Cleanup comments and argument types related to my previous replaceCongruentPhis checkin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147709 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index 0c4bb82..26ae22b 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -1558,8 +1558,8 @@
return true;
}
-/// Sort Phis by integer width for replaceCongruentIVs.
-static bool width_descending(PHINode *lhs, PHINode *rhs) {
+/// Sort values by integer width for replaceCongruentIVs.
+static bool width_descending(Value *lhs, Value *rhs) {
// Put pointers at the back and make sure pointer < pointer = false.
if (!lhs->getType()->isIntegerTy() || !rhs->getType()->isIntegerTy())
return rhs->getType()->isIntegerTy() && !lhs->getType()->isIntegerTy();
@@ -1632,8 +1632,9 @@
// Replacing the congruent phi is sufficient because acyclic redundancy
// elimination, CSE/GVN, should handle the rest. However, once SCEV proves
// that a phi is congruent, it's often the head of an IV user cycle that
- // is isomorphic with the original phi. So it's worth eagerly cleaning up
- // the common case of a single IV increment.
+ // is isomorphic with the original phi. It's worth eagerly cleaning up the
+ // common case of a single IV increment so that DeleteDeadPHIs can remove
+ // cycles that had postinc uses.
const SCEV *TruncExpr = SE.getTruncateOrNoop(SE.getSCEV(OrigInc),
IsomorphicInc->getType());
if (OrigInc != IsomorphicInc