[llvm] r221223 - Remove setPreservesCFG from instcombine. The pass, in particular, does not

[Mark Heffernan]

Author: meheff
Date: Mon Nov  3 19:51:01 2014
New Revision: 221223

URL: http://llvm.org/viewvc/llvm-project?rev=221223&view=rev
Log:
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.


Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=221223&r1=221222&r2=221223&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Mon Nov  3 19:51:01 2014
@@ -90,7 +90,8 @@ INITIALIZE_PASS_END(InstCombiner, "instc
                 "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>();
 }