diff --git a/llvm-general.cabal b/llvm-general.cabal
--- a/llvm-general.cabal
+++ b/llvm-general.cabal
@@ -1,5 +1,5 @@
 name: llvm-general
-version: 3.2.6.0
+version: 3.2.6.1
 license: BSD3
 license-file: LICENSE
 author: Benjamin S.Scarlet <fgthb0@greynode.net>
@@ -16,7 +16,7 @@
 	handles almost all of the stateful complexities of using the LLVM API to build IR; and it supports moving IR not
 	only from Haskell into LLVM C++ objects, but the other direction - from LLVM C++ into Haskell.
   .
-  For haddock, see <http://bscarlet.github.io/llvm-general/3.2.6.0/doc/html/llvm-general/index.html>.
+  For haddock, see <http://bscarlet.github.io/llvm-general/3.2.6.1/doc/html/llvm-general/index.html>.
 extra-source-files:
   src/LLVM/General/Internal/FFI/Analysis.h
   src/LLVM/General/Internal/FFI/Function.h
@@ -37,7 +37,7 @@
   type: git
   location: git://github.com/bscarlet/llvm-general.git
   branch: llvm-3.2
-  tag: v3.2.6.0
+  tag: v3.2.6.1
 
 flag shared-llvm
   description: link against llvm shared rather than static library
@@ -221,6 +221,7 @@
     LLVM.General.Test.Global
     LLVM.General.Test.InlineAssembly
     LLVM.General.Test.Instructions
+    LLVM.General.Test.Instrumentation
     LLVM.General.Test.Linking
     LLVM.General.Test.Metadata
     LLVM.General.Test.Module
diff --git a/src/LLVM/General/PrettyPrint.hs b/src/LLVM/General/PrettyPrint.hs
--- a/src/LLVM/General/PrettyPrint.hs
+++ b/src/LLVM/General/PrettyPrint.hs
@@ -4,6 +4,7 @@
   #-}
 -- | Tools for printing out AST.'LLVM.General.AST.Module' code so that it's actually useful.
 module LLVM.General.PrettyPrint (
+  PrettyShow(..),
   showPretty,
   showPrettyEx,
   PrefixScheme(..),
@@ -102,6 +103,7 @@
 basePrefixScheme :: PrefixScheme
 basePrefixScheme = PrefixScheme $ Map.fromList [
   ("Data.Maybe", Nothing),
+  ("Data.Either", Nothing),
   ("Data.Map", Just "Map"),
   ("Data.Set", Just "Set")
  ]
diff --git a/test/LLVM/General/Test/Instrumentation.hs b/test/LLVM/General/Test/Instrumentation.hs
new file mode 100644
--- /dev/null
+++ b/test/LLVM/General/Test/Instrumentation.hs
@@ -0,0 +1,139 @@
+module LLVM.General.Test.Instrumentation where
+
+import Test.Framework
+import Test.Framework.Providers.HUnit
+import Test.HUnit
+
+import LLVM.General.Test.Support
+
+import Control.Monad.Error
+import Data.Functor
+import qualified Data.List as List
+import qualified Data.Set as Set
+import qualified Data.Map as Map
+
+import LLVM.General.Module
+import LLVM.General.Context
+import LLVM.General.PassManager
+import LLVM.General.Transforms
+import LLVM.General.Target
+
+import LLVM.General.AST as A
+import LLVM.General.AST.Type
+import LLVM.General.AST.Name
+import LLVM.General.AST.AddrSpace
+import LLVM.General.AST.DataLayout
+import qualified LLVM.General.AST.IntegerPredicate as IPred
+import qualified LLVM.General.AST.Linkage as L
+import qualified LLVM.General.AST.Visibility as V
+import qualified LLVM.General.AST.CallingConvention as CC
+import qualified LLVM.General.AST.Attribute as A
+import qualified LLVM.General.AST.Global as G
+import qualified LLVM.General.AST.Constant as C
+
+instrument :: PassSetSpec -> A.Module -> IO A.Module
+instrument s m = withContext $ \context -> withModuleFromAST' context m $ \mIn' -> do
+  withPassManager s $ \pm -> runPassManager pm mIn'
+  moduleAST mIn'
+
+ast = do
+ dl <- withDefaultTargetMachine getTargetMachineDataLayout
+ return $ Module "<string>" (Just dl) Nothing [
+  GlobalDefinition $ Function L.External V.Default CC.C [] (IntegerType 32) (Name "foo") ([
+      Parameter (IntegerType 128) (Name "x") []
+     ],False)
+   [] 
+   Nothing 0         
+   [
+    BasicBlock (UnName 0) [] (Do $ Br (Name "checkDone") []),
+    BasicBlock (Name "checkDone") [
+      UnName 1 := Phi {
+       type' = IntegerType 128,
+       incomingValues = [
+        (LocalReference (Name "x"), UnName 0),
+        (LocalReference (Name "x'"), Name "even"),
+        (LocalReference (Name "x''"), Name "odd")
+       ],
+       metadata = []
+      },
+      Name "count" := Phi {
+       type' = IntegerType 32,
+       incomingValues = [
+        (ConstantOperand (C.Int 32 1), UnName 0),
+        (LocalReference (Name "count'"), Name "even"),
+        (LocalReference (Name "count'"), Name "odd")
+       ],
+       metadata = []
+      },
+      Name "count'" := Add False False (LocalReference (Name "count")) (ConstantOperand (C.Int 32 1)) [],
+      Name "is one" := ICmp IPred.EQ (LocalReference (UnName 1)) (ConstantOperand (C.Int 128 1)) []
+    ] (
+      Do $ CondBr (LocalReference (Name "is one")) (Name "done") (Name "checkOdd") []
+    ),
+    BasicBlock (Name "checkOdd") [
+      Name "is odd" := Trunc (LocalReference (UnName 1)) (IntegerType 1) []
+    ] (
+     Do $ CondBr (LocalReference (Name "is odd")) (Name "odd") (Name "even") []
+    ),
+    BasicBlock (Name "even") [
+      Name "x'" := UDiv True (LocalReference (UnName 1)) (ConstantOperand (C.Int 128 2)) []
+    ] (
+      Do $ Br (Name "checkDone") []
+    ),
+    BasicBlock (Name "odd") [
+      UnName 2 := Mul False False (LocalReference (UnName 1)) (ConstantOperand (C.Int 128 3)) [],
+      Name "x''" := Add False False (LocalReference (UnName 2)) (ConstantOperand (C.Int 128 1)) []
+    ] (
+      Do $ Br (Name "checkDone") []
+    ),
+    BasicBlock (Name "done") [
+    ] (
+      Do $ Ret (Just (LocalReference (Name "count'"))) []
+    )
+   ],
+  GlobalDefinition $ Function L.External V.Default CC.C [] (IntegerType 32) (Name "main") ([
+      Parameter (IntegerType 32) (Name "argc") [],
+      Parameter (PointerType (PointerType (IntegerType 8) (AddrSpace 0)) (AddrSpace 0)) (Name "argv") []
+     ],False)
+   [] 
+   Nothing 0         
+   [
+    BasicBlock (UnName 0) [
+      UnName 1 := Call {
+        isTailCall = False,
+        callingConvention = CC.C,
+        returnAttributes = [],
+        function = Right (ConstantOperand (C.GlobalReference (Name "foo"))),
+        arguments = [
+         (ConstantOperand (C.Int 128 9491828328), [])
+        ],
+        functionAttributes = [],
+        metadata = []
+      }
+    ] (
+      Do $ Ret (Just (LocalReference (UnName 1))) []
+    )
+   ]
+  ]
+
+tests = testGroup "Instrumentation" [
+  testGroup "basic" [
+    testCase n $ do
+      triple <- getDefaultTargetTriple
+      withTargetLibraryInfo triple $ \tli -> do
+        Right dl <- runErrorT $ withDefaultTargetMachine getTargetMachineDataLayout
+        Right ast <- runErrorT ast
+        ast' <- instrument (defaultPassSetSpec { transforms = [p], dataLayout = Just dl, targetLibraryInfo = Just tli }) ast
+        let names ast = [ n | GlobalDefinition d <- moduleDefinitions ast, Name n <- return (G.name d) ]
+        (names ast') `List.intersect` (names ast) @?= names ast
+    | (n,p) <- [
+     ("EdgeProfiler", EdgeProfiler),
+     ("OptimalEdgeProfiler", OptimalEdgeProfiler),
+     ("PathProfiler", PathProfiler),
+     ("GCOVProfiler", defaultGCOVProfiler),
+     ("AddressSanitizer", defaultAddressSanitizer),
+     ("ThreadSanitizer", defaultThreadSanitizer),
+     ("BoundsChecking", BoundsChecking)
+    ]
+   ]
+ ]
diff --git a/test/LLVM/General/Test/PrettyPrint.hs b/test/LLVM/General/Test/PrettyPrint.hs
--- a/test/LLVM/General/Test/PrettyPrint.hs
+++ b/test/LLVM/General/Test/PrettyPrint.hs
@@ -75,7 +75,8 @@
     showPretty ast @?= s,
   testCase "imports" $ do
     imports defaultPrefixScheme @?= 
-      "import qualified Data.Map as Map\n\
+      "import Data.Either\n\
+      \import qualified Data.Map as Map\n\
       \import Data.Maybe\n\
       \import qualified Data.Set as Set\n\
       \import qualified LLVM.General.AST as A\n\
diff --git a/test/LLVM/General/Test/Support.hs b/test/LLVM/General/Test/Support.hs
--- a/test/LLVM/General/Test/Support.hs
+++ b/test/LLVM/General/Test/Support.hs
@@ -11,6 +11,7 @@
 import LLVM.General.Context
 import LLVM.General.Module
 import LLVM.General.Diagnostic
+import LLVM.General.PrettyPrint
 
 class FailInIO f where
   errorToString :: f -> String
@@ -27,10 +28,17 @@
 withModuleFromString' c s f  = failInIO $ withModuleFromString c s f
 withModuleFromAST' c a f = failInIO $ withModuleFromAST c a f
 
+assertEqPretty :: (Eq a, PrettyShow a) => a -> a -> Assertion
+assertEqPretty actual expected = do
+  let showPretty = showPrettyEx 80 "  " shortPrefixScheme
+  assertBool 
+   ("expected: " ++ showPretty expected ++ "\n" ++ "but got: " ++ showPretty actual ++ "\n")
+   (expected == actual)
+
 strCheckC mAST mStr mStrCanon = withContext $ \context -> do
   a <- withModuleFromString' context mStr moduleAST
   s <- withModuleFromAST' context mAST moduleString
-  (a,s) @?= (mAST, mStrCanon)
+  (a,s) `assertEqPretty` (mAST, mStrCanon)
 
 strCheck mAST mStr = strCheckC mAST mStr mStr