================
@@ -970,6 +971,19 @@ ModRefInfo BasicAAResult::getModRefInfo(const CallBase
*Call,
}
ModRefInfo Result = ArgMR | OtherMR;
+
+ // Refine writes to errno memory. We can safely exclude the errno location if
+ // the given memory location is an alloca, the size of the memory access is
+ // larger than `sizeof(int)` or if TBAA proves it does not alias errno.
+ if ((ErrnoMR | OtherMR) != OtherMR) {
+ bool IsLocSizeUnknown = Loc.Size == MemoryLocation::UnknownSize;
+ if (ErrnoMR == ModRefInfo::Mod && !isa<AllocaInst>(Object) &&
+ (IsLocSizeUnknown ||
+ (!IsLocSizeUnknown && Loc.Size.getValue() <= sizeof(int))) &&
+ AAQI.AAR.aliasErrno(Loc, Call->getModule()) != AliasResult::NoAlias)
----------------
nikic wrote:
Also, possibly these extra checks should be in BasicAA::aliasErrno instead?
https://github.com/llvm/llvm-project/pull/125258
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
