From 2e25042a937e0e2762c8ef35a3a30ec8f9930406 Mon Sep 17 00:00:00 2001
From: Mark Heffernan <meheff@google.com>
Date: Tue, 4 Nov 2014 01:51:01 +0000
Subject: [PATCH] Remove setPreservesCFG from instcombine.  The pass, in
 particular, does not preserve LoopSimplify because instcombine may replace
 branch predicates with undef which loop simplify then replaces with always
 exit.  Replace setPreservesCFG with the more constrained preservation of
 DomTree and LoopInfo.

llvm-svn: 221223
---
 llvm/lib/Transforms/InstCombine/InstructionCombining.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 5a0b01e..4b7f841 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -90,7 +90,8 @@ INITIALIZE_PASS_END(InstCombiner, "instcombine",
                 "Combine redundant instructions", false, false)
 
 void InstCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesCFG();
+  AU.addPreserved<DominatorTreeWrapperPass>();
+  AU.addPreserved<LoopInfo>();
   AU.addRequired<AssumptionTracker>();
   AU.addRequired<TargetLibraryInfo>();
 }
-- 
2.7.4