diff --git a/ChangeLog.md b/ChangeLog.md --- a/ChangeLog.md +++ b/ChangeLog.md @@ -1,5 +1,9 @@ # Changelog for Posit Numbers +# posit-3.2.0.5 + + * Bug fix for `mkIntRep` to resolve an overflow issue with the fractional part when it rounds up, in anticipation of the 2022 Standard release + # posit-3.2.0.4 * No more Orphan Instances for Storable! diff --git a/README.md b/README.md --- a/README.md +++ b/README.md @@ -1,4 +1,4 @@ -# posit 3.2.0.4 +# posit 3.2.0.5 The [Posit Standard 3.2](https://posithub.org/docs/posit_standard.pdf), where Real numbers are approximated by Maybe Rational. The Posit diff --git a/posit.cabal b/posit.cabal --- a/posit.cabal +++ b/posit.cabal @@ -1,7 +1,7 @@ cabal-version: 1.12 name: posit -version: 3.2.0.4 +version: 3.2.0.5 description: The Posit Number format. Please see the README on GitHub at homepage: https://github.com/waivio/posit#readme bug-reports: https://github.com/waivio/posit/issues diff --git a/src/Posit/Internal/PositC.hs b/src/Posit/Internal/PositC.hs --- a/src/Posit/Internal/PositC.hs +++ b/src/Posit/Internal/PositC.hs @@ -1,7 +1,7 @@ -------------------------------------------------------------------------------------------- -- --- Copyright : (C) 2022 Nathan Waivio +-- Copyright : (C) 2022-2023 Nathan Waivio -- License : BSD3 -- Maintainer : Nathan Waivio -- Stability : Stable @@ -54,7 +54,7 @@ import Data.Int (Int8,Int16,Int32,Int64) -- Import standard Int sizes import Data.DoubleWord (Word128,Int128,Int256,fromHiAndLo,hiWord,loWord,DoubleWord,BinaryWord) -- Import large Int sizes import Data.Word (Word64) -import Data.Bits (Bits(..), (.|.), shiftL, shift, testBit, (.&.), shiftR,FiniteBits) +import Data.Bits (Bits(..), shiftL, shift, testBit, (.&.), shiftR,FiniteBits) -- Import Naturals and Rationals {-@ embed Natural * as int @-} @@ -227,7 +227,9 @@ let (regime', offset) = formRegime @es regime -- offset is the number of binary digits remaining after the regime is formed (exponent', offset') = formExponent @es exponent offset -- offset' is the number of binary digits remaining after the exponent is formed fraction = formFraction @es significand offset' - in regime' .|. exponent' .|. fraction + in regime' + exponent' + fraction -- Previously bad code... + -- Was previously Bitwise OR'd (regime' .|. exponent' .|. fraction), but that failed when an overflow occurs in the fraction: + -- (R @es (6546781215792283740026379393655198304433284092086129578966582736192267592809066457889108741457440782093636999212155773298525238592782299216095867171579 % 6546781215792283740026379393655198304433284092086129578966582736192267592809349109766540184651808314301773368255120142018434513091770786106657055178752)) formRegime :: Integer -> (IntN es, Integer) formRegime power diff --git a/test/TestPosit.hs b/test/TestPosit.hs --- a/test/TestPosit.hs +++ b/test/TestPosit.hs @@ -1,7 +1,7 @@ -------------------------------------------------------------------------------------------- -- | Posit Numbers --- Copyright : (C) 2022 Nathan Waivio +-- Copyright : (C) 2022-2023 Nathan Waivio -- License : BSD3 -- Maintainer : Nathan Waivio -- Stability : Stable @@ -11,23 +11,28 @@ -- --------------------------------------------------------------------------------------------- +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE TypeApplications #-} + import Posit import Posit.Internal.PositC +import Data.Ratio ((%)) -- Import the Rational Numbers ℚ (u+211A), ℚ can get arbitrarily close to Real numbers ℝ (u+211D), used for some of the Transcendental Functions main :: IO () main = do -- - print $ "exp(1)**(pi*sqrt 43): " ++ show (exp(1 :: Posit256) ** (pi * sqrt 43)) -- - print $ "exp(1)**(pi*sqrt 67): " ++ show (exp(1 :: Posit256) ** (pi * sqrt 67)) -- - print $ "exp(1)**(pi*sqrt 163): " ++ show (exp(1 :: Posit256) ** (pi * sqrt 163)) -- - print $ "Machine Alpha Posit8 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit8)) -- succ (Posit int) = Posit (succ int) - print $ "Machine Alpha Posit16 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit16)) -- - print $ "Machine Alpha Posit32 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit32)) -- - print $ "Machine Alpha Posit64 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit64)) -- - print $ "Machine Alpha Posit128 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit128)) -- - print $ "Machine Alpha Posit256 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit256)) -- + print $ "bitwise OR causes problem when fraction overflows Posit256: should be close to 1.0 not 0.5 ==> " ++ show (R @V (6546781215792283740026379393655198304433284092086129578966582736192267592809066457889108741457440782093636999212155773298525238592782299216095867171579 % 6546781215792283740026379393655198304433284092086129578966582736192267592809349109766540184651808314301773368255120142018434513091770786106657055178752)) + print $ "exp(1)**(pi*sqrt 43) :: Posit256 " ++ show (exp(1 :: Posit256) ** (pi * sqrt 43)) -- + print $ "exp(1)**(pi*sqrt 67) :: Posit256 " ++ show (exp(1 :: Posit256) ** (pi * sqrt 67)) -- + print $ "exp(1)**(pi*sqrt 163) :: Posit256 " ++ show (exp(1 :: Posit256) ** (pi * sqrt 163)) -- + print $ "Machine epsilon Posit8 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit8)) -- succ (Posit int) = Posit (succ int) + print $ "Machine epsilon Posit16 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit16)) -- + print $ "Machine epsilon Posit32 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit32)) -- + print $ "Machine epsilon Posit64 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit64)) -- + print $ "Machine epsilon Posit128 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit128)) -- + print $ "Machine epsilon Posit256 ~1.0: " ++ show (1.0 - succ (1.0 :: Posit256)) -- print $ "Does (1 - 1) == 0 ?: " ++ show ((1 - 1) == (0 :: Posit256)) -- [(1 - 1) == zero | zero = 0 :: Posit es, es <- Z .. V] let sqrtTaylor = (funLogDomainReduction funLogTaylor).(/2).(funExp2 funExpTaylor).(/log 2) print $ "sqrt phi using a Taylor algorithm: " ++ show (sqrtTaylor phi)