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-rw-r--r--lib/VMCore/Instruction.cpp35
1 files changed, 3 insertions, 32 deletions
diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index a5500e6..3fabfd0 100644
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -374,37 +374,6 @@ bool Instruction::isCommutative(unsigned op) {
}
}
-// Code here matches isMalloc from MemoryBuiltins, which is not in VMCore.
-static bool isMalloc(const Value* I) {
- const CallInst *CI = dyn_cast<CallInst>(I);
- if (!CI) {
- const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
- if (!BCI) return false;
-
- CI = dyn_cast<CallInst>(BCI->getOperand(0));
- }
-
- if (!CI)
- return false;
- Function *Callee = CI->getCalledFunction();
- if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "malloc")
- return false;
-
- // Check malloc prototype.
- // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
- // attribute will exist.
- const FunctionType *FTy = Callee->getFunctionType();
- if (FTy->getNumParams() != 1)
- return false;
- if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
- if (ITy->getBitWidth() != 32 && ITy->getBitWidth() != 64)
- return false;
- return true;
- }
-
- return false;
-}
-
bool Instruction::isSafeToSpeculativelyExecute() const {
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (Constant *C = dyn_cast<Constant>(getOperand(i)))
@@ -430,7 +399,9 @@ bool Instruction::isSafeToSpeculativelyExecute() const {
case Load: {
if (cast<LoadInst>(this)->isVolatile())
return false;
- if (isa<AllocaInst>(getOperand(0)) || isMalloc(getOperand(0)))
+ // Note that it is not safe to speculate into a malloc'd region because
+ // malloc may return null.
+ if (isa<AllocaInst>(getOperand(0)))
return true;
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
return !GV->hasExternalWeakLinkage();
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