From 524c48536bc3f7148c28978bdeb3d046382cab2c Mon Sep 17 00:00:00 2001
From: Daniel Berlin <dberlin@dberlin.org>
Date: Sun, 12 Feb 2017 23:24:45 +0000
Subject: [PATCH] NewGVN: Reverse order of congruence class elimination to
 maximize trivial deadness

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294926 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/NewGVN.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/Scalar/NewGVN.cpp b/lib/Transforms/Scalar/NewGVN.cpp
index 25455c75b4e..ab195e4000c 100644
--- a/lib/Transforms/Scalar/NewGVN.cpp
+++ b/lib/Transforms/Scalar/NewGVN.cpp
@@ -2059,7 +2059,7 @@ void NewGVN::convertDenseToLoadsAndStores(
 }
 
 static void patchReplacementInstruction(Instruction *I, Value *Repl) {
-    auto *ReplInst = dyn_cast<Instruction>(Repl);
+  auto *ReplInst = dyn_cast<Instruction>(Repl);
   if (!ReplInst)
     return;
 
@@ -2220,7 +2220,7 @@ bool NewGVN::eliminateInstructions(Function &F) {
     }
   }
 
-  for (CongruenceClass *CC : CongruenceClasses) {
+  for (CongruenceClass *CC : reverse(CongruenceClasses)) {
     // Track the equivalent store info so we can decide whether to try
     // dead store elimination.
     SmallVector<ValueDFS, 8> PossibleDeadStores;
-- 
2.50.1