From 4ab32e0db95b14e7d316a2a965a134ae992b8578 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 941efb210d1c..6d0071d4f60a 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -342,6 +342,8 @@ 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());