Add a peephole to fuse cmpxchg w/ later cmp+branch.
The cmpxchg instruction already sets ZF for comparing the return value
vs the expected value. So there is no need to compare eq again.
Lots of pexes-in-the-wild have this pattern. Some compare against
a constant, some compare against a variable.
BUG=https://code.google.com/p/nativeclient/issues/detail?id=3882
R=stichnot@chromium.org
Review URL: https://codereview.chromium.org/413903002
diff --git a/src/IceTargetLowering.cpp b/src/IceTargetLowering.cpp
index 05ae121..2a9b8c4 100644
--- a/src/IceTargetLowering.cpp
+++ b/src/IceTargetLowering.cpp
@@ -38,12 +38,12 @@
Inst->updateVars(getNode());
}
-void LoweringContext::skipDeleted(InstList::iterator &I) {
+void LoweringContext::skipDeleted(InstList::iterator &I) const {
while (I != End && (*I)->isDeleted())
++I;
}
-void LoweringContext::advance(InstList::iterator &I) {
+void LoweringContext::advance(InstList::iterator &I) const {
if (I != End) {
++I;
skipDeleted(I);
