },+    { 0x4f8b588f, 1, 16 },+    { 0x0c6f7a0c, 1, 19 },+    { 0xad7f29ac, 1, 23 },+    { 0x5798ee24, 1, 26 },+    { 0x12e0be83, 1, 29 },+#else+    { 0x0000000000000001, 0, 0 },+    { 0x999999999999999a, 1, 3 },+    { 0x47ae147ae147ae15, 1, 6 },+    { 0x0624dd2f1a9fbe77, 1, 9 },+    { 0xa36e2eb1c432ca58, 1, 13 },+    { 0x4f8b588e368f0847, 1, 16 },+    { 0x0c6f7a0b5ed8d36c, 1, 19 },+    { 0xad7f29abcaf48579, 1, 23 },+    { 0x5798ee2308c39dfa, 1, 26 },+    { 0x12e0be826d694b2f, 1, 29 },+    { 0xb7cdfd9d7bdbab7e, 1, 33 },+    { 0x5fd7fe17964955fe, 1, 36 },+    { 0x19799812dea11198, 1, 39 },+    { 0xc25c268497681c27, 1, 43 },+    { 0x6849b86a12b9b01f, 1, 46 },+    { 0x203af9ee756159b3, 1, 49 },+    { 0xcd2b297d889bc2b7, 1, 53 },+    { 0x70ef54646d496893, 1, 56 },+    { 0x2725dd1d243aba0f, 1, 59 },+    { 0xd83c94fb6d2ac34d, 1, 63 },+#endif+};++/* divide by 10^shift with 0 <= shift <= LIMB_DIGITS */+static inline limb_t fast_shr_dec(limb_t a, int shift)+{+    return fast_udiv(a, &mp_pow_div[shift]);+}++/* division and remainder by 10^shift */+#define fast_shr_rem_dec(q, r, a, shift) q = fast_shr_dec(a, shift), r = a - q * mp_pow_dec[shift]+    +limb_t mp_add_dec(limb_t *res, const limb_t *op1, const limb_t *op2, +                  mp_size_t n, limb_t carry)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t k, a, v;++    k=carry;+    for(i=0;i<n;i++) {+        /* XXX: reuse the trick in add_mod */+        v = op1[i];+        a = v + op2[i] + k - base;+        k = a <= v;+        if (!k) +            a += base;+        res[i]=a;+    }+    return k;+}++limb_t mp_add_ui_dec(limb_t *tab, limb_t b, mp_size_t n)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t k, a, v;++    k=b;+    for(i=0;i<n;i++) {+        v = tab[i];+        a = v + k - base;+        k = a <= v;+        if (!k) +            a += base;+        tab[i] = a;+        if (k == 0)+            break;+    }+    return k;+}++limb_t mp_sub_dec(limb_t *res, const limb_t *op1, const limb_t *op2, +                  mp_size_t n, limb_t carry)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t k, v, a;++    k=carry;+    for(i=0;i<n;i++) {+        v = op1[i];+        a = v - op2[i] - k;+        k = a > v;+        if (k)+            a += base;+        res[i] = a;+    }+    return k;+}++limb_t mp_sub_ui_dec(limb_t *tab, limb_t b, mp_size_t n)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t k, v, a;+    +    k=b;+    for(i=0;i<n;i++) {+        v = tab[i];+        a = v - k;+        k = a > v;+        if (k)+            a += base;+        tab[i]=a;+        if (k == 0)+            break;+    }+    return k;+}++/* taba[] = taba[] * b + l. 0 <= b, l <= base - 1. Return the high carry */+limb_t mp_mul1_dec(limb_t *tabr, const limb_t *taba, mp_size_t n, +                   limb_t b, limb_t l)+{+    mp_size_t i;+    limb_t t0, t1, r;++    for(i = 0; i < n; i++) {+        muldq(t1, t0, taba[i], b);+        adddq(t1, t0, 0, l);+        divdq_base(l, r, t1, t0);+        tabr[i] = r;+    }+    return l;+}++/* tabr[] += taba[] * b. 0 <= b <= base - 1. Return the value to add+   to the high word */+limb_t mp_add_mul1_dec(limb_t *tabr, const limb_t *taba, mp_size_t n,+                       limb_t b)+{+    mp_size_t i;+    limb_t l, t0, t1, r;++    l = 0;+    for(i = 0; i < n; i++) {+        muldq(t1, t0, taba[i], b);+        adddq(t1, t0, 0, l);+        adddq(t1, t0, 0, tabr[i]);+        divdq_base(l, r, t1, t0);+        tabr[i] = r;+    }+    return l;+}++/* tabr[] -= taba[] * b. 0 <= b <= base - 1. Return the value to+   substract to the high word. */+limb_t mp_sub_mul1_dec(limb_t *tabr, const limb_t *taba, mp_size_t n,+                       limb_t b)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t l, t0, t1, r, a, v, c;++    /* XXX: optimize */+    l = 0;+    for(i = 0; i < n; i++) {+        muldq(t1, t0, taba[i], b);+        adddq(t1, t0, 0, l);+        divdq_base(l, r, t1, t0);+        v = tabr[i];+        a = v - r;+        c = a > v;+        if (c)+            a += base;+        /* never bigger than base because r = 0 when l = base - 1 */+        l += c;+        tabr[i] = a;+    }+    return l;+}++/* size of the result : op1_size + op2_size. */+void mp_mul_basecase_dec(limb_t *result, +                         const limb_t *op1, mp_size_t op1_size, +                         const limb_t *op2, mp_size_t op2_size) +{+    mp_size_t i;+    limb_t r;+    +    result[op1_size] = mp_mul1_dec(result, op1, op1_size, op2[0], 0);++    for(i=1;i<op2_size;i++) {+        r = mp_add_mul1_dec(result + i, op1, op1_size, op2[i]);+        result[i + op1_size] = r;+    }+}++/* taba[] = (taba[] + r*base^na) / b. 0 <= b < base. 0 <= r <+   b. Return the remainder. */+limb_t mp_div1_dec(limb_t *tabr, const limb_t *taba, mp_size_t na, +                   limb_t b, limb_t r)+{+    limb_t base = BF_DEC_BASE;+    mp_size_t i;+    limb_t t0, t1, q;+    int shift;++#if (BF_DEC_BASE % 2) == 0+    if (b == 2) {+        limb_t base_div2;+        /* Note: only works if base is even */+        base_div2 = base >> 1;+        if (r)+            r = base_div2;+        for(i = na - 1; i >= 0; i--) {+            t0 = taba[i];+            tabr[i] = (t0 >> 1) + r;+            r = 0;+            if (t0 & 1)+                r = base_div2;+        }+        if (r)+            r = 1;+    } else +#endif+    if (na >= UDIV1NORM_THRESHOLD) {+        shift = clz(b);+        if (shift == 0) {+            /* normalized case: b >= 2^(LIMB_BITS-1) */+            limb_t b_inv;+            b_inv = udiv1norm_init(b);+            for(i = na - 1; i >= 0; i--) {+                muldq(t1, t0, r, base);+                adddq(t1, t0, 0, taba[i]);+                q = udiv1norm(&r, t1, t0, b, b_inv);+                tabr[i] = q;+            }+        } else {+            limb_t b_inv;+            b <<= shift;+            b_inv = udiv1norm_init(b);+            for(i = na - 1; i >= 0; i--) {+                muldq(t1, t0, r, base);+                adddq(t1, t0, 0, taba[i]);+                t1 = (t1 << shift) | (t0 >> (LIMB_BITS - shift));+                t0 <<= shift;+                q = udiv1norm(&r, t1, t0, b, b_inv);+                r >>= shift;+                tabr[i] = q;+            }+        }+    } else {+        for(i = na - 1; i >= 0; i--) {+            muldq(t1, t0, r, base);+            adddq(t1, t0, 0, taba[i]);+            divdq(q, r, t1, t0, b);+            tabr[i] = q;+        }+    }+    return r;+}++static __maybe_unused void mp_print_str_dec(const char *str,+                                       const limb_t *tab, slimb_t n)+{+    slimb_t i;+    printf("%s=", str);+    for(i = n - 1; i >= 0; i--) {+        if (i != n - 1)+            printf("_");+        printf("%0*" PRIu_LIMB, LIMB_DIGITS, tab[i]);+    }+    printf("\n");+}++static __maybe_unused void mp_print_str_h_dec(const char *str,+                                              const limb_t *tab, slimb_t n,+                                              limb_t high)+{+    slimb_t i;+    printf("%s=", str);+    printf("%0*" PRIu_LIMB, LIMB_DIGITS, high);+    for(i = n - 1; i >= 0; i--) {+        printf("_");+        printf("%0*" PRIu_LIMB, LIMB_DIGITS, tab[i]);+    }+    printf("\n");+}++//#define DEBUG_DIV_SLOW++#define DIV_STATIC_ALLOC_LEN 16++/* return q = a / b and r = a % b. ++   taba[na] must be allocated if tabb1[nb - 1] < B / 2.  tabb1[nb - 1]+   must be != zero. na must be >= nb. 's' can be NULL if tabb1[nb - 1]+   >= B / 2.++   The remainder is is returned in taba and contains nb libms. tabq+   contains na - nb + 1 limbs. No overlap is permitted.++   Running time of the standard method: (na - nb + 1) * nb+   Return 0 if OK, -1 if memory alloc error+*/+/* XXX: optimize */+static int mp_div_dec(bf_context_t *s, limb_t *tabq,+                      limb_t *taba, mp_size_t na, +                      const limb_t *tabb1, mp_size_t nb)+{+    limb_t base = BF_DEC_BASE;+    limb_t r, mult, t0, t1, a, c, q, v, *tabb;+    mp_size_t i, j;+    limb_t static_tabb[DIV_STATIC_ALLOC_LEN];+    +#ifdef DEBUG_DIV_SLOW+    mp_print_str_dec("a", taba, na);+    mp_print_str_dec("b", tabb1, nb);+#endif++    /* normalize tabb */+    r = tabb1[nb - 1];+    assert(r != 0);+    i = na - nb;+    if (r >= BF_DEC_BASE / 2) {+        mult = 1;+        tabb = (limb_t *)tabb1;+        q = 1;+        for(j = nb - 1; j >= 0; j--) {+            if (taba[i + j] != tabb[j]) {+                if (taba[i + j] < tabb[j])+                    q = 0;+                break;+            }+        }+        tabq[i] = q;+        if (q) {+            mp_sub_dec(taba + i, taba + i, tabb, nb, 0);+        }+        i--;+    } else {+        mult = base / (r + 1);+        if (likely(nb <= DIV_STATIC_ALLOC_LEN)) {+            tabb = static_tabb;+        } else {+            tabb = bf_malloc(s, sizeof(limb_t) * nb);+            if (!tabb)+                return -1;+        }+        mp_mul1_dec(tabb, tabb1, nb, mult, 0);+        taba[na] = mp_mul1_dec(taba, taba, na, mult, 0);+    }++#ifdef DEBUG_DIV_SLOW+    printf("mult=" FMT_LIMB "\n", mult);+    mp_print_str_dec("a_norm", taba, na + 1);+    mp_print_str_dec("b_norm", tabb, nb);+#endif++    for(; i >= 0; i--) {+        if (unlikely(taba[i + nb] >= tabb[nb - 1])) {+            /* XXX: check if it is really possible */+            q = base - 1;+        } else {+            muldq(t1, t0, taba[i + nb], base);+            adddq(t1, t0, 0, taba[i + nb - 1]);+            divdq(q, r, t1, t0, tabb[nb - 1]);+        }+        //        printf("i=%d q1=%ld\n", i, q);++        r = mp_sub_mul1_dec(taba + i, tabb, nb, q);+        //        mp_dump("r1", taba + i, nb, bd);+        //        printf("r2=%ld\n", r);++        v = taba[i + nb];+        a = v - r;+        c = a > v;+        if (c)+            a += base;+        taba[i + nb] = a;++        if (c != 0) {+            /* negative result */+            for(;;) {+                q--;+                c = mp_add_dec(taba + i, taba + i, tabb, nb, 0);+                /* propagate carry and test if positive result */+                if (c != 0) {+                    if (++taba[i + nb] == base) {+                        break;+                    }+                }+            }+        }+        tabq[i] = q;+    }++#ifdef DEBUG_DIV_SLOW+    mp_print_str_dec("q", tabq, na - nb + 1);+    mp_print_str_dec("r", taba, nb);+#endif++    /* remove the normalization */+    if (mult != 1) {+        mp_div1_dec(taba, taba, nb, mult, 0);+        if (unlikely(tabb != static_tabb))+            bf_free(s, tabb);+    }+    return 0;+}++/* divide by 10^shift */+static limb_t mp_shr_dec(limb_t *tab_r, const limb_t *tab, mp_size_t n, +                         limb_t shift, limb_t high)+{+    mp_size_t i;+    limb_t l, a, q, r;++    assert(shift >= 1 && shift < LIMB_DIGITS);+    l = high;+    for(i = n - 1; i >= 0; i--) {+        a = tab[i];+        fast_shr_rem_dec(q, r, a, shift);+        tab_r[i] = q + l * mp_pow_dec[LIMB_DIGITS - shift];+        l = r;+    }+    return l;+}++/* multiply by 10^shift */+static limb_t mp_shl_dec(limb_t *tab_r, const limb_t *tab, mp_size_t n, +                         limb_t shift, limb_t low)+{+    mp_size_t i;+    limb_t l, a, q, r;++    assert(shift >= 1 && shift < LIMB_DIGITS);+    l = low;+    for(i = 0; i < n; i++) {+        a = tab[i];+        fast_shr_rem_dec(q, r, a, LIMB_DIGITS - shift);+        tab_r[i] = r * mp_pow_dec[shift] + l;+        l = q;+    }+    return l;+}++static limb_t mp_sqrtrem2_dec(limb_t *tabs, limb_t *taba)+{+    int k;+    dlimb_t a, b, r;+    limb_t taba1[2], s, r0, r1;++    /* convert to binary and normalize */+    a = (dlimb_t)taba[1] * BF_DEC_BASE + taba[0];+    k = clz(a >> LIMB_BITS) & ~1;+    b = a << k;+    taba1[0] = b;+    taba1[1] = b >> LIMB_BITS;+    mp_sqrtrem2(&s, taba1);+    s >>= (k >> 1);+    /* convert the remainder back to decimal */+    r = a - (dlimb_t)s * (dlimb_t)s;+    divdq_base(r1, r0, r >> LIMB_BITS, r);+    taba[0] = r0;+    tabs[0] = s;+    return r1;+}++//#define DEBUG_SQRTREM_DEC++/* tmp_buf must contain (n / 2 + 1 limbs) */+static limb_t mp_sqrtrem_rec_dec(limb_t *tabs, limb_t *taba, limb_t n,+                                 limb_t *tmp_buf)+{+    limb_t l, h, rh, ql, qh, c, i;+    +    if (n == 1)+        return mp_sqrtrem2_dec(tabs, taba);+#ifdef DEBUG_SQRTREM_DEC+    mp_print_str_dec("a", taba, 2 * n);+#endif+    l = n / 2;+    h = n - l;+    qh = mp_sqrtrem_rec_dec(tabs + l, taba + 2 * l, h, tmp_buf);+#ifdef DEBUG_SQRTREM_DEC+    mp_print_str_dec("s1", tabs + l, h);+    mp_print_str_h_dec("r1", taba + 2 * l, h, qh);+    mp_print_str_h_dec("r2", taba + l, n, qh);+#endif+    +    /* the remainder is in taba + 2 * l. Its high bit is in qh */+    if (qh) {+        mp_sub_dec(taba + 2 * l, taba + 2 * l, tabs + l, h, 0);+    }+    /* instead of dividing by 2*s, divide by s (which is normalized)+       and update q and r */+    mp_div_dec(NULL, tmp_buf, taba + l, n, tabs + l, h);+    qh += tmp_buf[l];+    for(i = 0; i < l; i++)+        tabs[i] = tmp_buf[i];+    ql = mp_div1_dec(tabs, tabs, l, 2, qh & 1);+    qh = qh >> 1; /* 0 or 1 */+    if (ql)+        rh = mp_add_dec(taba + l, taba + l, tabs + l, h, 0);+    else+        rh = 0;+#ifdef DEBUG_SQRTREM_DEC+    mp_print_str_h_dec("q", tabs, l, qh);+    mp_print_str_h_dec("u", taba + l, h, rh);+#endif+    +    mp_add_ui_dec(tabs + l, qh, h);+#ifdef DEBUG_SQRTREM_DEC+    mp_print_str_dec("s2", tabs, n);+#endif+    +    /* q = qh, tabs[l - 1 ... 0], r = taba[n - 1 ... l] */+    /* subtract q^2. if qh = 1 then q = B^l, so we can take shortcuts */+    if (qh) {+        c = qh;+    } else {+        mp_mul_basecase_dec(taba + n, tabs, l, tabs, l);+        c = mp_sub_dec(taba, taba, taba + n, 2 * l, 0);+    }+    rh -= mp_sub_ui_dec(taba + 2 * l, c, n - 2 * l);+    if ((slimb_t)rh < 0) {+        mp_sub_ui_dec(tabs, 1, n);+        rh += mp_add_mul1_dec(taba, tabs, n, 2);+        rh += mp_add_ui_dec(taba, 1, n);+    }+    return rh;+}++/* 'taba' has 2*n limbs with n >= 1 and taba[2*n-1] >= B/4. Return (s,+   r) with s=floor(sqrt(a)) and r=a-s^2. 0 <= r <= 2 * s. tabs has n+   limbs. r is returned in the lower n limbs of taba. Its r[n] is the+   returned value of the function. */+int mp_sqrtrem_dec(bf_context_t *s, limb_t *tabs, limb_t *taba, limb_t n)+{+    limb_t tmp_buf1[8];+    limb_t *tmp_buf;+    mp_size_t n2;+    n2 = n / 2 + 1;+    if (n2 <= countof(tmp_buf1)) {+        tmp_buf = tmp_buf1;+    } else {+        tmp_buf = bf_malloc(s, sizeof(limb_t) * n2);+        if (!tmp_buf)+            return -1;+    }+    taba[n] = mp_sqrtrem_rec_dec(tabs, taba, n, tmp_buf);+    if (tmp_buf != tmp_buf1)+        bf_free(s, tmp_buf);+    return 0;+}++/* return the number of leading zero digits, from 0 to LIMB_DIGITS */+static int clz_dec(limb_t a)+{+    if (a == 0)+        return LIMB_DIGITS;+    switch(LIMB_BITS - 1 - clz(a)) {+    case 0: /* 1-1 */+        return LIMB_DIGITS - 1;+    case 1: /* 2-3 */+        return LIMB_DIGITS - 1;+    case 2: /* 4-7 */+        return LIMB_DIGITS - 1;+    case 3: /* 8-15 */+        if (a < 10)+            return LIMB_DIGITS - 1;+        else+            return LIMB_DIGITS - 2;+    case 4: /* 16-31 */+        return LIMB_DIGITS - 2;+    case 5: /* 32-63 */+        return LIMB_DIGITS - 2;+    case 6: /* 64-127 */+        if (a < 100)+            return LIMB_DIGITS - 2;+        else+            return LIMB_DIGITS - 3;+    case 7: /* 128-255 */+        return LIMB_DIGITS - 3;+    case 8: /* 256-511 */+        return LIMB_DIGITS - 3;+    case 9: /* 512-1023 */+        if (a < 1000)+            return LIMB_DIGITS - 3;+        else+            return LIMB_DIGITS - 4;+    case 10: /* 1024-2047 */+        return LIMB_DIGITS - 4;+    case 11: /* 2048-4095 */+        return LIMB_DIGITS - 4;+    case 12: /* 4096-8191 */+        return LIMB_DIGITS - 4;+    case 13: /* 8192-16383 */+        if (a < 10000)+            return LIMB_DIGITS - 4;+        else+            return LIMB_DIGITS - 5;+    case 14: /* 16384-32767 */+        return LIMB_DIGITS - 5;+    case 15: /* 32768-65535 */+        return LIMB_DIGITS - 5;+    case 16: /* 65536-131071 */+        if (a < 100000)+            return LIMB_DIGITS - 5;+        else+            return LIMB_DIGITS - 6;+    case 17: /* 131072-262143 */+        return LIMB_DIGITS - 6;+    case 18: /* 262144-524287 */+        return LIMB_DIGITS - 6;+    case 19: /* 524288-1048575 */+        if (a < 1000000)+            return LIMB_DIGITS - 6;+        else+            return LIMB_DIGITS - 7;+    case 20: /* 1048576-2097151 */+        return LIMB_DIGITS - 7;+    case 21: /* 2097152-4194303 */+        return LIMB_DIGITS - 7;+    case 22: /* 4194304-8388607 */+        return LIMB_DIGITS - 7;+    case 23: /* 8388608-16777215 */+        if (a < 10000000)+            return LIMB_DIGITS - 7;+        else+            return LIMB_DIGITS - 8;+    case 24: /* 16777216-33554431 */+        return LIMB_DIGITS - 8;+    case 25: /* 33554432-67108863 */+        return LIMB_DIGITS - 8;+    case 26: /* 67108864-134217727 */+        if (a < 100000000)+            return LIMB_DIGITS - 8;+        else+            return LIMB_DIGITS - 9;+#if LIMB_BITS == 64+    case 27: /* 134217728-268435455 */+        return LIMB_DIGITS - 9;+    case 28: /* 268435456-536870911 */+        return LIMB_DIGITS - 9;+    case 29: /* 536870912-1073741823 */+        if (a < 1000000000)+            return LIMB_DIGITS - 9;+        else+            return LIMB_DIGITS - 10;+    case 30: /* 1073741824-2147483647 */+        return LIMB_DIGITS - 10;+    case 31: /* 2147483648-4294967295 */+        return LIMB_DIGITS - 10;+    case 32: /* 4294967296-8589934591 */+        return LIMB_DIGITS - 10;+    case 33: /* 8589934592-17179869183 */+        if (a < 10000000000)+            return LIMB_DIGITS - 10;+        else+            return LIMB_DIGITS - 11;+    case 34: /* 17179869184-34359738367 */+        return LIMB_DIGITS - 11;+    case 35: /* 34359738368-68719476735 */+        return LIMB_DIGITS - 11;+    case 36: /* 68719476736-137438953471 */+        if (a < 100000000000)+            return LIMB_DIGITS - 11;+        else+            return LIMB_DIGITS - 12;+    case 37: /* 137438953472-274877906943 */+        return LIMB_DIGITS - 12;+    case 38: /* 274877906944-549755813887 */+        return LIMB_DIGITS - 12;+    case 39: /* 549755813888-1099511627775 */+        if (a < 1000000000000)+            return LIMB_DIGITS - 12;+        else+            return LIMB_DIGITS - 13;+    case 40: /* 1099511627776-2199023255551 */+        return LIMB_DIGITS - 13;+    case 41: /* 2199023255552-4398046511103 */+        return LIMB_DIGITS - 13;+    case 42: /* 4398046511104-8796093022207 */+        return LIMB_DIGITS - 13;+    case 43: /* 8796093022208-17592186044415 */+        if (a < 10000000000000)+            return LIMB_DIGITS - 13;+        else+            return LIMB_DIGITS - 14;+    case 44: /* 17592186044416-35184372088831 */+        return LIMB_DIGITS - 14;+    case 45: /* 35184372088832-70368744177663 */+        return LIMB_DIGITS - 14;+    case 46: /* 70368744177664-140737488355327 */+        if (a < 100000000000000)+            return LIMB_DIGITS - 14;+        else+            return LIMB_DIGITS - 15;+    case 47: /* 140737488355328-281474976710655 */+        return LIMB_DIGITS - 15;+    case 48: /* 281474976710656-562949953421311 */+        return LIMB_DIGITS - 15;+    case 49: /* 562949953421312-1125899906842623 */+        if (a < 1000000000000000)+            return LIMB_DIGITS - 15;+        else+            return LIMB_DIGITS - 16;+    case 50: /* 1125899906842624-2251799813685247 */+        return LIMB_DIGITS - 16;+    case 51: /* 2251799813685248-4503599627370495 */+        return LIMB_DIGITS - 16;+    case 52: /* 4503599627370496-9007199254740991 */+        return LIMB_DIGITS - 16;+    case 53: /* 9007199254740992-18014398509481983 */+        if (a < 10000000000000000)+            return LIMB_DIGITS - 16;+        else+            return LIMB_DIGITS - 17;+    case 54: /* 18014398509481984-36028797018963967 */+        return LIMB_DIGITS - 17;+    case 55: /* 36028797018963968-72057594037927935 */+        return LIMB_DIGITS - 17;+    case 56: /* 72057594037927936-144115188075855871 */+        if (a < 100000000000000000)+            return LIMB_DIGITS - 17;+        else+            return LIMB_DIGITS - 18;+    case 57: /* 144115188075855872-288230376151711743 */+        return LIMB_DIGITS - 18;+    case 58: /* 288230376151711744-576460752303423487 */+        return LIMB_DIGITS - 18;+    case 59: /* 576460752303423488-1152921504606846975 */+        if (a < 1000000000000000000)+            return LIMB_DIGITS - 18;+        else+            return LIMB_DIGITS - 19;+#endif+    default:+        return 0;+    }+}++/* for debugging */+void bfdec_print_str(const char *str, const bfdec_t *a)+{+    slimb_t i;+    printf("%s=", str);++    if (a->expn == BF_EXP_NAN) {+        printf("NaN");+    } else {+        if (a->sign)+            putchar('-');+        if (a->expn == BF_EXP_ZERO) {+            putchar('0');+        } else if (a->expn == BF_EXP_INF) {+            printf("Inf");+        } else {+            printf("0.");+            for(i = a->len - 1; i >= 0; i--)+                printf("%0*" PRIu_LIMB, LIMB_DIGITS, a->tab[i]);+            printf("e%" PRId_LIMB, a->expn);+        }+    }+    printf("\n");+}++/* return != 0 if one digit between 0 and bit_pos inclusive is not zero. */+static inline limb_t scan_digit_nz(const bfdec_t *r, slimb_t bit_pos)+{+    slimb_t pos;+    limb_t v, q;+    int shift;++    if (bit_pos < 0)+        return 0;+    pos = (limb_t)bit_pos / LIMB_DIGITS;+    shift = (limb_t)bit_pos % LIMB_DIGITS;+    fast_shr_rem_dec(q, v, r->tab[pos], shift + 1);+    (void)q;+    if (v != 0)+        return 1;+    pos--;+    while (pos >= 0) {+        if (r->tab[pos] != 0)+            return 1;+        pos--;+    }+    return 0;+}++static limb_t get_digit(const limb_t *tab, limb_t len, slimb_t pos)+{+    slimb_t i;+    int shift;+    i = floor_div(pos, LIMB_DIGITS);+    if (i < 0 || i >= len)+        return 0;+    shift = pos - i * LIMB_DIGITS;+    return fast_shr_dec(tab[i], shift) % 10;+}++#if 0+static limb_t get_digits(const limb_t *tab, limb_t len, slimb_t pos)+{+    limb_t a0, a1;+    int shift;+    slimb_t i;+    +    i = floor_div(pos, LIMB_DIGITS);+    shift = pos - i * LIMB_DIGITS;+    if (i >= 0 && i < len)+        a0 = tab[i];+    else+        a0 = 0;+    if (shift == 0) {+        return a0;+    } else {+        i++;+        if (i >= 0 && i < len)+            a1 = tab[i];+        else+            a1 = 0;+        return fast_shr_dec(a0, shift) ++            fast_urem(a1, &mp_pow_div[LIMB_DIGITS - shift]) *+            mp_pow_dec[shift];+    }+}+#endif++/* return the addend for rounding. Note that prec can be <= 0 for bf_rint() */+static int bfdec_get_rnd_add(int *pret, const bfdec_t *r, limb_t l,+                             slimb_t prec, int rnd_mode)+{+    int add_one, inexact;+    limb_t digit1, digit0;+    +    //    bfdec_print_str("get_rnd_add", r);+    if (rnd_mode == BF_RNDF) {+        digit0 = 1; /* faithful rounding does not honor the INEXACT flag */+    } else {+        /* starting limb for bit 'prec + 1' */+        digit0 = scan_digit_nz(r, l * LIMB_DIGITS - 1 - bf_max(0, prec + 1));+    }++    /* get the digit at 'prec' */+    digit1 = get_digit(r->tab, l, l * LIMB_DIGITS - 1 - prec);+    inexact = (digit1 | digit0) != 0;+    +    add_one = 0;+    switch(rnd_mode) {+    case BF_RNDZ:+        break;+    case BF_RNDN:+        if (digit1 == 5) {+            if (digit0) {+                add_one = 1;+            } else {+                /* round to even */+                add_one =+                    get_digit(r->tab, l, l * LIMB_DIGITS - 1 - (prec - 1)) & 1;+            }+        } else if (digit1 > 5) {+            add_one = 1;+        }+        break;+    case BF_RNDD:+    case BF_RNDU:+        if (r->sign == (rnd_mode == BF_RNDD))+            add_one = inexact;+        break;+    case BF_RNDNA:+    case BF_RNDF:+        add_one = (digit1 >= 5);+        break;+    case BF_RNDA:+        add_one = inexact;+        break;+    default:+        abort();+    }+    +    if (inexact)+        *pret |= BF_ST_INEXACT;+    return add_one;+}++/* round to prec1 bits assuming 'r' is non zero and finite. 'r' is+   assumed to have length 'l' (1 <= l <= r->len). prec1 can be+   BF_PREC_INF. BF_FLAG_SUBNORMAL is not supported. Cannot fail with+   BF_ST_MEM_ERROR.+ */+static int __bfdec_round(bfdec_t *r, limb_t prec1, bf_flags_t flags, limb_t l)+{+    int shift, add_one, rnd_mode, ret;+    slimb_t i, bit_pos, pos, e_min, e_max, e_range, prec;++    /* XXX: align to IEEE 754 2008 for decimal numbers ? */+    e_range = (limb_t)1 << (bf_get_exp_bits(flags) - 1);+    e_min = -e_range + 3;+    e_max = e_range;+    +    if (flags & BF_FLAG_RADPNT_PREC) {+        /* 'prec' is the precision after the decimal point */+        if (prec1 != BF_PREC_INF)+            prec = r->expn + prec1;+        else+            prec = prec1;+    } else if (unlikely(r->expn < e_min) && (flags & BF_FLAG_SUBNORMAL)) {+        /* restrict the precision in case of potentially subnormal+           result */+        assert(prec1 != BF_PREC_INF);+        prec = prec1 - (e_min - r->expn);+    } else {+        prec = prec1;+    }+    +    /* round to prec bits */+    rnd_mode = flags & BF_RND_MASK;+    ret = 0;+    add_one = bfdec_get_rnd_add(&ret, r, l, prec, rnd_mode);+    +    if (prec <= 0) {+        if (add_one) {+            bfdec_resize(r, 1); /* cannot fail because r is non zero */+            r->tab[0] = BF_DEC_BASE / 10;+            r->expn += 1 - prec;+            ret |= BF_ST_UNDERFLOW | BF_ST_INEXACT;+            return ret;+        } else {+            goto underflow;+        }+    } else if (add_one) {+        limb_t carry;+        +        /* add one starting at digit 'prec - 1' */+        bit_pos = l * LIMB_DIGITS - 1 - (prec - 1);+        pos = bit_pos / LIMB_DIGITS;+        carry = mp_pow_dec[bit_pos % LIMB_DIGITS];+        carry = mp_add_ui_dec(r->tab + pos, carry, l - pos);+        if (carry) {+            /* shift right by one digit */+            mp_shr_dec(r->tab + pos, r->tab + pos, l - pos, 1, 1);+            r->expn++;+        }+    }+    +    /* check underflow */+    if (unlikely(r->expn < e_min)) {+        if (flags & BF_FLAG_SUBNORMAL) {+            /* if inexact, also set the underflow flag */+            if (ret & BF_ST_INEXACT)+                ret |= BF_ST_UNDERFLOW;+        } else {+        underflow:+            bfdec_set_zero(r, r->sign);+            ret |= BF_ST_UNDERFLOW | BF_ST_INEXACT;+            return ret;+        }+    }+    +    /* check overflow */+    if (unlikely(r->expn > e_max)) {+        bfdec_set_inf(r, r->sign);+        ret |= BF_ST_OVERFLOW | BF_ST_INEXACT;+        return ret;+    }+    +    /* keep the bits starting at 'prec - 1' */+    bit_pos = l * LIMB_DIGITS - 1 - (prec - 1);+    i = floor_div(bit_pos, LIMB_DIGITS);+    if (i >= 0) {+        shift = smod(bit_pos, LIMB_DIGITS);+        if (shift != 0) {+            r->tab[i] = fast_shr_dec(r->tab[i], shift) *+                mp_pow_dec[shift];+        }+    } else {+        i = 0;+    }+    /* remove trailing zeros */+    while (r->tab[i] == 0)+        i++;+    if (i > 0) {+        l -= i;+        memmove(r->tab, r->tab + i, l * sizeof(limb_t));+    }+    bfdec_resize(r, l); /* cannot fail */+    return ret;+}++/* Cannot fail with BF_ST_MEM_ERROR. */+int bfdec_round(bfdec_t *r, limb_t prec, bf_flags_t flags)+{+    if (r->len == 0)+        return 0;+    return __bfdec_round(r, prec, flags, r->len);+}++/* 'r' must be a finite number. Cannot fail with BF_ST_MEM_ERROR.  */+int bfdec_normalize_and_round(bfdec_t *r, limb_t prec1, bf_flags_t flags)+{+    limb_t l, v;+    int shift, ret;+    +    //    bfdec_print_str("bf_renorm", r);+    l = r->len;+    while (l > 0 && r->tab[l - 1] == 0)+        l--;+    if (l == 0) {+        /* zero */+        r->expn = BF_EXP_ZERO;+        bfdec_resize(r, 0); /* cannot fail */+        ret = 0;+    } else {+        r->expn -= (r->len - l) * LIMB_DIGITS;+        /* shift to have the MSB set to '1' */+        v = r->tab[l - 1];+        shift = clz_dec(v);+        if (shift != 0) {+            mp_shl_dec(r->tab, r->tab, l, shift, 0);+            r->expn -= shift;+        }+        ret = __bfdec_round(r, prec1, flags, l);+    }+    //    bf_print_str("r_final", r);+    return ret;+}++int bfdec_set_ui(bfdec_t *r, uint64_t v)+{+#if LIMB_BITS == 32+    if (v >= BF_DEC_BASE * BF_DEC_BASE) {+        if (bfdec_resize(r, 3))+            goto fail;+        r->tab[0] = v % BF_DEC_BASE;+        v /= BF_DEC_BASE;+        r->tab[1] = v % BF_DEC_BASE;+        r->tab[2] = v / BF_DEC_BASE;+        r->expn = 3 * LIMB_DIGITS;+    } else+#endif+    if (v >= BF_DEC_BASE) {+        if (bfdec_resize(r, 2))+            goto fail;+        r->tab[0] = v % BF_DEC_BASE;+        r->tab[1] = v / BF_DEC_BASE;+        r->expn = 2 * LIMB_DIGITS;+    } else {+        if (bfdec_resize(r, 1))+            goto fail;+        r->tab[0] = v;+        r->expn = LIMB_DIGITS;+    }+    r->sign = 0;+    return bfdec_normalize_and_round(r, BF_PREC_INF, 0);+ fail:+    bfdec_set_nan(r);+    return BF_ST_MEM_ERROR;+}++int bfdec_set_si(bfdec_t *r, int64_t v)+{+    int ret;+    if (v < 0) {+        ret = bfdec_set_ui(r, -v);+        r->sign = 1;+    } else {+        ret = bfdec_set_ui(r, v);+    }+    return ret;+}++static int bfdec_add_internal(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec, bf_flags_t flags, int b_neg)+{+    bf_context_t *s = r->ctx;+    int is_sub, cmp_res, a_sign, b_sign, ret;++    a_sign = a->sign;+    b_sign = b->sign ^ b_neg;+    is_sub = a_sign ^ b_sign;+    cmp_res = bfdec_cmpu(a, b);+    if (cmp_res < 0) {+        const bfdec_t *tmp;+        tmp = a;+        a = b;+        b = tmp;+        a_sign = b_sign; /* b_sign is never used later */+    }+    /* abs(a) >= abs(b) */+    if (cmp_res == 0 && is_sub && a->expn < BF_EXP_INF) {+        /* zero result */+        bfdec_set_zero(r, (flags & BF_RND_MASK) == BF_RNDD);+        ret = 0;+    } else if (a->len == 0 || b->len == 0) {+        ret = 0;+        if (a->expn >= BF_EXP_INF) {+            if (a->expn == BF_EXP_NAN) {+                /* at least one operand is NaN */+                bfdec_set_nan(r);+                ret = 0;+            } else if (b->expn == BF_EXP_INF && is_sub) {+                /* infinities with different signs */+                bfdec_set_nan(r);+                ret = BF_ST_INVALID_OP;+            } else {+                bfdec_set_inf(r, a_sign);+            }+        } else {+            /* at least one zero and not subtract */+            if (bfdec_set(r, a))+                return BF_ST_MEM_ERROR;+            r->sign = a_sign;+            goto renorm;+        }+    } else {+        slimb_t d, a_offset, b_offset, i, r_len;+        limb_t carry;+        limb_t *b1_tab;+        int b_shift;+        mp_size_t b1_len;+        +        d = a->expn - b->expn;++        /* XXX: not efficient in time and memory if the precision is+           not infinite */+        r_len = bf_max(a->len, b->len + (d + LIMB_DIGITS - 1) / LIMB_DIGITS);+        if (bfdec_resize(r, r_len))+            goto fail;+        r->sign = a_sign;+        r->expn = a->expn;++        a_offset = r_len - a->len;+        for(i = 0; i < a_offset; i++)+            r->tab[i] = 0;+        for(i = 0; i < a->len; i++)+            r->tab[a_offset + i] = a->tab[i];+        +        b_shift = d % LIMB_DIGITS;+        if (b_shift == 0) {+            b1_len = b->len;+            b1_tab = (limb_t *)b->tab;+        } else {+            b1_len = b->len + 1;+            b1_tab = bf_malloc(s, sizeof(limb_t) * b1_len);+            if (!b1_tab)+                goto fail;+            b1_tab[0] = mp_shr_dec(b1_tab + 1, b->tab, b->len, b_shift, 0) *+                mp_pow_dec[LIMB_DIGITS - b_shift];+        }+        b_offset = r_len - (b->len + (d + LIMB_DIGITS - 1) / LIMB_DIGITS);+        +        if (is_sub) {+            carry = mp_sub_dec(r->tab + b_offset, r->tab + b_offset,+                               b1_tab, b1_len, 0);+            if (carry != 0) {+                carry = mp_sub_ui_dec(r->tab + b_offset + b1_len, carry,+                                      r_len - (b_offset + b1_len));+                assert(carry == 0);+            }+        } else {+            carry = mp_add_dec(r->tab + b_offset, r->tab + b_offset,+                               b1_tab, b1_len, 0);+            if (carry != 0) {+                carry = mp_add_ui_dec(r->tab + b_offset + b1_len, carry,+                                      r_len - (b_offset + b1_len));+            }+            if (carry != 0) {+                if (bfdec_resize(r, r_len + 1)) {+                    if (b_shift != 0)+                        bf_free(s, b1_tab);+                    goto fail;+                }+                r->tab[r_len] = 1;+                r->expn += LIMB_DIGITS;+            }+        }+        if (b_shift != 0)+            bf_free(s, b1_tab);+    renorm:+        ret = bfdec_normalize_and_round(r, prec, flags);+    }+    return ret;+ fail:+    bfdec_set_nan(r);+    return BF_ST_MEM_ERROR;+}++static int __bfdec_add(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+                     bf_flags_t flags)+{+    return bfdec_add_internal(r, a, b, prec, flags, 0);+}++static int __bfdec_sub(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+                     bf_flags_t flags)+{+    return bfdec_add_internal(r, a, b, prec, flags, 1);+}++int bfdec_add(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+              bf_flags_t flags)+{+    return bf_op2((bf_t *)r, (bf_t *)a, (bf_t *)b, prec, flags,+                  (bf_op2_func_t *)__bfdec_add);+}++int bfdec_sub(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+              bf_flags_t flags)+{+    return bf_op2((bf_t *)r, (bf_t *)a, (bf_t *)b, prec, flags,+                  (bf_op2_func_t *)__bfdec_sub);+}++int bfdec_mul(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+              bf_flags_t flags)+{+    int ret, r_sign;++    if (a->len < b->len) {+        const bfdec_t *tmp = a;+        a = b;+        b = tmp;+    }+    r_sign = a->sign ^ b->sign;+    /* here b->len <= a->len */+    if (b->len == 0) {+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bfdec_set_nan(r);+            ret = 0;+        } else if (a->expn == BF_EXP_INF || b->expn == BF_EXP_INF) {+            if ((a->expn == BF_EXP_INF && b->expn == BF_EXP_ZERO) ||+                (a->expn == BF_EXP_ZERO && b->expn == BF_EXP_INF)) {+                bfdec_set_nan(r);+                ret = BF_ST_INVALID_OP;+            } else {+                bfdec_set_inf(r, r_sign);+                ret = 0;+            }+        } else {+            bfdec_set_zero(r, r_sign);+            ret = 0;+        }+    } else {+        bfdec_t tmp, *r1 = NULL;+        limb_t a_len, b_len;+        limb_t *a_tab, *b_tab;+            +        a_len = a->len;+        b_len = b->len;+        a_tab = a->tab;+        b_tab = b->tab;+        +        if (r == a || r == b) {+            bfdec_init(r->ctx, &tmp);+            r1 = r;+            r = &tmp;+        }+        if (bfdec_resize(r, a_len + b_len)) {+            bfdec_set_nan(r);+            ret = BF_ST_MEM_ERROR;+            goto done;+        }+        mp_mul_basecase_dec(r->tab, a_tab, a_len, b_tab, b_len);+        r->sign = r_sign;+        r->expn = a->expn + b->expn;+        ret = bfdec_normalize_and_round(r, prec, flags);+    done:+        if (r == &tmp)+            bfdec_move(r1, &tmp);+    }+    return ret;+}++int bfdec_mul_si(bfdec_t *r, const bfdec_t *a, int64_t b1, limb_t prec,+                 bf_flags_t flags)+{+    bfdec_t b;+    int ret;+    bfdec_init(r->ctx, &b);+    ret = bfdec_set_si(&b, b1);+    ret |= bfdec_mul(r, a, &b, prec, flags);+    bfdec_delete(&b);+    return ret;+}++int bfdec_add_si(bfdec_t *r, const bfdec_t *a, int64_t b1, limb_t prec,+                 bf_flags_t flags)+{+    bfdec_t b;+    int ret;+    +    bfdec_init(r->ctx, &b);+    ret = bfdec_set_si(&b, b1);+    ret |= bfdec_add(r, a, &b, prec, flags);+    bfdec_delete(&b);+    return ret;+}++static int __bfdec_div(bfdec_t *r, const bfdec_t *a, const bfdec_t *b,+                       limb_t prec, bf_flags_t flags)+{+    int ret, r_sign;+    limb_t n, nb, precl;+    +    r_sign = a->sign ^ b->sign;+    if (a->expn >= BF_EXP_INF || b->expn >= BF_EXP_INF) {+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bfdec_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF && b->expn == BF_EXP_INF) {+            bfdec_set_nan(r);+            return BF_ST_INVALID_OP;+        } else if (a->expn == BF_EXP_INF) {+            bfdec_set_inf(r, r_sign);+            return 0;+        } else {+            bfdec_set_zero(r, r_sign);+            return 0;+        }+    } else if (a->expn == BF_EXP_ZERO) {+        if (b->expn == BF_EXP_ZERO) {+            bfdec_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bfdec_set_zero(r, r_sign);+            return 0;+        }+    } else if (b->expn == BF_EXP_ZERO) {+        bfdec_set_inf(r, r_sign);+        return BF_ST_DIVIDE_ZERO;+    }++    nb = b->len;+    if (prec == BF_PREC_INF) {+        /* infinite precision: return BF_ST_INVALID_OP if not an exact+           result */+        /* XXX: check */+        precl = nb + 1;+    } else if (flags & BF_FLAG_RADPNT_PREC) {+        /* number of digits after the decimal point */+        /* XXX: check (2 extra digits for rounding + 2 digits) */+        precl = (bf_max(a->expn - b->expn, 0) + 2 ++                 prec + 2 + LIMB_DIGITS - 1) / LIMB_DIGITS;+    } else {+        /* number of limbs of the quotient (2 extra digits for rounding) */+        precl = (prec + 2 + LIMB_DIGITS - 1) / LIMB_DIGITS;+    }+    n = bf_max(a->len, precl);+    +    {+        limb_t *taba, na, i;+        slimb_t d;+        +        na = n + nb;+        taba = bf_malloc(r->ctx, (na + 1) * sizeof(limb_t));+        if (!taba)+            goto fail;+        d = na - a->len;+        memset(taba, 0, d * sizeof(limb_t));+        memcpy(taba + d, a->tab, a->len * sizeof(limb_t));+        if (bfdec_resize(r, n + 1))+            goto fail1;+        if (mp_div_dec(r->ctx, r->tab, taba, na, b->tab, nb)) {+        fail1:+            bf_free(r->ctx, taba);+            goto fail;+        }+        /* see if non zero remainder */+        for(i = 0; i < nb; i++) {+            if (taba[i] != 0)+                break;+        }+        bf_free(r->ctx, taba);+        if (i != nb) {+            if (prec == BF_PREC_INF) {+                bfdec_set_nan(r);+                return BF_ST_INVALID_OP;+            } else {+                r->tab[0] |= 1;+            }+        }+        r->expn = a->expn - b->expn + LIMB_DIGITS;+        r->sign = r_sign;+        ret = bfdec_normalize_and_round(r, prec, flags);+    }+    return ret;+ fail:+    bfdec_set_nan(r);+    return BF_ST_MEM_ERROR;+}++int bfdec_div(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+              bf_flags_t flags)+{+    return bf_op2((bf_t *)r, (bf_t *)a, (bf_t *)b, prec, flags,+                  (bf_op2_func_t *)__bfdec_div);+}++/* a and b must be finite numbers with a >= 0 and b > 0. 'q' is the+   integer defined as floor(a/b) and r = a - q * b. */+static void bfdec_tdivremu(bf_context_t *s, bfdec_t *q, bfdec_t *r,+                           const bfdec_t *a, const bfdec_t *b)+{+    if (bfdec_cmpu(a, b) < 0) {+        bfdec_set_ui(q, 0);+        bfdec_set(r, a);+    } else {+        bfdec_div(q, a, b, 0, BF_RNDZ | BF_FLAG_RADPNT_PREC);+        bfdec_mul(r, q, b, BF_PREC_INF, BF_RNDZ);+        bfdec_sub(r, a, r, BF_PREC_INF, BF_RNDZ);+    }+}++/* division and remainder. +   +   rnd_mode is the rounding mode for the quotient. The additional+   rounding mode BF_RND_EUCLIDIAN is supported.++   'q' is an integer. 'r' is rounded with prec and flags (prec can be+   BF_PREC_INF).+*/+int bfdec_divrem(bfdec_t *q, bfdec_t *r, const bfdec_t *a, const bfdec_t *b,+                 limb_t prec, bf_flags_t flags, int rnd_mode)+{+    bf_context_t *s = q->ctx;+    bfdec_t a1_s, *a1 = &a1_s;+    bfdec_t b1_s, *b1 = &b1_s;+    bfdec_t r1_s, *r1 = &r1_s;+    int q_sign, res;+    BOOL is_ceil, is_rndn;+    +    assert(q != a && q != b);+    assert(r != a && r != b);+    assert(q != r);+    +    if (a->len == 0 || b->len == 0) {+        bfdec_set_zero(q, 0);+        if (a->expn == BF_EXP_NAN || b->expn == BF_EXP_NAN) {+            bfdec_set_nan(r);+            return 0;+        } else if (a->expn == BF_EXP_INF || b->expn == BF_EXP_ZERO) {+            bfdec_set_nan(r);+            return BF_ST_INVALID_OP;+        } else {+            bfdec_set(r, a);+            return bfdec_round(r, prec, flags);+        }+    }++    q_sign = a->sign ^ b->sign;+    is_rndn = (rnd_mode == BF_RNDN || rnd_mode == BF_RNDNA);+    switch(rnd_mode) {+    default:+    case BF_RNDZ:+    case BF_RNDN:+    case BF_RNDNA:+        is_ceil = FALSE;+        break;+    case BF_RNDD:+        is_ceil = q_sign;+        break;+    case BF_RNDU:+        is_ceil = q_sign ^ 1;+        break;+    case BF_RNDA:+        is_ceil = TRUE;+        break;+    case BF_DIVREM_EUCLIDIAN:+        is_ceil = a->sign;+        break;+    }++    a1->expn = a->expn;+    a1->tab = a->tab;+    a1->len = a->len;+    a1->sign = 0;+    +    b1->expn = b->expn;+    b1->tab = b->tab;+    b1->len = b->len;+    b1->sign = 0;++    //    bfdec_print_str("a1", a1);+    //    bfdec_print_str("b1", b1);+    /* XXX: could improve to avoid having a large 'q' */+    bfdec_tdivremu(s, q, r, a1, b1);+    if (bfdec_is_nan(q) || bfdec_is_nan(r))+        goto fail;+    //    bfdec_print_str("q", q);+    //    bfdec_print_str("r", r);+    +    if (r->len != 0) {+        if (is_rndn) {+            bfdec_init(s, r1);+            if (bfdec_set(r1, r))+                goto fail;+            if (bfdec_mul_si(r1, r1, 2, BF_PREC_INF, BF_RNDZ)) {+                bfdec_delete(r1);+                goto fail;+            }+            res = bfdec_cmpu(r1, b);+            bfdec_delete(r1);+            if (res > 0 ||+                (res == 0 &&+                 (rnd_mode == BF_RNDNA ||+                  (get_digit(q->tab, q->len, q->len * LIMB_DIGITS - q->expn) & 1) != 0))) {+                goto do_sub_r;+            }+        } else if (is_ceil) {+        do_sub_r:+            res = bfdec_add_si(q, q, 1, BF_PREC_INF, BF_RNDZ);+            res |= bfdec_sub(r, r, b1, BF_PREC_INF, BF_RNDZ);+            if (res & BF_ST_MEM_ERROR)+                goto fail;+        }+    }++    r->sign ^= a->sign;+    q->sign = q_sign;+    return bfdec_round(r, prec, flags);+ fail:+    bfdec_set_nan(q);+    bfdec_set_nan(r);+    return BF_ST_MEM_ERROR;+}++int bfdec_rem(bfdec_t *r, const bfdec_t *a, const bfdec_t *b, limb_t prec,+              bf_flags_t flags, int rnd_mode)+{+    bfdec_t q_s, *q = &q_s;+    int ret;+    +    bfdec_init(r->ctx, q);+    ret = bfdec_divrem(q, r, a, b, prec, flags, rnd_mode);+    bfdec_delete(q);+    return ret;+}++/* convert to integer (infinite precision) */+int bfdec_rint(bfdec_t *r, int rnd_mode)+{+    return bfdec_round(r, 0, rnd_mode | BF_FLAG_RADPNT_PREC);+}++int bfdec_sqrt(bfdec_t *r, const bfdec_t *a, limb_t prec, bf_flags_t flags)+{+    bf_context_t *s = a->ctx;+    int ret, k;+    limb_t *a1, v;+    slimb_t n, n1, prec1;+    limb_t res;++    assert(r != a);++    if (a->len == 0) {+        if (a->expn == BF_EXP_NAN) {+            bfdec_set_nan(r);+        } else if (a->expn == BF_EXP_INF && a->sign) {+            goto invalid_op;+        } else {+            bfdec_set(r, a);+        }+        ret = 0;+    } else if (a->sign || prec == BF_PREC_INF) {+ invalid_op:+        bfdec_set_nan(r);+        ret = BF_ST_INVALID_OP;+    } else {+        if (flags & BF_FLAG_RADPNT_PREC) {+            prec1 = bf_max(floor_div(a->expn + 1, 2) + prec, 1);+        } else {+            prec1 = prec;+        }+        /* convert the mantissa to an integer with at least 2 *+           prec + 4 digits */+        n = (2 * (prec1 + 2) + 2 * LIMB_DIGITS - 1) / (2 * LIMB_DIGITS);+        if (bfdec_resize(r, n))+            goto fail;+        a1 = bf_malloc(s, sizeof(limb_t) * 2 * n);+        if (!a1)+            goto fail;+        n1 = bf_min(2 * n, a->len);+        memset(a1, 0, (2 * n - n1) * sizeof(limb_t));+        memcpy(a1 + 2 * n - n1, a->tab + a->len - n1, n1 * sizeof(limb_t));+        if (a->expn & 1) {+            res = mp_shr_dec(a1, a1, 2 * n, 1, 0);+        } else {+            res = 0;+        }+        /* normalize so that a1 >= B^(2*n)/4. Not need for n = 1+           because mp_sqrtrem2_dec already does it */+        k = 0;+        if (n > 1) {+            v = a1[2 * n - 1];+            while (v < BF_DEC_BASE / 4) {+                k++;+                v *= 4;+            }+            if (k != 0)+                mp_mul1_dec(a1, a1, 2 * n, 1 << (2 * k), 0);+        }+        if (mp_sqrtrem_dec(s, r->tab, a1, n)) {+            bf_free(s, a1);+            goto fail;+        }+        if (k != 0)+            mp_div1_dec(r->tab, r->tab, n, 1 << k, 0);+        if (!res) {+            res = mp_scan_nz(a1, n + 1);+        }+        bf_free(s, a1);+        if (!res) {+            res = mp_scan_nz(a->tab, a->len - n1);+        }+        if (res != 0)+            r->tab[0] |= 1;+        r->sign = 0;+        r->expn = (a->expn + 1) >> 1;+        ret = bfdec_round(r, prec, flags);+    }+    return ret;+ fail:+    bfdec_set_nan(r);+    return BF_ST_MEM_ERROR;+}++/* The rounding mode is always BF_RNDZ. Return BF_ST_OVERFLOW if there+   is an overflow and 0 otherwise. No memory error is possible. */+int bfdec_get_int32(int *pres, const bfdec_t *a)+{+    uint32_t v;+    int ret;+    if (a->expn >= BF_EXP_INF) {+        ret = 0;+        if (a->expn == BF_EXP_INF) {+            v = (uint32_t)INT32_MAX + a->sign;+             /* XXX: return overflow ? */+        } else {+            v = INT32_MAX;+        }+    } else if (a->expn <= 0) {+        v = 0;+        ret = 0;+    } else if (a->expn <= 9) {+        v = fast_shr_dec(a->tab[a->len - 1], LIMB_DIGITS - a->expn);+        if (a->sign)+            v = -v;+        ret = 0;+    } else if (a->expn == 10) {+        uint64_t v1;+        uint32_t v_max;+#if LIMB_BITS == 64+        v1 = fast_shr_dec(a->tab[a->len - 1], LIMB_DIGITS - a->expn);+#else+        v1 = (uint64_t)a->tab[a->len - 1] * 10 ++            get_digit(a->tab, a->len, (a->len - 1) * LIMB_DIGITS - 1);+#endif+        v_max = (uint32_t)INT32_MAX + a->sign;+        if (v1 > v_max) {+            v = v_max;+            ret = BF_ST_OVERFLOW;+        } else {+            v = v1;+            if (a->sign)+                v = -v;+            ret = 0;+        }+    } else {+        v = (uint32_t)INT32_MAX + a->sign;+        ret = BF_ST_OVERFLOW;+    }+    *pres = v;+    return ret;+}++/* power to an integer with infinite precision */+int bfdec_pow_ui(bfdec_t *r, const bfdec_t *a, limb_t b)+{+    int ret, n_bits, i;+    +    assert(r != a);+    if (b == 0)+        return bfdec_set_ui(r, 1);+    ret = bfdec_set(r, a);+    n_bits = LIMB_BITS - clz(b);+    for(i = n_bits - 2; i >= 0; i--) {+        ret |= bfdec_mul(r, r, r, BF_PREC_INF, BF_RNDZ);+        if ((b >> i) & 1)+            ret |= bfdec_mul(r, r, a, BF_PREC_INF, BF_RNDZ);+    }+    return ret;+}++char *bfdec_ftoa(size_t *plen, const bfdec_t *a, limb_t prec, bf_flags_t flags)+{+    return bf_ftoa_internal(plen, (const bf_t *)a, 10, prec, flags, TRUE);+}++int bfdec_atof(bfdec_t *r, const char *str, const char **pnext,+               limb_t prec, bf_flags_t flags)+{+    slimb_t dummy_exp;+    return bf_atof_internal((bf_t *)r, &dummy_exp, str, pnext, 10, prec,+                            flags, TRUE);+}++#endif /* USE_BF_DEC */++#ifdef USE_FFT_MUL+/***************************************************************/+/* Integer multiplication with FFT */++/* or LIMB_BITS at bit position 'pos' in tab */+static inline void put_bits(limb_t *tab, limb_t len, slimb_t pos, limb_t val)+{+    limb_t i;+    int p;++    i = pos >> LIMB_LOG2_BITS;+    p = pos & (LIMB_BITS - 1);+    if (i < len)+        tab[i] |= val << p;+    if (p != 0) {+        i++;+        if (i < len) {+            tab[i] |= val >> (LIMB_BITS - p);+        }+    }+}++#if defined(__AVX2__)++typedef double NTTLimb;++/* we must have: modulo >= 1 << NTT_MOD_LOG2_MIN */+#define NTT_MOD_LOG2_MIN 50+#define NTT_MOD_LOG2_MAX 51+#define NB_MODS 5+#define NTT_PROOT_2EXP 39+static const int ntt_int_bits[NB_MODS] = { 254, 203, 152, 101, 50, };++static const limb_t ntt_mods[NB_MODS] = { 0x00073a8000000001, 0x0007858000000001, 0x0007a38000000001, 0x0007a68000000001, 0x0007fd8000000001,+};++static const limb_t ntt_proot[2][NB_MODS] = {+    { 0x00056198d44332c8, 0x0002eb5d640aad39, 0x00047e31eaa35fd0, 0x0005271ac118a150, 0x00075e0ce8442bd5, },+    { 0x000461169761bcc5, 0x0002dac3cb2da688, 0x0004abc97751e3bf, 0x000656778fc8c485, 0x0000dc6469c269fa, },+};++static const limb_t ntt_mods_cr[NB_MODS * (NB_MODS - 1) / 2] = {+ 0x00020e4da740da8e, 0x0004c3dc09c09c1d, 0x000063bd097b4271, 0x000799d8f18f18fd,+ 0x0005384222222264, 0x000572b07c1f07fe, 0x00035cd08888889a,+ 0x00066015555557e3, 0x000725960b60b623,+ 0x0002fc1fa1d6ce12,+};++#else++typedef limb_t NTTLimb;++#if LIMB_BITS == 64++#define NTT_MOD_LOG2_MIN 61+#define NTT_MOD_LOG2_MAX 62+#define NB_MODS 5+#define NTT_PROOT_2EXP 51+static const int ntt_int_bits[NB_MODS] = { 307, 246, 185, 123, 61, };++static const limb_t ntt_mods[NB_MODS] = { 0x28d8000000000001, 0x2a88000000000001, 0x2ed8000000000001, 0x3508000000000001, 0x3aa8000000000001,+};++static const limb_t ntt_proot[2][NB_MODS] = {+    { 0x1b8ea61034a2bea7, 0x21a9762de58206fb, 0x02ca782f0756a8ea, 0x278384537a3e50a1, 0x106e13fee74ce0ab, },+    { 0x233513af133e13b8, 0x1d13140d1c6f75f1, 0x12cde57f97e3eeda, 0x0d6149e23cbe654f, 0x36cd204f522a1379, },+};++static const limb_t ntt_mods_cr[NB_MODS * (NB_MODS - 1) / 2] = {+ 0x08a9ed097b425eea, 0x18a44aaaaaaaaab3, 0x2493f57f57f57f5d, 0x126b8d0649a7f8d4,+ 0x09d80ed7303b5ccc, 0x25b8bcf3cf3cf3d5, 0x2ce6ce63398ce638,+ 0x0e31fad40a57eb59, 0x02a3529fd4a7f52f,+ 0x3a5493e93e93e94a,+};++#elif LIMB_BITS == 32++/* we must have: modulo >= 1 << NTT_MOD_LOG2_MIN */+#define NTT_MOD_LOG2_MIN 29+#define NTT_MOD_LOG2_MAX 30+#define NB_MODS 5+#define NTT_PROOT_2EXP 20+static const int ntt_int_bits[NB_MODS] = { 148, 119, 89, 59, 29, };++static const limb_t ntt_mods[NB_MODS] = { 0x0000000032b00001, 0x0000000033700001, 0x0000000036d00001, 0x0000000037300001, 0x000000003e500001,+};++static const limb_t ntt_proot[2][NB_MODS] = {+    { 0x0000000032525f31, 0x0000000005eb3b37, 0x00000000246eda9f, 0x0000000035f25901, 0x00000000022f5768, },+    { 0x00000000051eba1a, 0x00000000107be10e, 0x000000001cd574e0, 0x00000000053806e6, 0x000000002cd6bf98, },+};++static const limb_t ntt_mods_cr[NB_MODS * (NB_MODS - 1) / 2] = {+ 0x000000000449559a, 0x000000001eba6ca9, 0x000000002ec18e46, 0x000000000860160b,+ 0x000000000d321307, 0x000000000bf51120, 0x000000000f662938,+ 0x000000000932ab3e, 0x000000002f40eef8,+ 0x000000002e760905,+};++#endif /* LIMB_BITS */++#endif /* !AVX2 */++#if defined(__AVX2__)+#define NTT_TRIG_K_MAX 18+#else+#define NTT_TRIG_K_MAX 19+#endif++typedef struct BFNTTState {+    bf_context_t *ctx;+    +    /* used for mul_mod_fast() */+    limb_t ntt_mods_div[NB_MODS];++    limb_t ntt_proot_pow[NB_MODS][2][NTT_PROOT_2EXP + 1];+    limb_t ntt_proot_pow_inv[NB_MODS][2][NTT_PROOT_2EXP + 1];+    NTTLimb *ntt_trig[NB_MODS][2][NTT_TRIG_K_MAX + 1];+    /* 1/2^n mod m */+    limb_t ntt_len_inv[NB_MODS][NTT_PROOT_2EXP + 1][2];+#if defined(__AVX2__)+    __m256d ntt_mods_cr_vec[NB_MODS * (NB_MODS - 1) / 2];+    __m256d ntt_mods_vec[NB_MODS];+    __m256d ntt_mods_inv_vec[NB_MODS];+#else+    limb_t ntt_mods_cr_inv[NB_MODS * (NB_MODS - 1) / 2];+#endif+} BFNTTState;++static NTTLimb *get_trig(BFNTTState *s, int k, int inverse, int m_idx);++/* add modulo with up to (LIMB_BITS-1) bit modulo */+static inline limb_t add_mod(limb_t a, limb_t b, limb_t m)+{+    limb_t r;+    r = a + b;+    if (r >= m)+        r -= m;+    return r;+}++/* sub modulo with up to LIMB_BITS bit modulo */+static inline limb_t sub_mod(limb_t a, limb_t b, limb_t m)+{+    limb_t r;+    r = a - b;+    if (r > a)+        r += m;+    return r;+}++/* return (r0+r1*B) mod m +   precondition: 0 <= r0+r1*B < 2^(64+NTT_MOD_LOG2_MIN) +*/+static inline limb_t mod_fast(dlimb_t r, +                                limb_t m, limb_t m_inv)+{+    limb_t a1, q, t0, r1, r0;+    +    a1 = r >> NTT_MOD_LOG2_MIN;+    +    q = ((dlimb_t)a1 * m_inv) >> LIMB_BITS;+    r = r - (dlimb_t)q * m - m * 2;+    r1 = r >> LIMB_BITS;+    t0 = (slimb_t)r1 >> 1;+    r += m & t0;+    r0 = r;+    r1 = r >> LIMB_BITS;+    r0 += m & r1;+    return r0;+}++/* faster version using precomputed modulo inverse. +   precondition: 0 <= a * b < 2^(64+NTT_MOD_LOG2_MIN) */+static inline limb_t mul_mod_fast(limb_t a, limb_t b, +                                    limb_t m, limb_t m_inv)+{+    dlimb_t r;+    r = (dlimb_t)a * (dlimb_t)b;+    return mod_fast(r, m, m_inv);+}++static inline limb_t init_mul_mod_fast(limb_t m)+{+    dlimb_t t;+    assert(m < (limb_t)1 << NTT_MOD_LOG2_MAX);+    assert(m >= (limb_t)1 << NTT_MOD_LOG2_MIN);+    t = (dlimb_t)1 << (LIMB_BITS + NTT_MOD_LOG2_MIN);+    return t / m;+}++/* Faster version used when the multiplier is constant. 0 <= a < 2^64,+   0 <= b < m. */+static inline limb_t mul_mod_fast2(limb_t a, limb_t b, +                                     limb_t m, limb_t b_inv)+{+    limb_t r, q;++    q = ((dlimb_t)a * (dlimb_t)b_inv) >> LIMB_BITS;+    r = a * b - q * m;+    if (r >= m)+        r -= m;+    return r;+}++/* Faster version used when the multiplier is constant. 0 <= a < 2^64,+   0 <= b < m. Let r = a * b mod m. The return value is 'r' or 'r ++   m'. */+static inline limb_t mul_mod_fast3(limb_t a, limb_t b, +                                     limb_t m, limb_t b_inv)+{+    limb_t r, q;++    q = ((dlimb_t)a * (dlimb_t)b_inv) >> LIMB_BITS;+    r = a * b - q * m;+    return r;+}++static inline limb_t init_mul_mod_fast2(limb_t b, limb_t m)+{+    return ((dlimb_t)b << LIMB_BITS) / m;+}++#ifdef __AVX2__++static inline limb_t ntt_limb_to_int(NTTLimb a, limb_t m)+{+    slimb_t v;+    v = a;+    if (v < 0)+        v += m;+    if (v >= m)+        v -= m;+    return v;+}++static inline NTTLimb int_to_ntt_limb(limb_t a, limb_t m)+{+    return (slimb_t)a;+}++static inline NTTLimb int_to_ntt_limb2(limb_t a, limb_t m)+{+    if (a >= (m / 2))+        a -= m;+    return (slimb_t)a;+}++/* return r + m if r < 0 otherwise r. */+static inline __m256d ntt_mod1(__m256d r, __m256d m)+{+    return _mm256_blendv_pd(r, r + m, r);+}++/* input: abs(r) < 2 * m. Output: abs(r) < m */+static inline __m256d ntt_mod(__m256d r, __m256d mf, __m256d m2f)+{+    return _mm256_blendv_pd(r, r + m2f, r) - mf;+}++/* input: abs(a*b) < 2 * m^2, output: abs(r) < m */+static inline __m256d ntt_mul_mod(__m256d a, __m256d b, __m256d mf,+                                  __m256d m_inv)+{+    __m256d r, q, ab1, ab0, qm0, qm1;+    ab1 = a * b;+    q = _mm256_round_pd(ab1 * m_inv, 0); /* round to nearest */+    qm1 = q * mf;+    qm0 = _mm256_fmsub_pd(q, mf, qm1); /* low part */+    ab0 = _mm256_fmsub_pd(a, b, ab1); /* low part */+    r = (ab1 - qm1) + (ab0 - qm0);+    return r;+}++static void *bf_aligned_malloc(bf_context_t *s, size_t size, size_t align)+{+    void *ptr;+    void **ptr1;+    ptr = bf_malloc(s, size + sizeof(void *) + align - 1);+    if (!ptr)+        return NULL;+    ptr1 = (void **)(((uintptr_t)ptr + sizeof(void *) + align - 1) &+                     ~(align - 1));+    ptr1[-1] = ptr;+    return ptr1;+}++static void bf_aligned_free(bf_context_t *s, void *ptr)+{+    if (!ptr)+        return;+    bf_free(s, ((void **)ptr)[-1]);+}++static void *ntt_malloc(BFNTTState *s, size_t size)+{+    return bf_aligned_malloc(s->ctx, size, 64);+}++static void ntt_free(BFNTTState *s, void *ptr)+{+    bf_aligned_free(s->ctx, ptr);+}++static no_inline int ntt_fft(BFNTTState *s,+                             NTTLimb *out_buf, NTTLimb *in_buf,+                             NTTLimb *tmp_buf, int fft_len_log2,+                             int inverse, int m_idx)+{+    limb_t nb_blocks, fft_per_block, p, k, n, stride_in, i, j;+    NTTLimb *tab_in, *tab_out, *tmp, *trig;+    __m256d m_inv, mf, m2f, c, a0, a1, b0, b1;+    limb_t m;+    int l;+    +    m = ntt_mods[m_idx];+    +    m_inv = _mm256_set1_pd(1.0 / (double)m);+    mf = _mm256_set1_pd(m);+    m2f = _mm256_set1_pd(m * 2);++    n = (limb_t)1 << fft_len_log2;+    assert(n >= 8);+    stride_in = n / 2;++    tab_in = in_buf;+    tab_out = tmp_buf;+    trig = get_trig(s, fft_len_log2, inverse, m_idx);+    if (!trig)+        return -1;+    p = 0;+    for(k = 0; k < stride_in; k += 4) {+        a0 = _mm256_load_pd(&tab_in[k]);+        a1 = _mm256_load_pd(&tab_in[k + stride_in]);+        c = _mm256_load_pd(trig);+        trig += 4;+        b0 = ntt_mod(a0 + a1, mf, m2f);+        b1 = ntt_mul_mod(a0 - a1, c, mf, m_inv);+        a0 = _mm256_permute2f128_pd(b0, b1, 0x20);+        a1 = _mm256_permute2f128_pd(b0, b1, 0x31);+        a0 = _mm256_permute4x64_pd(a0, 0xd8);+        a1 = _mm256_permute4x64_pd(a1, 0xd8);+        _mm256_store_pd(&tab_out[p], a0);+        _mm256_store_pd(&tab_out[p + 4], a1);+        p += 2 * 4;+    }+    tmp = tab_in;+    tab_in = tab_out;+    tab_out = tmp;++    trig = get_trig(s, fft_len_log2 - 1, inverse, m_idx);+    if (!trig)+        return -1;+    p = 0;+    for(k = 0; k < stride_in; k += 4) {+        a0 = _mm256_load_pd(&tab_in[k]);+        a1 = _mm256_load_pd(&tab_in[k + stride_in]);+        c = _mm256_setr_pd(trig[0], trig[0], trig[1], trig[1]);+        trig += 2;+        b0 = ntt_mod(a0 + a1, mf, m2f);+        b1 = ntt_mul_mod(a0 - a1, c, mf, m_inv);+        a0 = _mm256_permute2f128_pd(b0, b1, 0x20);+        a1 = _mm256_permute2f128_pd(b0, b1, 0x31);+        _mm256_store_pd(&tab_out[p], a0);+        _mm256_store_pd(&tab_out[p + 4], a1);+        p += 2 * 4;+    }+    tmp = tab_in;+    tab_in = tab_out;+    tab_out = tmp;+    +    nb_blocks = n / 4;+    fft_per_block = 4;++    l = fft_len_log2 - 2;+    while (nb_blocks != 2) {+        nb_blocks >>= 1;+        p = 0;+        k = 0;+        trig = get_trig(s, l, inverse, m_idx);+        if (!trig)+            return -1;+        for(i = 0; i < nb_blocks; i++) {+            c = _mm256_set1_pd(trig[0]);+            trig++;+            for(j = 0; j < fft_per_block; j += 4) {+                a0 = _mm256_load_pd(&tab_in[k + j]);+                a1 = _mm256_load_pd(&tab_in[k + j + stride_in]);+                b0 = ntt_mod(a0 + a1, mf, m2f);+                b1 = ntt_mul_mod(a0 - a1, c, mf, m_inv);+                _mm256_store_pd(&tab_out[p + j], b0);+                _mm256_store_pd(&tab_out[p + j + fft_per_block], b1);+            }+            k += fft_per_block;+            p += 2 * fft_per_block;+        }+        fft_per_block <<= 1;+        l--;+        tmp = tab_in;+        tab_in = tab_out;+        tab_out = tmp;+    }++    tab_out = out_buf;+    for(k = 0; k < stride_in; k += 4) {+        a0 = _mm256_load_pd(&tab_in[k]);+        a1 = _mm256_load_pd(&tab_in[k + stride_in]);+        b0 = ntt_mod(a0 + a1, mf, m2f);+        b1 = ntt_mod(a0 - a1, mf, m2f);+        _mm256_store_pd(&tab_out[k], b0);+        _mm256_store_pd(&tab_out[k + stride_in], b1);+    }+    return 0;+}++static void ntt_vec_mul(BFNTTState *s,+                        NTTLimb *tab1, NTTLimb *tab2, limb_t fft_len_log2,+                        int k_tot, int m_idx)+{+    limb_t i, c_inv, n, m;+    __m256d m_inv, mf, a, b, c;+    +    m = ntt_mods[m_idx];+    c_inv = s->ntt_len_inv[m_idx][k_tot][0];+    m_inv = _mm256_set1_pd(1.0 / (double)m);+    mf = _mm256_set1_pd(m);+    c = _mm256_set1_pd(int_to_ntt_limb(c_inv, m));+    n = (limb_t)1 << fft_len_log2;+    for(i = 0; i < n; i += 4) {+        a = _mm256_load_pd(&tab1[i]);+        b = _mm256_load_pd(&tab2[i]);+        a = ntt_mul_mod(a, b, mf, m_inv);+        a = ntt_mul_mod(a, c, mf, m_inv);+        _mm256_store_pd(&tab1[i], a);+    }+}++static no_inline void mul_trig(NTTLimb *buf,+                               limb_t n, limb_t c1, limb_t m, limb_t m_inv1)+{+    limb_t i, c2, c3, c4;+    __m256d c, c_mul, a0, mf, m_inv;+    assert(n >= 2);+    +    mf = _mm256_set1_pd(m);+    m_inv = _mm256_set1_pd(1.0 / (double)m);++    c2 = mul_mod_fast(c1, c1, m, m_inv1);+    c3 = mul_mod_fast(c2, c1, m, m_inv1);+    c4 = mul_mod_fast(c2, c2, m, m_inv1);+    c = _mm256_setr_pd(1, int_to_ntt_limb(c1, m),+                       int_to_ntt_limb(c2, m), int_to_ntt_limb(c3, m));+    c_mul = _mm256_set1_pd(int_to_ntt_limb(c4, m));+    for(i = 0; i < n; i += 4) {+        a0 = _mm256_load_pd(&buf[i]);+        a0 = ntt_mul_mod(a0, c, mf, m_inv);+        _mm256_store_pd(&buf[i], a0);+        c = ntt_mul_mod(c, c_mul, mf, m_inv);+    }+}++#else++static void *ntt_malloc(BFNTTState *s, size_t size)+{+    return bf_malloc(s->ctx, size);+}++static void ntt_free(BFNTTState *s, void *ptr)+{+    bf_free(s->ctx, ptr);+}++static inline limb_t ntt_limb_to_int(NTTLimb a, limb_t m)+{+    if (a >= m)+        a -= m;+    return a;+}++static inline NTTLimb int_to_ntt_limb(slimb_t a, limb_t m)+{+    return a;+}++static no_inline int ntt_fft(BFNTTState *s, NTTLimb *out_buf, NTTLimb *in_buf,+                             NTTLimb *tmp_buf, int fft_len_log2,+                             int inverse, int m_idx)+{+    limb_t nb_blocks, fft_per_block, p, k, n, stride_in, i, j, m, m2;+    NTTLimb *tab_in, *tab_out, *tmp, a0, a1, b0, b1, c, *trig, c_inv;+    int l;+    +    m = ntt_mods[m_idx];+    m2 = 2 * m;+    n = (limb_t)1 << fft_len_log2;+    nb_blocks = n;+    fft_per_block = 1;+    stride_in = n / 2;+    tab_in = in_buf;+    tab_out = tmp_buf;+    l = fft_len_log2;+    while (nb_blocks != 2) {+        nb_blocks >>= 1;+        p = 0;+        k = 0;+        trig = get_trig(s, l, inverse, m_idx);+        if (!trig)+            return -1;+        for(i = 0; i < nb_blocks; i++) {+            c = trig[0];+            c_inv = trig[1];+            trig += 2;+            for(j = 0; j < fft_per_block; j++) {+                a0 = tab_in[k + j];+                a1 = tab_in[k + j + stride_in];+                b0 = add_mod(a0, a1, m2);+                b1 = a0 - a1 + m2;+                b1 = mul_mod_fast3(b1, c, m, c_inv);+                tab_out[p + j] = b0;+                tab_out[p + j + fft_per_block] = b1;+            }+            k += fft_per_block;+            p += 2 * fft_per_block;+        }+        fft_per_block <<= 1;+        l--;+        tmp = tab_in;+        tab_in = tab_out;+        tab_out = tmp;+    }+    /* no twiddle in last step */+    tab_out = out_buf; +    for(k = 0; k < stride_in; k++) {+        a0 = tab_in[k];+        a1 = tab_in[k + stride_in];+        b0 = add_mod(a0, a1, m2);+        b1 = sub_mod(a0, a1, m2);+        tab_out[k] = b0;+        tab_out[k + stride_in] = b1;+    }+    return 0;+}++static void ntt_vec_mul(BFNTTState *s,+                        NTTLimb *tab1, NTTLimb *tab2, int fft_len_log2,+                        int k_tot, int m_idx)+{+    limb_t i, norm, norm_inv, a, n, m, m_inv;+    +    m = ntt_mods[m_idx];+    m_inv = s->ntt_mods_div[m_idx];+    norm = s->ntt_len_inv[m_idx][k_tot][0];+    norm_inv = s->ntt_len_inv[m_idx][k_tot][1];+    n = (limb_t)1 << fft_len_log2;+    for(i = 0; i < n; i++) {+        a = tab1[i];+        /* need to reduce the range so that the product is <+           2^(LIMB_BITS+NTT_MOD_LOG2_MIN) */+        if (a >= m)+            a -= m;+        a = mul_mod_fast(a, tab2[i], m, m_inv);+        a = mul_mod_fast3(a, norm, m, norm_inv);+        tab1[i] = a;+    }+}++static no_inline void mul_trig(NTTLimb *buf,+                               limb_t n, limb_t c_mul, limb_t m, limb_t m_inv)+{+    limb_t i, c0, c_mul_inv;+    +    c0 = 1;+    c_mul_inv = init_mul_mod_fast2(c_mul, m);+    for(i = 0; i < n; i++) {+        buf[i] = mul_mod_fast(buf[i], c0, m, m_inv);+        c0 = mul_mod_fast2(c0, c_mul, m, c_mul_inv);+    }+}++#endif /* !AVX2 */++static no_inline NTTLimb *get_trig(BFNTTState *s,+                                   int k, int inverse, int m_idx)+{+    NTTLimb *tab;+    limb_t i, n2, c, c_mul, m, c_mul_inv;+    +    if (k > NTT_TRIG_K_MAX)+        return NULL;++    tab = s->ntt_trig[m_idx][inverse][k];+    if (tab)+        return tab;+    n2 = (limb_t)1 << (k - 1);+    m = ntt_mods[m_idx];+#ifdef __AVX2__+    tab = ntt_malloc(s, sizeof(NTTLimb) * n2);+#else+    tab = ntt_malloc(s, sizeof(NTTLimb) * n2 * 2);+#endif+    if (!tab)+        return NULL;+    c = 1;+    c_mul = s->ntt_proot_pow[m_idx][inverse][k];+    c_mul_inv = s->ntt_proot_pow_inv[m_idx][inverse][k];+    for(i = 0; i < n2; i++) {+#ifdef __AVX2__+        tab[i] = int_to_ntt_limb2(c, m);+#else+        tab[2 * i] = int_to_ntt_limb(c, m);+        tab[2 * i + 1] = init_mul_mod_fast2(c, m);+#endif+        c = mul_mod_fast2(c, c_mul, m, c_mul_inv);+    }+    s->ntt_trig[m_idx][inverse][k] = tab;+    return tab;+}++void fft_clear_cache(bf_context_t *s1)+{+    int m_idx, inverse, k;+    BFNTTState *s = s1->ntt_state;+    if (s) {+        for(m_idx = 0; m_idx < NB_MODS; m_idx++) {+            for(inverse = 0; inverse < 2; inverse++) {+                for(k = 0; k < NTT_TRIG_K_MAX + 1; k++) {+                    if (s->ntt_trig[m_idx][inverse][k]) {+                        ntt_free(s, s->ntt_trig[m_idx][inverse][k]);+                        s->ntt_trig[m_idx][inverse][k] = NULL;+                    }+                }+            }+        }+#if defined(__AVX2__)+        bf_aligned_free(s1, s);+#else+        bf_free(s1, s);+#endif+        s1->ntt_state = NULL;+    }+}++#define STRIP_LEN 16++/* dst = buf1, src = buf2 */+static int ntt_fft_partial(BFNTTState *s, NTTLimb *buf1,+                           int k1, int k2, limb_t n1, limb_t n2, int inverse,+                           limb_t m_idx)+{+    limb_t i, j, c_mul, c0, m, m_inv, strip_len, l;+    NTTLimb *buf2, *buf3;+    +    buf2 = NULL;+    buf3 = ntt_malloc(s, sizeof(NTTLimb) * n1);+    if (!buf3)+        goto fail;+    if (k2 == 0) {+        if (ntt_fft(s, buf1, buf1, buf3, k1, inverse, m_idx))+            goto fail;+    } else {+        strip_len = STRIP_LEN;+        buf2 = ntt_malloc(s, sizeof(NTTLimb) * n1 * strip_len);+        if (!buf2)+            goto fail;+        m = ntt_mods[m_idx];+        m_inv = s->ntt_mods_div[m_idx];+        c0 = s->ntt_proot_pow[m_idx][inverse][k1 + k2];+        c_mul = 1;+        assert((n2 % strip_len) == 0);+        for(j = 0; j < n2; j += strip_len) {+            for(i = 0; i < n1; i++) {+                for(l = 0; l < strip_len; l++) {+                    buf2[i + l * n1] = buf1[i * n2 + (j + l)];+                }+            }+            for(l = 0; l < strip_len; l++) {+                if (inverse)+                    mul_trig(buf2 + l * n1, n1, c_mul, m, m_inv);+                if (ntt_fft(s, buf2 + l * n1, buf2 + l * n1, buf3, k1, inverse, m_idx))+                    goto fail;+                if (!inverse)+                    mul_trig(buf2 + l * n1, n1, c_mul, m, m_inv);+                c_mul = mul_mod_fast(c_mul, c0, m, m_inv);+            }+            +            for(i = 0; i < n1; i++) {+                for(l = 0; l < strip_len; l++) {+                    buf1[i * n2 + (j + l)] = buf2[i + l *n1];+                }+            }+        }+        ntt_free(s, buf2);+    }+    ntt_free(s, buf3);+    return 0;+ fail:+    ntt_free(s, buf2);+    ntt_free(s, buf3);+    return -1;+}+++/* dst = buf1, src = buf2, tmp = buf3 */+static int ntt_conv(BFNTTState *s, NTTLimb *buf1, NTTLimb *buf2,+                    int k, int k_tot, limb_t m_idx)+{+    limb_t n1, n2, i;+    int k1, k2;+    +    if (k <= NTT_TRIG_K_MAX) {+        k1 = k;+    } else {+        /* recursive split of the FFT */+        k1 = bf_min(k / 2, NTT_TRIG_K_MAX);+    }+    k2 = k - k1;+    n1 = (limb_t)1 << k1;+    n2 = (limb_t)1 << k2;+    +    if (ntt_fft_partial(s, buf1, k1, k2, n1, n2, 0, m_idx))+        return -1;+    if (ntt_fft_partial(s, buf2, k1, k2, n1, n2, 0, m_idx))+        return -1;+    if (k2 == 0) {+        ntt_vec_mul(s, buf1, buf2, k, k_tot, m_idx);+    } else {+        for(i = 0; i < n1; i++) {+            ntt_conv(s, buf1 + i * n2, buf2 + i * n2, k2, k_tot, m_idx);+        }+    }+    if (ntt_fft_partial(s, buf1, k1, k2, n1, n2, 1, m_idx))+        return -1;+    return 0;+}+++static no_inline void limb_to_ntt(BFNTTState *s,+                                  NTTLimb *tabr, limb_t fft_len,+                                  const limb_t *taba, limb_t a_len, int dpl,+                                  int first_m_idx, int nb_mods)+{+    slimb_t i, n;+    dlimb_t a, b;+    int j, shift;+    limb_t base_mask1, a0, a1, a2, r, m, m_inv;+    +#if 0+    for(i = 0; i < a_len; i++) {+        printf("%" PRId64 ": " FMT_LIMB "\n",+               (int64_t)i, taba[i]);+    }+#endif   +    memset(tabr, 0, sizeof(NTTLimb) * fft_len * nb_mods);+    shift = dpl & (LIMB_BITS - 1);+    if (shift == 0)+        base_mask1 = -1;+    else+        base_mask1 = ((limb_t)1 << shift) - 1;+    n = bf_min(fft_len, (a_len * LIMB_BITS + dpl - 1) / dpl);+    for(i = 0; i < n; i++) {+        a0 = get_bits(taba, a_len, i * dpl);+        if (dpl <= LIMB_BITS) {+            a0 &= base_mask1;+            a = a0;+        } else {+            a1 = get_bits(taba, a_len, i * dpl + LIMB_BITS);+            if (dpl <= (LIMB_BITS + NTT_MOD_LOG2_MIN)) {+                a = a0 | ((dlimb_t)(a1 & base_mask1) << LIMB_BITS);+            } else {+                if (dpl > 2 * LIMB_BITS) {+                    a2 = get_bits(taba, a_len, i * dpl + LIMB_BITS * 2) &+                        base_mask1;+                } else {+                    a1 &= base_mask1;+                    a2 = 0;+                }+                //            printf("a=0x%016lx%016lx%016lx\n", a2, a1, a0);+                a = (a0 >> (LIMB_BITS - NTT_MOD_LOG2_MAX + NTT_MOD_LOG2_MIN)) |+                    ((dlimb_t)a1 << (NTT_MOD_LOG2_MAX - NTT_MOD_LOG2_MIN)) |+                    ((dlimb_t)a2 << (LIMB_BITS + NTT_MOD_LOG2_MAX - NTT_MOD_LOG2_MIN));+                a0 &= ((limb_t)1 << (LIMB_BITS - NTT_MOD_LOG2_MAX + NTT_MOD_LOG2_MIN)) - 1;+            }+        }+        for(j = 0; j < nb_mods; j++) {+            m = ntt_mods[first_m_idx + j];+            m_inv = s->ntt_mods_div[first_m_idx + j];+            r = mod_fast(a, m, m_inv);+            if (dpl > (LIMB_BITS + NTT_MOD_LOG2_MIN)) {+                b = ((dlimb_t)r << (LIMB_BITS - NTT_MOD_LOG2_MAX + NTT_MOD_LOG2_MIN)) | a0;+                r = mod_fast(b, m, m_inv);+            }+            tabr[i + j * fft_len] = int_to_ntt_limb(r, m);+        }+    }+}++#if defined(__AVX2__)++#define VEC_LEN 4++typedef union {+    __m256d v;+    double d[4];+} VecUnion;++static no_inline void ntt_to_limb(BFNTTState *s, limb_t *tabr, limb_t r_len,+                                  const NTTLimb *buf, int fft_len_log2, int dpl,+                                  int nb_mods)+{+    const limb_t *mods = ntt_mods + NB_MODS - nb_mods;+    const __m256d *mods_cr_vec, *mf, *m_inv;+    VecUnion y[NB_MODS];+    limb_t u[NB_MODS], carry[NB_MODS], fft_len, base_mask1, r;+    slimb_t i, len, pos;+    int j, k, l, shift, n_limb1, p;+    dlimb_t t;+        +    j = NB_MODS * (NB_MODS - 1) / 2 - nb_mods * (nb_mods - 1) / 2;+    mods_cr_vec = s->ntt_mods_cr_vec + j;+    mf = s->ntt_mods_vec + NB_MODS - nb_mods;+    m_inv = s->ntt_mods_inv_vec + NB_MODS - nb_mods;+        +    shift = dpl & (LIMB_BITS - 1);+    if (shift == 0)+        base_mask1 = -1;+    else+        base_mask1 = ((limb_t)1 << shift) - 1;+    n_limb1 = ((unsigned)dpl - 1) / LIMB_BITS;+    for(j = 0; j < NB_MODS; j++) +        carry[j] = 0;+    for(j = 0; j < NB_MODS; j++) +        u[j] = 0; /* avoid warnings */+    memset(tabr, 0, sizeof(limb_t) * r_len);+    fft_len = (limb_t)1 << fft_len_log2;+    len = bf_min(fft_len, (r_len * LIMB_BITS + dpl - 1) / dpl);+    len = (len + VEC_LEN - 1) & ~(VEC_LEN - 1);+    i = 0;+    while (i < len) {+        for(j = 0; j < nb_mods; j++)+            y[j].v = *(__m256d *)&buf[i + fft_len * j];++        /* Chinese remainder to get mixed radix representation */+        l = 0;+        for(j = 0; j < nb_mods - 1; j++) {+            y[j].v = ntt_mod1(y[j].v, mf[j]);+            for(k = j + 1; k < nb_mods; k++) {+                y[k].v = ntt_mul_mod(y[k].v - y[j].v,+                                     mods_cr_vec[l], mf[k], m_inv[k]);+                l++;+            }+        }+        y[j].v = ntt_mod1(y[j].v, mf[j]);+        +        for(p = 0; p < VEC_LEN; p++) {+            /* back to normal representation */+            u[0] = (int64_t)y[nb_mods - 1].d[p];+            l = 1;+            for(j = nb_mods - 2; j >= 1; j--) {+                r = (int64_t)y[j].d[p];+                for(k = 0; k < l; k++) {+                    t = (dlimb_t)u[k] * mods[j] + r;+                    r = t >> LIMB_BITS;+                    u[k] = t;+                }+                u[l] = r;+                l++;+            }+            /* XXX: for nb_mods = 5, l should be 4 */+            +            /* last step adds the carry */+            r = (int64_t)y[0].d[p];+            for(k = 0; k < l; k++) {+                t = (dlimb_t)u[k] * mods[j] + r + carry[k];+                r = t >> LIMB_BITS;+                u[k] = t;+            }+            u[l] = r + carry[l];++#if 0+            printf("%" PRId64 ": ", i);+            for(j = nb_mods - 1; j >= 0; j--) {+                printf(" %019" PRIu64, u[j]);+            }+            printf("\n");+#endif+            +            /* write the digits */+            pos = i * dpl;+            for(j = 0; j < n_limb1; j++) {+                put_bits(tabr, r_len, pos, u[j]);+                pos += LIMB_BITS;+            }+            put_bits(tabr, r_len, pos, u[n_limb1] & base_mask1);+            /* shift by dpl digits and set the carry */+            if (shift == 0) {+                for(j = n_limb1 + 1; j < nb_mods; j++)+                    carry[j - (n_limb1 + 1)] = u[j];+            } else {+                for(j = n_limb1; j < nb_mods - 1; j++) {+                    carry[j - n_limb1] = (u[j] >> shift) |+                        (u[j + 1] << (LIMB_BITS - shift));+                }+                carry[nb_mods - 1 - n_limb1] = u[nb_mods - 1] >> shift;+            }+            i++;+        }+    }+}+#else+static no_inline void ntt_to_limb(BFNTTState *s, limb_t *tabr, limb_t r_len,+                                  const NTTLimb *buf, int fft_len_log2, int dpl,+                                  int nb_mods)+{+    const limb_t *mods = ntt_mods + NB_MODS - nb_mods;+    const limb_t *mods_cr, *mods_cr_inv;+    limb_t y[NB_MODS], u[NB_MODS], carry[NB_MODS], fft_len, base_mask1, r;+    slimb_t i, len, pos;+    int j, k, l, shift, n_limb1;+    dlimb_t t;+        +    j = NB_MODS * (NB_MODS - 1) / 2 - nb_mods * (nb_mods - 1) / 2;+    mods_cr = ntt_mods_cr + j;+    mods_cr_inv = s->ntt_mods_cr_inv + j;++    shift = dpl & (LIMB_BITS - 1);+    if (shift == 0)+        base_mask1 = -1;+    else+        base_mask1 = ((limb_t)1 << shift) - 1;+    n_limb1 = ((unsigned)dpl - 1) / LIMB_BITS;+    for(j = 0; j < NB_MODS; j++) +        carry[j] = 0;+    for(j = 0; j < NB_MODS; j++) +        u[j] = 0; /* avoid warnings */+    memset(tabr, 0, sizeof(limb_t) * r_len);+    fft_len = (limb_t)1 << fft_len_log2;+    len = bf_min(fft_len, (r_len * LIMB_BITS + dpl - 1) / dpl);+    for(i = 0; i < len; i++) {+        for(j = 0; j < nb_mods; j++)  {+            y[j] = ntt_limb_to_int(buf[i + fft_len * j], mods[j]);+        }++        /* Chinese remainder to get mixed radix representation */+        l = 0;+        for(j = 0; j < nb_mods - 1; j++) {+            for(k = j + 1; k < nb_mods; k++) {+                limb_t m;+                m = mods[k];+                /* Note: there is no overflow in the sub_mod() because+                   the modulos are sorted by increasing order */+                y[k] = mul_mod_fast2(y[k] - y[j] + m, +                                     mods_cr[l], m, mods_cr_inv[l]);+                l++;+            }+        }+        +        /* back to normal representation */+        u[0] = y[nb_mods - 1];+        l = 1;+        for(j = nb_mods - 2; j >= 1; j--) {+            r = y[j];+            for(k = 0; k < l; k++) {+                t = (dlimb_t)u[k] * mods[j] + r;+                r = t >> LIMB_BITS;+                u[k] = t;+            }+            u[l] = r;+            l++;+        }+        +        /* last step adds the carry */+        r = y[0];+        for(k = 0; k < l; k++) {+            t = (dlimb_t)u[k] * mods[j] + r + carry[k];+            r = t >> LIMB_BITS;+            u[k] = t;+        }+        u[l] = r + carry[l];++#if 0+        printf("%" PRId64 ": ", (int64_t)i);+        for(j = nb_mods - 1; j >= 0; j--) {+            printf(" " FMT_LIMB, u[j]);+        }+        printf("\n");+#endif+        +        /* write the digits */+        pos = i * dpl;+        for(j = 0; j < n_limb1; j++) {+            put_bits(tabr, r_len, pos, u[j]);+            pos += LIMB_BITS;+        }+        put_bits(tabr, r_len, pos, u[n_limb1] & base_mask1);+        /* shift by dpl digits and set the carry */+        if (shift == 0) {+            for(j = n_limb1 + 1; j < nb_mods; j++)+                carry[j - (n_limb1 + 1)] = u[j];+        } else {+            for(j = n_limb1; j < nb_mods - 1; j++) {+                carry[j - n_limb1] = (u[j] >> shift) |+                    (u[j + 1] << (LIMB_BITS - shift));+            }+            carry[nb_mods - 1 - n_limb1] = u[nb_mods - 1] >> shift;+        }+    }+}+#endif++static int ntt_static_init(bf_context_t *s1)+{+    BFNTTState *s;+    int inverse, i, j, k, l;+    limb_t c, c_inv, c_inv2, m, m_inv;++    if (s1->ntt_state)+        return 0;+#if defined(__AVX2__)+    s = bf_aligned_malloc(s1, sizeof(*s), 64);+#else+    s = bf_malloc(s1, sizeof(*s));+#endif+    if (!s)+        return -1;+    memset(s, 0, sizeof(*s));+    s1->ntt_state = s;+    s->ctx = s1;+    +    for(j = 0; j < NB_MODS; j++) {+        m = ntt_mods[j];+        m_inv = init_mul_mod_fast(m);+        s->ntt_mods_div[j] = m_inv;+#if defined(__AVX2__)+        s->ntt_mods_vec[j] = _mm256_set1_pd(m);+        s->ntt_mods_inv_vec[j] = _mm256_set1_pd(1.0 / (double)m);+#endif+        c_inv2 = (m + 1) / 2; /* 1/2 */+        c_inv = 1;+        for(i = 0; i <= NTT_PROOT_2EXP; i++) {+            s->ntt_len_inv[j][i][0] = c_inv;+            s->ntt_len_inv[j][i][1] = init_mul_mod_fast2(c_inv, m);+            c_inv = mul_mod_fast(c_inv, c_inv2, m, m_inv);+        }++        for(inverse = 0; inverse < 2; inverse++) {+            c = ntt_proot[inverse][j];+            for(i = 0; i < NTT_PROOT_2EXP; i++) {+                s->ntt_proot_pow[j][inverse][NTT_PROOT_2EXP - i] = c;+                s->ntt_proot_pow_inv[j][inverse][NTT_PROOT_2EXP - i] =+                    init_mul_mod_fast2(c, m);+                c = mul_mod_fast(c, c, m, m_inv);+            }+        }+    }++    l = 0;+    for(j = 0; j < NB_MODS - 1; j++) {+        for(k = j + 1; k < NB_MODS; k++) {+#if defined(__AVX2__)+            s->ntt_mods_cr_vec[l] = _mm256_set1_pd(int_to_ntt_limb2(ntt_mods_cr[l],+                                                                    ntt_mods[k]));+#else+            s->ntt_mods_cr_inv[l] = init_mul_mod_fast2(ntt_mods_cr[l],+                                                       ntt_mods[k]);+#endif+            l++;+        }+    }+    return 0;+}++int bf_get_fft_size(int *pdpl, int *pnb_mods, limb_t len)+{+    int dpl, fft_len_log2, n_bits, nb_mods, dpl_found, fft_len_log2_found;+    int int_bits, nb_mods_found;+    limb_t cost, min_cost;+    +    min_cost = -1;+    dpl_found = 0;+    nb_mods_found = 4;+    fft_len_log2_found = 0;+    for(nb_mods = 3; nb_mods <= NB_MODS; nb_mods++) {+        int_bits = ntt_int_bits[NB_MODS - nb_mods];+        dpl = bf_min((int_bits - 4) / 2,+                     2 * LIMB_BITS + 2 * NTT_MOD_LOG2_MIN - NTT_MOD_LOG2_MAX);+        for(;;) {+            fft_len_log2 = ceil_log2((len * LIMB_BITS + dpl - 1) / dpl);+            if (fft_len_log2 > NTT_PROOT_2EXP)+                goto next;+            n_bits = fft_len_log2 + 2 * dpl;+            if (n_bits <= int_bits) {+                cost = ((limb_t)(fft_len_log2 + 1) << fft_len_log2) * nb_mods;+                //                printf("n=%d dpl=%d: cost=%" PRId64 "\n", nb_mods, dpl, (int64_t)cost);+                if (cost < min_cost) {+                    min_cost = cost;+                    dpl_found = dpl;+                    nb_mods_found = nb_mods;+                    fft_len_log2_found = fft_len_log2;+                }+                break;+            }+            dpl--;+            if (dpl == 0)+                break;+        }+    next: ;+    }+    if (!dpl_found)+        abort();+    /* limit dpl if possible to reduce fixed cost of limb/NTT conversion */+    if (dpl_found > (LIMB_BITS + NTT_MOD_LOG2_MIN) &&+        ((limb_t)(LIMB_BITS + NTT_MOD_LOG2_MIN) << fft_len_log2_found) >=+        len * LIMB_BITS) {+        dpl_found = LIMB_BITS + NTT_MOD_LOG2_MIN;+    }+    *pnb_mods = nb_mods_found;+    *pdpl = dpl_found;+    return fft_len_log2_found;+}++/* return 0 if OK, -1 if memory error */+static no_inline int fft_mul(bf_context_t *s1,+                             bf_t *res, limb_t *a_tab, limb_t a_len,+                             limb_t *b_tab, limb_t b_len, int mul_flags)+{+    BFNTTState *s;+    int dpl, fft_len_log2, j, nb_mods, reduced_mem;+    slimb_t len, fft_len;+    NTTLimb *buf1, *buf2, *ptr;+#if defined(USE_MUL_CHECK)+    limb_t ha, hb, hr, h_ref;+#endif+    +    if (ntt_static_init(s1))+        return -1;+    s = s1->ntt_state;+    +    /* find the optimal number of digits per limb (dpl) */+    len = a_len + b_len;+    fft_len_log2 = bf_get_fft_size(&dpl, &nb_mods, len);+    fft_len = (uint64_t)1 << fft_len_log2;+    //    printf("len=%" PRId64 " fft_len_log2=%d dpl=%d\n", len, fft_len_log2, dpl);+#if defined(USE_MUL_CHECK)+    ha = mp_mod1(a_tab, a_len, BF_CHKSUM_MOD, 0);+    hb = mp_mod1(b_tab, b_len, BF_CHKSUM_MOD, 0);+#endif+    if ((mul_flags & (FFT_MUL_R_OVERLAP_A | FFT_MUL_R_OVERLAP_B)) == 0) {+        if (!(mul_flags & FFT_MUL_R_NORESIZE))+            bf_resize(res, 0);+    } else if (mul_flags & FFT_MUL_R_OVERLAP_B) {+        limb_t *tmp_tab, tmp_len;+        /* it is better to free 'b' first */+        tmp_tab = a_tab;+        a_tab = b_tab;+        b_tab = tmp_tab;+        tmp_len = a_len;+        a_len = b_len;+        b_len = tmp_len;+    }+    buf1 = ntt_malloc(s, sizeof(NTTLimb) * fft_len * nb_mods);+    if (!buf1)+        return -1;+    limb_to_ntt(s, buf1, fft_len, a_tab, a_len, dpl,+                NB_MODS - nb_mods, nb_mods);+    if ((mul_flags & (FFT_MUL_R_OVERLAP_A | FFT_MUL_R_OVERLAP_B)) == +        FFT_MUL_R_OVERLAP_A) {+        if (!(mul_flags & FFT_MUL_R_NORESIZE))+            bf_resize(res, 0);+    }+    reduced_mem = (fft_len_log2 >= 14);+    if (!reduced_mem) {+        buf2 = ntt_malloc(s, sizeof(NTTLimb) * fft_len * nb_mods);+        if (!buf2)+            goto fail;+        limb_to_ntt(s, buf2, fft_len, b_tab, b_len, dpl,+                    NB_MODS - nb_mods, nb_mods);+        if (!(mul_flags & FFT_MUL_R_NORESIZE))+            bf_resize(res, 0); /* in case res == b */+    } else {+        buf2 = ntt_malloc(s, sizeof(NTTLimb) * fft_len);+        if (!buf2)+            goto fail;+    }+    for(j = 0; j < nb_mods; j++) {+        if (reduced_mem) {+            limb_to_ntt(s, buf2, fft_len, b_tab, b_len, dpl,+                        NB_MODS - nb_mods + j, 1);+            ptr = buf2;+        } else {+            ptr = buf2 + fft_len * j;+        }+        if (ntt_conv(s, buf1 + fft_len * j, ptr,+                     fft_len_log2, fft_len_log2, j + NB_MODS - nb_mods))+            goto fail;+    }+    if (!(mul_flags & FFT_MUL_R_NORESIZE))+        bf_resize(res, 0); /* in case res == b and reduced mem */+    ntt_free(s, buf2);+    buf2 = NULL;+    if (!(mul_flags & FFT_MUL_R_NORESIZE)) {+        if (bf_resize(res, len))+            goto fail;+    }+    ntt_to_limb(s, res->tab, len, buf1, fft_len_log2, dpl, nb_mods);+    ntt_free(s, buf1);+#if defined(USE_MUL_CHECK)+    hr = mp_mod1(res->tab, len, BF_CHKSUM_MOD, 0);+    h_ref = mul_mod(ha, hb, BF_CHKSUM_MOD);+    if (hr != h_ref) {+        printf("ntt_mul_error: len=%" PRId_LIMB " fft_len_log2=%d dpl=%d nb_mods=%d\n",+               len, fft_len_log2, dpl, nb_mods);+        //        printf("ha=0x" FMT_LIMB" hb=0x" FMT_LIMB " hr=0x" FMT_LIMB " expected=0x" FMT_LIMB "\n", ha, hb, hr, h_ref);+        exit(1);+    }+#endif    +    return 0;+ fail:+    ntt_free(s, buf1);+    ntt_free(s, buf2);+    return -1;+}++#else /* USE_FFT_MUL */++int bf_get_fft_size(int *pdpl, int *pnb_mods, limb_t len)+{+    return 0;+}++#endif /* !USE_FFT_MUL */
+ src/LibBF.hs view
@@ -0,0 +1,273 @@+{-# Language BlockArguments #-}+{-# Language Trustworthy #-}+-- | Computation with high-precision floats.+module LibBF+  (+    -- * Constants+    BigFloat+  , bfPosZero, bfNegZero+  , bfPosInf, bfNegInf+  , bfNaN++    -- * Conversions+  , bfFromWord+  , bfFromInt+  , bfFromDouble+  , bfFromInteger+  , bfFromString+  , bfToDouble+  , bfToString+  , bfToRep+  , BFRep(..)+  , BFNum(..)++    -- * Predicates+  , bfIsFinite+  , bfIsZero+  , bfIsNaN+  , bfCompare+  , bfSign+  , bfExponent+  , Sign(..)++    -- * Arithmetic+  , bfNeg+  , bfAdd, bfSub, bfMul, bfDiv+  , bfMulWord, bfMulInt, bfMul2Exp+  , bfSqrt+  , bfPow++    -- * Rounding+  , bfRoundFloat, bfRoundInt++    -- * Mutability+  , bfUnsafeThaw+  , bfUnsafeFreeze++    -- * Limits+++    -- * Configuration+  , module LibBF.Opts+  ) where+++import Data.Word+import Data.Int+import System.IO.Unsafe++import LibBF.Mutable as M+import LibBF.Opts+import Control.DeepSeq+++-- | Arbitrary precision floating point numbers.+newtype BigFloat = BigFloat BF++instance NFData BigFloat where+  rnf x = x `seq` ()+++instance Show BigFloat where+  show = bfToString 16 (showFreeMin Nothing <> addPrefix)++--------------------------------------------------------------------------------+{-# NOINLINE ctxt #-}+{-# OPTIONS_GHC -fno-cse #-}+ctxt :: BFContext+ctxt = unsafePerformIO newContext++newBigFloat :: (BF -> IO ()) -> BigFloat+newBigFloat f = unsafe $+  do bf <- new ctxt+     f bf+     pure (BigFloat bf)++newBigFloat' :: (BF -> IO a) -> (BigFloat,a)+newBigFloat' f = unsafe $+  do bf <- new ctxt+     a <- f bf+     pure (BigFloat bf, a)++unsafe :: IO a -> a+unsafe = unsafePerformIO++--------------------------------------------------------------------------------+-- Constants++-- | Positive zero.+bfPosZero :: BigFloat+bfPosZero = newBigFloat (setZero Pos)++-- | Negative zero.+bfNegZero :: BigFloat+bfNegZero = newBigFloat (setZero Neg)++-- | Positive infinity.+bfPosInf :: BigFloat+bfPosInf = newBigFloat (setInf Pos)++-- | Negative infinity.+bfNegInf :: BigFloat+bfNegInf = newBigFloat (setInf Neg)++-- | Not-a-number.+bfNaN :: BigFloat+bfNaN = newBigFloat setNaN++-- | A floating point number corresponding to the given word.+bfFromWord :: Word64 -> BigFloat+bfFromWord = newBigFloat . setWord++-- | A floating point number corresponding to the given int.+bfFromInt :: Int64 -> BigFloat+bfFromInt = newBigFloat . setInt++-- | A floating point number corresponding to the given double.+bfFromDouble :: Double -> BigFloat+bfFromDouble = newBigFloat . setDouble++-- | A floating point number corresponding to the given integer.+bfFromInteger :: Integer -> BigFloat+bfFromInteger = newBigFloat . setInteger++-- | IEEE 754 equality+instance Eq BigFloat where+  BigFloat x == BigFloat y = unsafe (cmpEq x y)++-- | IEEE 754 comparisons+instance Ord BigFloat where+  BigFloat x < BigFloat y  = unsafe (cmpLT x y)+  BigFloat x <= BigFloat y = unsafe (cmpLEQ x y)+++{-| Compare the two numbers.  The special values are ordered like this:++      * -0 < 0+      * NaN == NaN+      * NaN is larger than all other numbers++Note that this differs from `(<=)`+-}+bfCompare :: BigFloat -> BigFloat -> Ordering+bfCompare (BigFloat x) (BigFloat y) = unsafe (cmp x y)+++-- | Is this a "normal" (i.e., non-infinite, non NaN) number.+bfIsFinite :: BigFloat -> Bool+bfIsFinite (BigFloat x) = unsafe (isFinite x)++-- | Is this value NaN.+bfIsNaN :: BigFloat -> Bool+bfIsNaN (BigFloat x) = unsafe (M.isNaN x)++-- | Get the sign of a number.  Assumes the input is not NaN.+bfSign :: BigFloat -> Maybe Sign+bfSign (BigFloat x) = unsafe (getSign x)++-- | Get the exponent for the given number.+-- Infinity, zero and NaN do not have an exponent.+bfExponent :: BigFloat -> Maybe Int64+bfExponent (BigFloat x) = unsafe (getExp x)++-- | Is this value a zero.+bfIsZero :: BigFloat -> Bool+bfIsZero (BigFloat x) = unsafe (isZero x)++-- | Negate a floating point number.+bfNeg :: BigFloat -> BigFloat+bfNeg (BigFloat x) = newBigFloat (\bf -> setBF x bf >> fneg bf)++-- | Add two numbers useing the given options.+bfAdd :: BFOpts -> BigFloat -> BigFloat -> (BigFloat,Status)+bfAdd opt (BigFloat x) (BigFloat y) = newBigFloat' (fadd opt x y)++-- | Subtract two numbers useing the given options.+bfSub :: BFOpts -> BigFloat -> BigFloat -> (BigFloat,Status)+bfSub opt (BigFloat x) (BigFloat y) = newBigFloat' (fsub opt x y)++-- | Multiply two numbers using the given options.+bfMul :: BFOpts -> BigFloat -> BigFloat -> (BigFloat,Status)+bfMul opt (BigFloat x) (BigFloat y) = newBigFloat' (fmul opt x y)++-- | Multiply a number and a word, using the given options.+bfMulWord :: BFOpts -> BigFloat -> Word64 -> (BigFloat,Status)+bfMulWord opt (BigFloat x) y = newBigFloat' (fmulWord opt x y)++-- | Multiply a number and an int, using the given options.+bfMulInt :: BFOpts -> BigFloat -> Int64 -> (BigFloat,Status)+bfMulInt opt (BigFloat x) y = newBigFloat' (fmulInt opt x y)++-- | Multiply a number by @2^e@.+bfMul2Exp :: BFOpts -> BigFloat -> Int64 -> (BigFloat,Status)+bfMul2Exp opt (BigFloat x) e = newBigFloat' (\p ->+  do setBF x p+     fmul2Exp opt e p)++-- | Divide two numbers useing the given options.+bfDiv :: BFOpts -> BigFloat -> BigFloat -> (BigFloat,Status)+bfDiv opt (BigFloat x) (BigFloat y) = newBigFloat' (fdiv opt x y)++-- | Square root of two numbers useing the given options.+bfSqrt :: BFOpts -> BigFloat -> (BigFloat,Status)+bfSqrt opt (BigFloat x) = newBigFloat' (fsqrt opt x)++-- | Round to a float matching the input parameters.+bfRoundFloat :: BFOpts -> BigFloat -> (BigFloat,Status)+bfRoundFloat opt (BigFloat x) = newBigFloat' (\bf ->+  do setBF x bf+     fround opt bf+  )++-- | Round to an integer using the given parameters.+bfRoundInt :: BFOpts -> BigFloat -> (BigFloat,Status)+bfRoundInt opt (BigFloat x) = newBigFloat' (\bf ->+  do setBF x bf+     frint opt bf+  )++-- | Exponentiate a word to a positive integer power.+bfPow :: BFOpts -> BigFloat -> BigFloat -> (BigFloat, Status)+bfPow opts (BigFloat x) (BigFloat y) = newBigFloat' (fpow opts x y)++-- | Constant to a 'Double'+bfToDouble :: RoundMode -> BigFloat -> (Double, Status)+bfToDouble r (BigFloat x) = unsafe (toDouble r x)++-- | Render as a 'String', using the given settings.+bfToString :: Int {- ^ Base -} -> ShowFmt -> BigFloat -> String+bfToString radix opts (BigFloat x) =+  unsafe (toString radix opts x)++-- | Parse a number from the given string.+-- Returns @NaN` if the string does not correspond to a number we recognize.+bfFromString :: Int {- ^ Base -} -> BFOpts -> String -> (BigFloat,Status)+bfFromString radix opts str =+  newBigFloat' \bf ->+  do (status,_,usedAll) <- setString radix opts str bf+     if usedAll+        then pure status+        else do setNaN bf+                pure Ok++-- | The float as an exponentiated 'Integer'.+bfToRep :: BigFloat -> BFRep+bfToRep (BigFloat x) = unsafe (toRep x)++-- | Make a number mutable.+-- WARNING: This does not copy the number,+-- so it could break referential transperancy.+bfUnsafeThaw :: BigFloat -> BF+bfUnsafeThaw (BigFloat x) = x++-- | Make a number immutable.+-- WARNING: This does not copy the number,+-- so it could break referential transperancy.+bfUnsafeFreeze :: BF -> BigFloat+bfUnsafeFreeze = BigFloat++--------------------------------------------------------------------------------++++
+ src/LibBF/Mutable.hsc view
@@ -0,0 +1,590 @@+{-# Language ForeignFunctionInterface, CApiFFI #-}+{-# Language PatternSynonyms #-}+{-# Language MultiWayIf #-}+{-# Language BlockArguments #-}+-- | Mutable big-float computation.+module LibBF.Mutable+  ( -- * Allocation+    newContext, BFContext+  , new, BF++    -- * Assignment+  , setNaN+  , setZero+  , setInf+  , Sign(..)+  , setWord+  , setInt+  , setDouble+  , setInteger+  , setBF+  , setString++    -- * Queries and Comparisons+  , cmpEq+  , cmpLT+  , cmpLEQ+  , cmpAbs+  , cmp+  , getSign+  , getExp++  , isFinite+  , LibBF.Mutable.isNaN+  , isZero++    -- * Arithmetic+  , fneg+  , fadd+  , faddInt+  , fsub+  , fmul+  , fmulInt+  , fmulWord+  , fmul2Exp+  , fdiv+  , fsqrt+  , fpow+  , fround+  , frint++  -- * Convert from a number+  , toDouble+  , toString+  , toRep, BFRep(..), BFNum(..)++  -- * Configuration+  , module LibBF.Opts+  , toChunks++  ) where+++import Foreign.Marshal.Alloc(alloca,free)+import Foreign.Ptr(Ptr,FunPtr,minusPtr)+import Foreign.ForeignPtr+import Foreign.C.Types+import Foreign.C.String+import Data.Word+import Data.Int+import Data.Bits+import Data.List(unfoldr)+import Control.Monad(foldM,when)+import Control.Exception(bracket)+import GHC.IO.Encoding(getForeignEncoding,setForeignEncoding,char8)++import Foreign.Storable++#include <libbf.h>++import LibBF.Opts++-- | State of the current computation context.+newtype BFContext = BFContext (ForeignPtr BFContext)++foreign import ccall "bf_context_init_hs"+  bf_context_init_hs :: Ptr BFContext -> IO ()++foreign import ccall "&bf_context_end"+  bf_context_end :: FunPtr (Ptr BFContext -> IO ())++{-| Allocate a new numeric context. -}+newContext :: IO BFContext+newContext =+  do fptr <- mallocForeignPtrBytes #{size bf_context_t}+     withForeignPtr fptr bf_context_init_hs+     addForeignPtrFinalizer bf_context_end fptr+     pure (BFContext fptr)+++-- | A mutable high precision floating point number.+newtype BF = BF (ForeignPtr BF)++foreign import ccall "bf_init"+  bf_init :: Ptr BFContext -> Ptr BF -> IO ()++foreign import ccall "&bf_delete_hs"+  bf_delete :: FunPtr (Ptr BF -> IO ())++{-| Allocate a new number.  Starts off as zero. -}+new :: BFContext -> IO BF+new (BFContext fctx) =+  withForeignPtr fctx \ctx ->+  do fptr <- mallocForeignPtrBytes #{size bf_t}+     withForeignPtr fptr (bf_init ctx)+     addForeignPtrFinalizer bf_delete fptr+     pure (BF fptr)++--------------------------------------------------------------------------------+-- FFI Helpers++signToC :: Sign -> CInt+signToC s = case s of+              Pos -> 0+              Neg -> 1++asSign :: CInt -> Sign+asSign s = if s == 0 then Pos else Neg++asBool :: CInt -> Bool+asBool = (/= 0)++asOrd :: CInt -> Ordering+asOrd x+  | x < 0     = LT+  | x > 0     = GT+  | otherwise = EQ+++bf1 :: (Ptr BF -> IO a) -> BF -> IO a+bf1 f (BF fout) = withForeignPtr fout f++bfQuery :: (Ptr BF -> IO CInt) -> BF -> IO Bool+bfQuery f = bf1 (fmap asBool . f)++bfRel :: (Ptr BF -> Ptr BF -> IO CInt) -> BF -> BF -> IO Bool+bfRel f = bf2 \x y -> asBool <$> f y x++bfOrd :: (Ptr BF -> Ptr BF -> IO CInt) -> BF -> BF -> IO Ordering+bfOrd f = bf2 \x y -> asOrd <$> f y x++bf2 :: (Ptr BF -> Ptr BF -> IO a) -> BF -> BF -> IO a+bf2 f (BF fin1) (BF fout) =+  withForeignPtr fin1 \in1 ->+  withForeignPtr fout \out1 ->+    f out1 in1++bf3 :: (Ptr BF -> Ptr BF -> Ptr BF -> IO a) -> BF -> BF -> BF -> IO a+bf3 f (BF fin1) (BF fin2) (BF fout) =+  withForeignPtr fin1 \in1 ->+  withForeignPtr fin2 \in2 ->+  withForeignPtr fout \out ->+    f out in1 in2+++++++--------------------------------------------------------------------------------+-- Assignment+++-- | Indicates if a number is positive or negative.+data Sign = Neg {-^ Negative -} | Pos {-^ Positive -} +             deriving (Eq,Ord,Show)+++foreign import ccall "bf_set_nan"+  bf_set_nan :: Ptr BF -> IO ()++-- | Assign @NaN@ to the number.+setNaN :: BF -> IO ()+setNaN (BF fptr) = withForeignPtr fptr bf_set_nan+++foreign import ccall "bf_set_zero"+  bf_set_zero :: Ptr BF -> CInt -> IO ()++-- | Assign a zero to the number.+setZero :: Sign -> BF -> IO ()+setZero sig = bf1 (`bf_set_zero` signToC sig)+++foreign import ccall "bf_set_inf"+  bf_set_inf :: Ptr BF -> CInt -> IO ()++-- | Assign an infinty to the number.+setInf :: Sign -> BF -> IO ()+setInf sig = bf1 (`bf_set_inf` signToC sig)+++foreign import ccall "bf_set_ui"+  bf_set_ui :: Ptr BF -> Word64 -> IO ()++{-| Assign from a word -}+setWord :: Word64 -> BF -> IO ()+setWord w = bf1 (`bf_set_ui` w)+++foreign import ccall "bf_set_si"+  bf_set_si :: Ptr BF -> Int64 -> IO ()++{-| Assign from an int -}+setInt :: Int64 -> BF -> IO ()+setInt s = bf1 (`bf_set_si` s)++-- | Set an integer.  If the integer is larger than the primitive types,+-- this does repreated Int64 additions and multiplications.+setInteger :: Integer -> BF -> IO ()+setInteger n0 bf0+  | n0 >= 0 && n0 <= toInteger (maxBound :: Word64) =+    setWord (fromInteger n0) bf0+  | n0 < 0 && n0 >= toInteger (minBound :: Int64) =+    setInt (fromInteger n0) bf0+  | otherwise =+  do setZero Pos bf0+     go (abs n0) bf0+     when (n0 < 0) (fneg bf0)+  where+  chunk = toInteger (maxBound :: Int64) + 1++  go n bf+    | n == 0 = pure ()+    | otherwise =+      do let (next,this) = n `divMod` chunk+         go next bf+         Ok <- fmulWord infPrec bf (fromIntegral chunk) bf+         Ok <- faddInt  infPrec bf (fromIntegral this)  bf+         pure ()++-- | Chunk a non-negative integer into words,+-- least significatn first+toChunks :: Integer -> [LimbT]+toChunks = unfoldr step+  where+  step n = if n == 0 then Nothing+                     else Just (leastChunk n, n `shiftR` unit)++  unit = #{const LIMB_BITS} :: Int+  mask = (1 `shiftL` unit) - 1++  leastChunk :: Integer -> LimbT+  leastChunk n = fromIntegral (n .&. mask)++++foreign import ccall "bf_set_float64"+  bf_set_float64 :: Ptr BF -> Double -> IO ()++{-| Assign from a double -}+setDouble :: Double -> BF -> IO ()+setDouble d = bf1 (`bf_set_float64` d)+++foreign import ccall "bf_set"+  bf_set :: Ptr BF -> Ptr BF -> IO ()++{-| Assign from another number. -}+setBF :: BF -> BF {-^ This number is changed -} -> IO ()+setBF = bf2 (\out in1 -> bf_set out in1)+++--------------------------------------------------------------------------------+-- Comparisons++foreign import capi "libbf.h bf_cmp_eq"+  bf_cmp_eq :: Ptr BF -> Ptr BF -> IO CInt++{-| Check if the two numbers are equal. -}+cmpEq :: BF -> BF -> IO Bool+cmpEq = bfRel bf_cmp_eq+++foreign import capi "libbf.h bf_cmp_lt"+  bf_cmp_lt :: Ptr BF -> Ptr BF -> IO CInt++{-| Check if the first number is strictly less than the second. -}+cmpLT :: BF -> BF -> IO Bool+cmpLT = bfRel bf_cmp_lt+++foreign import capi "libbf.h bf_cmp_le"+  bf_cmp_le :: Ptr BF -> Ptr BF -> IO CInt++{-| Check if the first number is less than, or equal to, the second. -}+cmpLEQ :: BF -> BF -> IO Bool+cmpLEQ = bfRel bf_cmp_le+++foreign import ccall "bf_cmpu"+  bf_cmpu :: Ptr BF -> Ptr BF -> IO CInt++{-| Compare the absolute values of the two numbers. See also 'cmp'. -}+cmpAbs :: BF -> BF -> IO Ordering+cmpAbs = bfOrd bf_cmpu+++foreign import ccall "bf_cmp_full"+  bf_cmp_full :: Ptr BF -> Ptr BF -> IO CInt++{-| Compare the two numbers.  The special values are ordered like this:++      * -0 < 0+      * NaN == NaN+      * NaN is larger than all other numbers+-}+cmp :: BF -> BF -> IO Ordering+cmp = bfOrd bf_cmp_full++++++++foreign import capi "libbf.h bf_is_finite"+  bf_is_finite :: Ptr BF -> IO CInt++foreign import capi "libbf.h bf_is_nan"+  bf_is_nan :: Ptr BF -> IO CInt++foreign import capi "libbf.h bf_is_zero"+  bf_is_zero :: Ptr BF -> IO CInt++{-| Check if the number is "normal", i.e. (not infinite or NaN) -}+isFinite :: BF -> IO Bool+isFinite = bfQuery bf_is_finite++{-| Check if the number is NaN -}+isNaN :: BF -> IO Bool+isNaN = bfQuery bf_is_nan++{-| Check if the given number is a zero. -}+isZero :: BF -> IO Bool+isZero = bfQuery bf_is_zero++++++++foreign import capi "libbf.h bf_neg"+  bf_neg :: Ptr BF -> IO ()++foreign import ccall "bf_add"+  bf_add :: Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_add_si"+  bf_add_si :: Ptr BF -> Ptr BF -> Int64 -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_sub"+  bf_sub :: Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_mul"+  bf_mul :: Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_mul_si"+  bf_mul_si :: Ptr BF -> Ptr BF -> Int64 -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_mul_ui"+  bf_mul_ui :: Ptr BF -> Ptr BF -> Word64 -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_mul_2exp"+  bf_mul_2exp :: Ptr BF -> SLimbT -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_div"+  bf_div :: Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status+++foreign import ccall "bf_pow"+  bf_pow :: Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_round"+  bf_round :: Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_rint"+  bf_rint :: Ptr BF -> LimbT -> FlagsT -> IO Status++foreign import ccall "bf_sqrt"+  bf_sqrt :: Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status++++bfArith :: (Ptr BF -> Ptr BF -> Ptr BF -> LimbT -> FlagsT -> IO Status) ->+           BFOpts -> BF -> BF -> BF -> IO Status+bfArith fun (BFOpts prec flags) (BF fa) (BF fb) (BF fr) =+  withForeignPtr fa \a ->+  withForeignPtr fb \b ->+  withForeignPtr fr \r ->+  fun r a b prec flags+++++-- | Negate the number.+fneg :: BF -> IO ()+fneg = bf1 bf_neg++-- | Add two numbers, using the given settings, and store the+-- result in the last.+fadd :: BFOpts -> BF -> BF -> BF -> IO Status+fadd = bfArith bf_add++-- | Add a number and an int64 and store the result in the last.+faddInt :: BFOpts -> BF -> Int64 -> BF -> IO Status+faddInt (BFOpts p f) x y z = bf2 (\out in1 -> bf_add_si out in1 y p f) x z++-- | Subtract two numbers, using the given settings, and store the+-- result in the last.+fsub :: BFOpts -> BF -> BF -> BF -> IO Status+fsub = bfArith bf_sub++-- | Multiply two numbers, using the given settings, and store the+-- result in the last.+fmul :: BFOpts -> BF -> BF -> BF -> IO Status+fmul = bfArith bf_mul++-- | Multiply the number by the given word, and store the result+-- in the second number.+fmulWord :: BFOpts -> BF -> Word64 -> BF -> IO Status+fmulWord (BFOpts p f) x y z = bf2 (\out in1 -> bf_mul_ui out in1 y p f) x z++-- | Multiply the number by the given int, and store the result+-- in the second number.+fmulInt :: BFOpts -> BF -> Int64 -> BF -> IO Status+fmulInt (BFOpts p f) x y z = bf2 (\out in1 -> bf_mul_si out in1 y p f) x z++-- | Multiply the number by @2^e@.+fmul2Exp :: BFOpts -> Int64 -> BF -> IO Status+fmul2Exp (BFOpts p f) e = bf1 (\out -> bf_mul_2exp out e p f)++-- | Divide two numbers, using the given settings, and store the+-- result in the last.+fdiv :: BFOpts -> BF -> BF -> BF -> IO Status+fdiv = bfArith bf_div++-- | Compute the square root of the first number and store the result+-- in the second.+fsqrt :: BFOpts -> BF -> BF -> IO Status+fsqrt (BFOpts p f) = bf2 (\res inp -> bf_sqrt res inp p f)++-- | Round to the nearest float matching the configuration parameters.+fround :: BFOpts -> BF -> IO Status+fround (BFOpts p f) = bf1 (\ptr -> bf_round ptr p f)++-- | Round to the neareset integer.+frint :: BFOpts -> BF -> IO Status+frint (BFOpts p f) = bf1 (\ptr -> bf_rint ptr p f)++-- | Exponentiate the first number by the second,+-- and store the result in the third number.+fpow :: BFOpts -> BF -> BF -> BF -> IO Status+fpow (BFOpts prec flags) = bf3 (\out in1 in2 -> bf_pow out in1 in2 prec flags)++++++--------------------------------------------------------------------------------+-- export++foreign import ccall "bf_get_float64"+  bf_get_float64 :: Ptr BF -> Ptr Double -> RoundMode -> IO Status++-- | Get the current value of a 'BF' as a Haskell `Double`.+toDouble :: RoundMode -> BF -> IO (Double, Status)+toDouble r = bf1 (\inp ->+  alloca (\out ->+   do s <- bf_get_float64 inp out r+      d <- peek out+      pure (d, s)+  ))+++foreign import ccall "bf_atof"+  bf_atof ::+    Ptr BF -> CString -> Ptr CString -> CInt -> LimbT -> FlagsT -> IO CInt+++{- | Set the value to the float parsed out of the given string.+  * The radix should not exceed 'LibBF.Opts.maxRadix'.+  * Sets the number to @NaN@ on failure.+  * Assumes that characters are encoded with a single byte each.+  * Retruns:+      - Status for the conversion+      - How many bytes we consumed+      - Did we consume the whole input+-}+setString :: Int -> BFOpts -> String -> BF -> IO (Status,Int,Bool)+setString radix (BFOpts prec flags) inStr =+  bf1    \bfPtr ->+  alloca \nextPtr ->+  bracket (getForeignEncoding >>= \e -> setForeignEncoding char8 >> pure e)+          setForeignEncoding+  \_enc ->+  withCStringLen inStr \(strPtr,len) ->+  do stat <- bf_atof bfPtr strPtr nextPtr (fromIntegral radix) prec flags+     next <- peek nextPtr+     let consumed = next `minusPtr` strPtr+         usedAll = len == consumed+     consumed `seq` usedAll `seq` pure (Status stat, consumed, usedAll)+++foreign import ccall "bf_ftoa"+  bf_ftoa :: Ptr CSize -> Ptr BF -> CInt -> LimbT -> FlagsT -> IO CString++-- | Render a big-float as a Haskell string.+-- The radix should not exceed 'LibBF.Opts.maxRadix'.+toString :: Int -> ShowFmt -> BF -> IO String+toString radix (ShowFmt ds flags) =+  bf1 \inp ->+  alloca \out ->+  do ptr <- bf_ftoa out inp (fromIntegral radix) ds flags+     len <- peek out+     if len > 0+       then+         do res <- peekCString ptr+            free ptr+            pure res+       else pure "(error)" -- XXX: throw an exception+++-- | An explicit representation for big nums.+data BFRep  = BFRep !Sign !BFNum    -- ^ A signed number+            | BFNaN                 -- ^ Not a number+              deriving (Eq,Ord,Show)++-- | Representations for unsign floating point numbers.+data BFNum  = Zero                 -- ^ zero+            | Num Integer !Int64   -- ^ @x * 2 ^ y@+            | Inf                  -- ^ infinity+              deriving (Eq,Ord,Show)++-- | Returns 'Nothing' for @NaN@.+getSign :: BF -> IO (Maybe Sign)+getSign = bf1 (\ptr ->+  do e <- #{peek bf_t, expn} ptr+     if (e :: SLimbT) == #{const BF_EXP_NAN}+        then pure Nothing+        else (Just . asSign) <$> #{peek bf_t, sign} ptr)++-- | Get the exponent of the number.+-- Returns 'Nothing' for inifinity, zero and NaN.+getExp :: BF -> IO (Maybe Int64)+getExp = bf1 (\ptr ->+  do e <- #{peek bf_t, expn} ptr+     pure $! if (e :: SLimbT) < #{const BF_EXP_INF} &&+                e > #{const BF_EXP_ZERO} then Just (fromIntegral e)+                                         else Nothing)+++-- | Get the represnetation of the number.+toRep :: BF -> IO BFRep+toRep = bf1 (\ptr ->+  do s <- #{peek bf_t, sign} ptr+     let sgn = if asBool s then Neg else Pos+     e <- #{peek bf_t, expn} ptr+     if | e == #{const BF_EXP_NAN}  -> pure BFNaN+        | e == #{const BF_EXP_INF}  -> pure (BFRep sgn Inf)+        | e == #{const BF_EXP_ZERO} -> pure (BFRep sgn Zero)+        | otherwise ->+        do l <- #{peek bf_t, len}  ptr+           p <- #{peek bf_t, tab}  ptr+           let len = fromIntegral (l :: Word64) :: Int+               -- This should not really limit precision as it counts+               -- number of Word64s (not bytes)++               step x i = do w <- peekElemOff p i+                             pure ((x `shiftL` 64) + fromIntegral (w :: Word64))++           base <- foldM step 0 (reverse (take len [ 0 .. ]))+           let bias = 64 * fromIntegral len+               norm bs bi+                 | even bs    = norm (bs `shiftR` 1) (bi - 1)+                 | otherwise  = BFRep sgn (Num bs (e - bi))++           pure (norm base bias) -- (BFRep sgn (Num base (e - bias)))+  )+
+ src/LibBF/Opts.hsc view
@@ -0,0 +1,330 @@+{-# Language PatternSynonyms, CApiFFI, ViewPatterns #-}+-- | Configuration and results for FP computation.+module LibBF.Opts+  (  -- * Options+    BFOpts(..)+  , allowSubnormal++    -- ** Presets+  , float16+  , float32+  , float64+  , float128+  , float256++    -- ** Precision+  , precBits+  , precBitsMin+  , precBitsMax+  , infPrec++    -- ** Exponent Size+  , expBits+  , expBitsMin+  , expBitsMax++    -- ** Rounding mode+  , rnd+  , RoundMode(..)+  , pattern NearEven+  , pattern ToZero+  , pattern ToNegInf+  , pattern ToPosInf+  , pattern NearAway+  , pattern Away+  , pattern Faithful+++  -- ** Pretty printing options+  , ShowFmt(..)+  , showRnd+  , showFixed+  , showFrac+  , showFree+  , showFreeMin+  , addPrefix+  , forceExp+  , radixMax++  -- * Status+  , Status(..)+  , pattern Ok+  , pattern InvalidOp+  , pattern DivideByZero+  , pattern Overflow+  , pattern Underflow+  , pattern Inexact+  , pattern MemError++  -- * Internal+  , LimbT+  , SLimbT+  , FlagsT+  )+  where++import Data.Word+import Data.Int+import Foreign.C.Types+import Data.Bits+import Data.List+#include <libbf.h>++-- | Internal: type for limbs+type LimbT  = #{type limb_t}++-- | Internal: type for signed limbs+type SLimbT = #{type slimb_t}++-- | Internal: type for flags+type FlagsT = #{type bf_flags_t}++-- | Specifies various computation settings, combined with 'Semigroup'.+data BFOpts = BFOpts !LimbT !FlagsT++instance Semigroup BFOpts where+  BFOpts l f <> BFOpts l1 f1 = BFOpts (max l l1) (f .|. f1)+++-- | Use infinite precision.  This should be used with caution,+-- as it could exhause memory, and at the moment the library+-- does not handle this gracefully at all (core dumps).+infPrec :: BFOpts+infPrec = BFOpts #{const BF_PREC_INF} 0++-- | Use this many bits to represent the mantissa in the computation.+-- The input should be in the interval defined by 'precMin' and 'precMax'+precBits :: Int -> BFOpts+precBits n = BFOpts (fromIntegral n) 0++-- | Use the given rounding mode.+-- If none is specified, then the default is 'NearEven'.+rnd :: RoundMode -> BFOpts+rnd (RoundMode r) = BFOpts 0 r++-- | The smallest supported precision (in bits).+foreign import capi "libbf.h value BF_PREC_MIN"+  precBitsMin :: Int++-- | The largest supported precision (in bits).+-- Memory could run out before we run out of precision.+foreign import capi "libbf.h value BF_PREC_MAX"+  precBitsMax :: Int++{- | Allow denormalized answers. -}+allowSubnormal :: BFOpts+allowSubnormal = BFOpts 0 #{const BF_FLAG_SUBNORMAL}+++foreign import capi "libbf.h bf_set_exp_bits"+  bf_set_exp_bits :: CInt -> FlagsT++-- | Set how many bits to use to represent the exponent.+-- Should fit in the range defined by 'expBitsMin' and 'expBitsMax'.+expBits :: Int -> BFOpts+expBits n = BFOpts 0 (bf_set_exp_bits (fromIntegral n))++{-| The smallest supported number of bits in the exponent. -}+foreign import capi "libbf.h value BF_EXP_BITS_MIN"+  expBitsMin :: Int++{-| The largest number of exponent bits supported. -}+foreign import capi "libbf.h value BF_EXP_BITS_MAX"+  expBitsMax :: Int++++--------------------------------------------------------------------------------++-- | Precision 11, exponent 5+float16:: RoundMode -> BFOpts+float16 r = rnd r <> precBits 11 <> expBits 5++-- | Precision 24, exponent 8+float32 :: RoundMode -> BFOpts+float32 r = rnd r <> precBits 24 <> expBits 8++-- | Precision 53, exponent 11+float64 :: RoundMode -> BFOpts+float64 r = rnd r <> precBits 53 <> expBits 11++-- | Precision 113, exponent 15+float128 :: RoundMode -> BFOpts+float128 r = rnd r <> precBits 113 <> expBits 15++-- | Precision 237, exponent 19+float256 :: RoundMode -> BFOpts+float256 r = rnd r <> precBits 237 <> expBits 19+++--------------------------------------------------------------------------------++-- | Settings for rendering numbers as 'String'.+data ShowFmt = ShowFmt !LimbT !FlagsT++-- | Use this rounding mode.+showRnd :: RoundMode -> ShowFmt+showRnd (RoundMode r) = ShowFmt 1 r++instance Semigroup ShowFmt where+  ShowFmt a x <> ShowFmt b y = ShowFmt (max a b) (x .|. y)++{-| Show this many significant digits total . -}+showFixed :: Word64 -> ShowFmt+showFixed n = ShowFmt n #{const BF_FTOA_FORMAT_FIXED}++{-| Show this many digits after the decimal point. -}+showFrac :: Word64 -> ShowFmt+showFrac n = ShowFmt n #{const BF_FTOA_FORMAT_FRAC}++{-| Use as many digits as necessary to match the required precision+   rounding to nearest and the subnormal+exponent configuration of 'FlagsT'.+   The result is meaningful only if the input is already rounded to+   the wanted precision.++   Infinite precision, indicated by giving 'Nothing' for the precision+   is supported when the radix is a power of two. -}+showFree :: Maybe Word64 -> ShowFmt+showFree mb = ShowFmt prec #{const BF_FTOA_FORMAT_FREE}+  where prec = case mb of+                 Nothing -> #{const BF_PREC_INF}+                 Just n  -> n+++{-| same as 'showFree' but uses the minimum number of digits+(takes more computation time). -}+showFreeMin :: Maybe Word64 -> ShowFmt+showFreeMin mb = ShowFmt prec #{const BF_FTOA_FORMAT_FREE_MIN}+  where prec = case mb of+                 Nothing -> #{const BF_PREC_INF}+                 Just n  -> n++++{- | add 0x prefix for base 16, 0o prefix for base 8 or 0b prefix for+   base 2 if non zero value -}+addPrefix :: ShowFmt+addPrefix = ShowFmt 0 #{const BF_FTOA_ADD_PREFIX}++-- | Show in exponential form.+forceExp :: ShowFmt+forceExp = ShowFmt 0 #{const BF_FTOA_FORCE_EXP}+++-- | Maximum radix when rendering to a for @bf_atof@ and @bf_froa@.+foreign import capi "libbf.h value BF_RADIX_MAX"+  radixMax :: Int++++++--------------------------------------------------------------------------------+-- | Specifies how to round when the result can't be precise.+newtype RoundMode = RoundMode FlagsT+                      deriving Show++{-| Round to nearest, ties go to even. -}+pattern NearEven :: RoundMode+pattern NearEven = RoundMode #{const BF_RNDN}++{-| Round toward zero. -}+pattern ToZero :: RoundMode+pattern ToZero = RoundMode #{const BF_RNDZ}++{-| Round down (toward -inf). -}+pattern ToNegInf :: RoundMode+pattern ToNegInf = RoundMode #{const BF_RNDD}++{-| Round up (toward +inf). -}+pattern ToPosInf :: RoundMode+pattern ToPosInf = RoundMode #{const BF_RNDU}++{-| Round to nearest, ties go away from zero. -}+pattern NearAway :: RoundMode+pattern NearAway = RoundMode #{const BF_RNDNA}++{-| Round away from zero -}+pattern Away :: RoundMode+pattern Away = RoundMode #{const BF_RNDA}++{-| Faithful rounding (nondeterministic, either 'ToPosInf' or 'ToNegInf').+    The 'Inexact' flag is always set. -}+pattern Faithful :: RoundMode+pattern Faithful = RoundMode #{const BF_RNDF}+++--------------------------------------------------------------------------------++-- | A set of flags indicating things that might go wrong.+newtype Status = Status CInt deriving (Eq,Ord)++checkStatus :: CInt -> Status -> Bool+checkStatus n (Status x) = (x .&. n) > 0++-- | Succeeds if everything is OK.+pattern Ok :: Status+pattern Ok = Status 0++-- | We tried to perform an invalid operation.+pattern InvalidOp :: Status+pattern InvalidOp <- (checkStatus #{const BF_ST_INVALID_OP} -> True)+  where InvalidOp = Status #{const BF_ST_INVALID_OP}++-- | We divided by zero.+pattern DivideByZero :: Status+pattern DivideByZero <- (checkStatus #{const BF_ST_DIVIDE_ZERO} -> True)+  where DivideByZero = Status #{const BF_ST_DIVIDE_ZERO}++-- | The result can't be represented because it is too large.+pattern Overflow :: Status+pattern Overflow <- (checkStatus #{const BF_ST_OVERFLOW} -> True)+  where Overflow = Status #{const BF_ST_OVERFLOW}++-- | The result can't be represented because it is too small.+pattern Underflow :: Status+pattern Underflow <- (checkStatus #{const BF_ST_UNDERFLOW} -> True)+  where Underflow = Status #{const BF_ST_UNDERFLOW}++-- | The result is not exact.+pattern Inexact :: Status+pattern Inexact <- (checkStatus #{const BF_ST_INEXACT} -> True)+  where Inexact = Status #{const BF_ST_INEXACT}++-- | Memory error.  @NaN@ is returned.+pattern MemError :: Status+pattern MemError <- (checkStatus #{const BF_ST_MEM_ERROR} -> True)+  where MemError = Status #{const BF_ST_MEM_ERROR}++instance Show Status where+  show x@(Status i) = case x of+                        Ok -> "Ok"+                        _  -> case checkInv of+                                [] -> "(Status " ++ show i ++ ")"+                                xs -> "[" ++ intercalate "," xs ++ "]"+    where+    checkInv = case x of+                 InvalidOp -> "InvalidOp" : checkZ+                 _         -> checkZ++    checkZ = case x of+               DivideByZero -> "DivideByZero" : checkO+               _            -> checkO++    checkO = case x of+               Overflow -> "Overflow" : checkU+               _        -> checkU++    checkU = case x of+               Underflow -> "Underflow" : checkI+               _ -> checkI++    checkI = case x of+               Inexact -> "Inexact" : checkM+               _       -> checkM++    checkM = case x of+               MemError -> ["MemError"]+               _        -> []++
+ tests/RunUnitTests.hs view
@@ -0,0 +1,44 @@+{-# Language BlockArguments #-}+module Main(main) where++import System.Exit(exitFailure)+import System.IO(hPutStrLn,stderr)+import Control.Monad(unless)++import LibBF+++main :: IO ()+main =+  do putStrLn $ bfToString 16 (showFree Nothing) bfNaN+     print $ bfFromString 10 (expBits 3 <> precBits 2 <> rnd ToZero) "0.001"+     print $ bfFromString 10 (expBits 3 <> precBits 2 <> rnd ToZero) "1.0e200"+     dblTest "+" (+) (bfAdd (float64 NearEven)) 1 2+     dblTest "/" (/) (bfDiv (float64 NearEven)) 1 0++check :: String -> Bool -> IO ()+check x b = unless b+              do hPutStrLn stderr ("Test failed: " ++ x)+                 exitFailure++dblTest ::+  String ->+  (Double -> Double -> Double) ->+  (BigFloat -> BigFloat -> (BigFloat, Status)) ->+  Double -> Double -> IO ()+dblTest op opD opBF x y =+  case z1 of+    Left err -> check (lab ("status: " ++ err)) False+    Right a  -> check (lab (show a)) (z == a)+  where+  lab err = unwords [ show x, op, show y, "=", show z, err ]++  z  = opD x y+  z1 = case opBF (bfFromDouble x) (bfFromDouble y) of+        (res,_) ->+          case bfToDouble NearEven res of+            (res1,Ok) -> Right res1+            (_, s)    -> Left ("result: " ++ show s)+++