From 44e875ad5b2ce26826dd53f9e7d1a71436c86212 Mon Sep 17 00:00:00 2001
From: Kuba Brecka <kuba.brecka@gmail.com>
Date: Mon, 7 Nov 2016 19:09:56 +0000
Subject: [tsan] Cast floating-point types correctly when instrumenting atomic
 accesses, LLVM part

Although rare, atomic accesses to floating-point types seem to be valid, i.e. `%a = load atomic float ...`. The TSan instrumentation pass however tries to emit inttoptr, which is incorrect, we should use a bitcast here. Anyway, IRBuilder already has a convenient helper function for this.

Differential Revision: https://reviews.llvm.org/D26266

llvm-svn: 286135
---
 .../Transforms/Instrumentation/ThreadSanitizer.cpp | 23 ++++++----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

(limited to 'llvm/lib/Transforms')

diff --git a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
index 41d0b53672d..355f69c9aae 100644
--- a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
@@ -549,11 +549,6 @@ bool ThreadSanitizer::instrumentMemIntrinsic(Instruction *I) {
   return false;
 }
 
-static Value *createIntOrPtrToIntCast(Value *V, Type* Ty, IRBuilder<> &IRB) {
-  return isa<PointerType>(V->getType()) ?
-    IRB.CreatePtrToInt(V, Ty) : IRB.CreateIntCast(V, Ty, false);
-}
-
 // Both llvm and ThreadSanitizer atomic operations are based on C++11/C1x
 // standards.  For background see C++11 standard.  A slightly older, publicly
 // available draft of the standard (not entirely up-to-date, but close enough
@@ -576,15 +571,9 @@ bool ThreadSanitizer::instrumentAtomic(Instruction *I, const DataLayout &DL) {
     Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
                      createOrdering(&IRB, LI->getOrdering())};
     Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
-    if (Ty == OrigTy) {
-      Instruction *C = CallInst::Create(TsanAtomicLoad[Idx], Args);
-      ReplaceInstWithInst(I, C);
-    } else {
-      // We are loading a pointer, so we need to cast the return value.
-      Value *C = IRB.CreateCall(TsanAtomicLoad[Idx], Args);
-      Instruction *Cast = CastInst::Create(Instruction::IntToPtr, C, OrigTy);
-      ReplaceInstWithInst(I, Cast);
-    }
+    Value *C = IRB.CreateCall(TsanAtomicLoad[Idx], Args);
+    Value *Cast = IRB.CreateBitOrPointerCast(C, OrigTy);
+    I->replaceAllUsesWith(Cast);
   } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
     Value *Addr = SI->getPointerOperand();
     int Idx = getMemoryAccessFuncIndex(Addr, DL);
@@ -595,7 +584,7 @@ bool ThreadSanitizer::instrumentAtomic(Instruction *I, const DataLayout &DL) {
     Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
     Type *PtrTy = Ty->getPointerTo();
     Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
-                     createIntOrPtrToIntCast(SI->getValueOperand(), Ty, IRB),
+                     IRB.CreateBitOrPointerCast(SI->getValueOperand(), Ty),
                      createOrdering(&IRB, SI->getOrdering())};
     CallInst *C = CallInst::Create(TsanAtomicStore[Idx], Args);
     ReplaceInstWithInst(I, C);
@@ -626,9 +615,9 @@ bool ThreadSanitizer::instrumentAtomic(Instruction *I, const DataLayout &DL) {
     Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
     Type *PtrTy = Ty->getPointerTo();
     Value *CmpOperand =
-      createIntOrPtrToIntCast(CASI->getCompareOperand(), Ty, IRB);
+      IRB.CreateBitOrPointerCast(CASI->getCompareOperand(), Ty);
     Value *NewOperand =
-      createIntOrPtrToIntCast(CASI->getNewValOperand(), Ty, IRB);
+      IRB.CreateBitOrPointerCast(CASI->getNewValOperand(), Ty);
     Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
                      CmpOperand,
                      NewOperand,
-- 
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