while (!Worklist.empty()) {
Use *U = Worklist.pop_back_val();
Instruction *I = cast<Instruction>(U->getUser());
- Value *V = U->get();
switch (I->getOpcode()) {
case Instruction::BitCast:
return Attribute::None;
}
- Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
- CallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
- for (CallSite::arg_iterator A = B; A != E; ++A, ++AI) {
- if (A->get() == V) {
- if (AI == AE) {
- assert(F->isVarArg() &&
- "More params than args in non-varargs call.");
- return Attribute::None;
- }
- Captures &= !CS.doesNotCapture(A - B);
- if (SCCNodes.count(&*AI))
- continue;
- if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(A - B))
- return Attribute::None;
- if (!CS.doesNotAccessMemory(A - B))
- IsRead = true;
- }
+ // Note: the callee and the two successor blocks *follow* the argument
+ // operands. This means there is no need to adjust UseIndex to account
+ // for these.
+
+ unsigned UseIndex = std::distance(CS.arg_begin(), U);
+
+ assert(UseIndex < CS.arg_size() && "Non-argument use?");
+ if (UseIndex >= F->arg_size()) {
+ assert(F->isVarArg() && "More params than args in non-varargs call");
+ return Attribute::None;
}
+
+ Captures &= !CS.doesNotCapture(UseIndex);
+ if (!SCCNodes.count(std::next(F->arg_begin(), UseIndex))) {
+ if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(UseIndex))
+ return Attribute::None;
+ if (!CS.doesNotAccessMemory(UseIndex))
+ IsRead = true;
+ }
+
AddUsersToWorklistIfCapturing();
break;
}