Finish making AliasAnalysis aware of the fact that most atomic intrinsics only dereference their arguments, and enhance
BasicAA to make use of this fact when computing ModRef info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63718 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 2571492..3e46fcc 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -150,6 +150,27 @@
AliasAnalysis::ModRefBehavior
AliasAnalysis::getModRefBehavior(Function *F,
std::vector<PointerAccessInfo> *Info) {
+ if (F->isIntrinsic()) {
+ switch (F->getIntrinsicID()) {
+ case Intrinsic::atomic_cmp_swap:
+ case Intrinsic::atomic_load_add:
+ case Intrinsic::atomic_load_and:
+ case Intrinsic::atomic_load_max:
+ case Intrinsic::atomic_load_min:
+ case Intrinsic::atomic_load_nand:
+ case Intrinsic::atomic_load_or:
+ case Intrinsic::atomic_load_sub:
+ case Intrinsic::atomic_load_umax:
+ case Intrinsic::atomic_load_umin:
+ case Intrinsic::atomic_load_xor:
+ case Intrinsic::atomic_swap:
+ // CAS and related intrinsics only access their arguments.
+ return AliasAnalysis::AccessesArguments;
+ default:
+ break;
+ }
+ }
+
if (F->doesNotAccessMemory())
// Can't do better than this.
return DoesNotAccessMemory;