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author | Dan Gohman <gohman@apple.com> | 2009-08-19 00:11:12 +0000 |
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committer | Dan Gohman <gohman@apple.com> | 2009-08-19 00:11:12 +0000 |
commit | 107f41fad5f8df734c72cf39a016a7ea0d874388 (patch) | |
tree | 4eb7a844e364bb61f523a4d8cdf78930a3f047c4 | |
parent | 2c9489d6e96d99f77b6c31919805b5e61954deb2 (diff) | |
download | llvm-107f41fad5f8df734c72cf39a016a7ea0d874388.tar.gz llvm-107f41fad5f8df734c72cf39a016a7ea0d874388.tar.bz2 llvm-107f41fad5f8df734c72cf39a016a7ea0d874388.tar.xz |
Fix SimplifyLibcalls and ValueTracking to check mayBeOverridden
before performing optimizations based on constant string values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79384 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Analysis/ValueTracking.cpp | 3 | ||||
-rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 3 | ||||
-rw-r--r-- | test/Transforms/SimplifyLibCalls/weak-symbols.ll | 26 |
3 files changed, 30 insertions, 2 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index 604d10c68b..3ab10c55d8 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -1061,7 +1061,8 @@ bool llvm::GetConstantStringInfo(Value *V, std::string &Str, uint64_t Offset, // variable that is a constant and is initialized. The referenced constant // initializer is the array that we'll use for optimization. GlobalVariable* GV = dyn_cast<GlobalVariable>(V); - if (!GV || !GV->isConstant() || !GV->hasInitializer()) + if (!GV || !GV->isConstant() || !GV->hasInitializer() || + GV->mayBeOverridden()) return false; Constant *GlobalInit = GV->getInitializer(); diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 02b26bdac2..761c309c20 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -438,7 +438,8 @@ static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) { // variable that is a constant and is initialized. The referenced constant // initializer is the array that we'll use for optimization. GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0)); - if (!GV || !GV->isConstant() || !GV->hasInitializer()) + if (!GV || !GV->isConstant() || !GV->hasInitializer() || + GV->mayBeOverridden()) return 0; Constant *GlobalInit = GV->getInitializer(); diff --git a/test/Transforms/SimplifyLibCalls/weak-symbols.ll b/test/Transforms/SimplifyLibCalls/weak-symbols.ll new file mode 100644 index 0000000000..970ee0ddf1 --- /dev/null +++ b/test/Transforms/SimplifyLibCalls/weak-symbols.ll @@ -0,0 +1,26 @@ +; RUN: llvm-as < %s | opt -simplify-libcalls | llvm-dis | FileCheck %s +; PR4738 + +; SimplifyLibcalls shouldn't assume anything about weak symbols. + +@real_init = weak_odr constant [2 x i8] c"y\00" +@fake_init = weak constant [2 x i8] c"y\00" +@.str = private constant [2 x i8] c"y\00" + +; CHECK: define i32 @foo +; CHECK: call i32 @strcmp +define i32 @foo() nounwind { +entry: + %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @fake_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly + ret i32 %t0 +} + +; CHECK: define i32 @bar +; CHECK: ret i32 0 +define i32 @bar() nounwind { +entry: + %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @real_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly + ret i32 %t0 +} + +declare i32 @strcmp(i8*, i8*) nounwind readonly |