Revert earlier change removing setPreservesCFG from instcombine (r221223) and

change LoopSimplifyPass to be !isCFGOnly.  The motivation for the earlier patch
(r221223) was that LoopSimplify is not preserved by instcombine though
setPreservesCFG indicates that it is.  This change fixes the issue
by making setPreservesCFG no longer imply LoopSimplifyPass, and is therefore less
invasive.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221311 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -90,8 +90,7 @@ INITIALIZE_PASS_END(InstCombiner, "instcombine",
                 "Combine redundant instructions", false, false)
 
 void InstCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addPreserved<DominatorTreeWrapperPass>();
-  AU.addPreserved<LoopInfo>();
+  AU.setPreservesCFG();
   AU.addRequired<AssumptionTracker>();
   AU.addRequired<TargetLibraryInfo>();
 }

lib/Transforms/Utils/LoopSimplify.cpp

@@ -778,12 +778,12 @@ namespace {
 
 char LoopSimplify::ID = 0;
 INITIALIZE_PASS_BEGIN(LoopSimplify, "loop-simplify",
-                "Canonicalize natural loops", true, false)
+                "Canonicalize natural loops", false, false)
 INITIALIZE_PASS_DEPENDENCY(AssumptionTracker)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LoopInfo)
 INITIALIZE_PASS_END(LoopSimplify, "loop-simplify",
-                "Canonicalize natural loops", true, false)
+                "Canonicalize natural loops", false, false)
 
 // Publicly exposed interface to pass...
 char &llvm::LoopSimplifyID = LoopSimplify::ID;