if (CS.getCalledFunction() && SCCNodes.count(CS.getCalledFunction()))
continue;
FunctionModRefBehavior MRB = AAR.getModRefBehavior(CS);
- // If the call doesn't access arbitrary memory, we may be able to
- // figure out something.
- if (AliasAnalysis::onlyAccessesArgPointees(MRB)) {
- // If the call does access argument pointees, check each argument.
- if (AliasAnalysis::doesAccessArgPointees(MRB))
- // Check whether all pointer arguments point to local memory, and
- // ignore calls that only access local memory.
- for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
- CI != CE; ++CI) {
- Value *Arg = *CI;
- if (Arg->getType()->isPointerTy()) {
- AAMDNodes AAInfo;
- I->getAAMetadata(AAInfo);
-
- MemoryLocation Loc(Arg, MemoryLocation::UnknownSize, AAInfo);
- if (!AAR.pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
- if (MRB & MRI_Mod)
- // Writes non-local memory. Give up.
- return MAK_MayWrite;
- if (MRB & MRI_Ref)
- // Ok, it reads non-local memory.
- ReadsMemory = true;
- }
- }
- }
+
+ // If the call doesn't access memory, we're done.
+ if (!(MRB & MRI_ModRef))
continue;
+
+ if (!AliasAnalysis::onlyAccessesArgPointees(MRB)) {
+ // The call could access any memory. If that includes writes, give up.
+ if (MRB & MRI_Mod)
+ return MAK_MayWrite;
+ // If it reads, note it.
+ if (MRB & MRI_Ref)
+ ReadsMemory = true;
+ continue;
+ }
+
+ // Check whether all pointer arguments point to local memory, and
+ // ignore calls that only access local memory.
+ for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
+ CI != CE; ++CI) {
+ Value *Arg = *CI;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+
+ AAMDNodes AAInfo;
+ I->getAAMetadata(AAInfo);
+ MemoryLocation Loc(Arg, MemoryLocation::UnknownSize, AAInfo);
+
+ // Skip accesses to local or constant memory as they don't impact the
+ // externally visible mod/ref behavior.
+ if (AAR.pointsToConstantMemory(Loc, /*OrLocal=*/true))
+ continue;
+
+ if (MRB & MRI_Mod)
+ // Writes non-local memory. Give up.
+ return MAK_MayWrite;
+ if (MRB & MRI_Ref)
+ // Ok, it reads non-local memory.
+ ReadsMemory = true;
}
- // The call could access any memory. If that includes writes, give up.
- if (MRB & MRI_Mod)
- return MAK_MayWrite;
- // If it reads, note it.
- if (MRB & MRI_Ref)
- ReadsMemory = true;
continue;
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
// Ignore non-volatile loads from local memory. (Atomic is okay here.)