From f4b76be9368f8fdafae2513d89b8a3d17ea12eb7 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221223 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/InstCombine/InstructionCombining.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 5a0b01eca5c..4b7f841e2cd 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/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>();
 }
-- 
2.34.1