[InstCombine] Remove calloc transformations
Summary: Previous patch does not care if a value is changed between calloc and strlen. This needs to be removed from InstCombine and maybe moved to DSE later after some rework.
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47218
llvm-svn: 333022
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 95e7a9b..0b0dfde 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -3372,39 +3372,11 @@
return NullIndex + 1;
}
-static bool isStringFromCalloc(const Value *Str, const TargetLibraryInfo *TLI) {
- const CallInst *Calloc = dyn_cast<CallInst>(Str);
- if (!Calloc)
- return false;
-
- const Function *InnerCallee = Calloc->getCalledFunction();
- if (!InnerCallee)
- return false;
-
- LibFunc Func;
- if (!TLI->getLibFunc(*InnerCallee, Func) || !TLI->has(Func) ||
- Func != LibFunc_calloc)
- return false;
-
- const ConstantInt *N = dyn_cast<ConstantInt>(Calloc->getOperand(0));
- const ConstantInt *Size = dyn_cast<ConstantInt>(Calloc->getOperand(1));
-
- if (!N || !Size)
- return false;
-
- if (N->isNullValue() || Size->isNullValue())
- return false;
-
- return true;
-}
-
/// If we can compute the length of the string pointed to by
/// the specified pointer, return 'len+1'. If we can't, return 0.
-uint64_t llvm::GetStringLength(const Value *V, const TargetLibraryInfo *TLI, unsigned CharSize) {
+uint64_t llvm::GetStringLength(const Value *V, unsigned CharSize) {
if (!V->getType()->isPointerTy())
return 0;
- if (isStringFromCalloc(V, TLI))
- return 1;
SmallPtrSet<const PHINode*, 32> PHIs;
uint64_t Len = GetStringLengthH(V, PHIs, CharSize);