From: Philip Reames <listmail@philipreames.com>
Date: Thu, 14 Feb 2019 20:48:36 +0000 (+0000)
Subject: [InstCombine] Add todos for possible atomicrmw transforms
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=db57ef62382cfe50d7bd4d038aa54e3a98abae1d;p=platform%2Fupstream%2Fllvm.git

[InstCombine] Add todos for possible atomicrmw transforms

llvm-svn: 354059
---

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
index b607c6d..37c4397 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
@@ -51,6 +51,12 @@ bool isIdempotentRMW(AtomicRMWInst& RMWI) {
 
 
 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;