From af7292b8f8f7e676178046e038120ee8afb0cd8b Mon Sep 17 00:00:00 2001
From: Eduard Burtescu <edy.burt@gmail.com>
Date: Tue, 30 Aug 2016 02:44:14 +0300
Subject: [PATCH] GH #49: Run GVN again after InstCombine.

---
 lib/Transforms/IPO/PassManagerBuilder.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 0b319f6a488b..102b8cc83e7d 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -379,6 +379,8 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   // Run instcombine after redundancy elimination to exploit opportunities
   // opened up by them.
   addInstructionCombiningPass(MPM);
+  if (OptLevel > 1)
+    MPM.add(createGVNPass(DisableGVNLoadPRE));  // Remove redundancies
   addExtensionsToPM(EP_Peephole, MPM);
   MPM.add(createJumpThreadingPass());         // Thread jumps
   MPM.add(createCorrelatedValuePropagationPass());