diff options
| -rw-r--r-- | lib/Transforms/Utils/Local.cpp | 7 | ||||
| -rw-r--r-- | lib/VMCore/Instruction.cpp | 16 |
2 files changed, 12 insertions, 11 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 5e2d237..187ebdc 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -175,13 +175,6 @@ bool llvm::isInstructionTriviallyDead(Instruction *I) { if (!I->mayWriteToMemory()) return true; - if (CallInst *CI = dyn_cast<CallInst>(I)) - if (Function *F = CI->getCalledFunction()) { - unsigned IntrinsicID = F->getIntrinsicID(); -#define GET_SIDE_EFFECT_INFO -#include "llvm/Intrinsics.gen" -#undef GET_SIDE_EFFECT_INFO - } return false; } diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp index feff59d..a368753 100644 --- a/lib/VMCore/Instruction.cpp +++ b/lib/VMCore/Instruction.cpp @@ -197,6 +197,15 @@ bool Instruction::isSameOperationAs(Instruction *I) const { return true; } +// IntrinsicOnlyReadsMemory - Return true if the specified intrinsic doesn't +// have any side-effects or if it only reads memory. +static bool IntrinsicOnlyReadsMemory(unsigned IntrinsicID) { +#define GET_SIDE_EFFECT_INFO +#include "llvm/Intrinsics.gen" +#undef GET_SIDE_EFFECT_INFO + return false; +} + /// mayWriteToMemory - Return true if this instruction may modify memory. /// bool Instruction::mayWriteToMemory() const { @@ -208,11 +217,10 @@ bool Instruction::mayWriteToMemory() const { case Instruction::VAArg: return true; case Instruction::Call: - //if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(this)) { + if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(this)) { // If the intrinsic doesn't write memory, it is safe. - // FIXME: this is obviously supposed to determine which intrinsics - // don't write to memory, but hasn't been implemented yet. - //} + return !IntrinsicOnlyReadsMemory(II->getIntrinsicID()); + } return true; case Instruction::Load: return cast<LoadInst>(this)->isVolatile(); |