// to avoid wrong assumptions of sort "if A is executed and B post-dominates
// A, then B is also executed". This is not true is there is an implicit
// control flow instruction (e.g. a guard) between them.
- //
- // TODO: Currently, isGuaranteedToTransferExecutionToSuccessor returns false
- // for volatile stores and loads because they can trap. The discussion on
- // whether or not it is correct is still ongoing. We might want to get rid
- // of this logic in the future. Anyways, trapping instructions shouldn't
- // introduce implicit control flow, so we explicitly allow them here. This
- // must be removed once isGuaranteedToTransferExecutionToSuccessor is fixed.
- if (isGuaranteedToTransferExecutionToSuccessor(Insn))
- return false;
- if (isa<LoadInst>(Insn)) {
- assert(cast<LoadInst>(Insn)->isVolatile() &&
- "Non-volatile load should transfer execution to successor!");
- return false;
- }
- if (isa<StoreInst>(Insn)) {
- assert(cast<StoreInst>(Insn)->isVolatile() &&
- "Non-volatile store should transfer execution to successor!");
- return false;
- }
- return true;
+ return !isGuaranteedToTransferExecutionToSuccessor(Insn);
}
bool MemoryWriteTracking::isSpecialInstruction(