[InstCombine] Add todos for possible atomicrmw transforms
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354059 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp b/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
index b607c6d..37c4397 100644
--- a/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
@@ -51,6 +51,12 @@
Instruction *InstCombiner::visitAtomicRMWInst(AtomicRMWInst &RMWI) {
+ // TODO: Any atomicrmw op which produces a known result in memory can be
+ // replaced w/an atomicrmw xchg. (see getBinOpAbsorber)
+
+ // TODO: Any atomicrmw xchg with no uses can be converted to a atomic store
+ // if the ordering is compatible.
+
if (!isIdempotentRMW(RMWI))
return nullptr;
