Keep CodeGenPrepare from preserving the domtree.

CGP modifies the domtree in some cases, so saying that it preserves the
domtree is a lie. We'll be able to selectively preserve it with the new
pass manager.

Differential Revision: http://reviews.llvm.org/D16893

llvm-svn: 264099

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 4932173e103..8ba52c424a6 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -158,7 +158,7 @@ class TypePromotionTransaction;
     const char *getPassName() const override { return "CodeGen Prepare"; }
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.addPreserved<DominatorTreeWrapperPass>();
+      // FIXME: When we can selectively preserve passes, preserve the domtree.
       AU.addRequired<TargetLibraryInfoWrapperPass>();
       AU.addRequired<TargetTransformInfoWrapperPass>();
     }
@@ -5277,6 +5277,7 @@ bool CodeGenPrepare::optimizeBlock(BasicBlock &BB, bool& ModifiedDT) {
     for (auto &I : reverse(BB)) {
       if (makeBitReverse(I, *DL, *TLI)) {
         MadeBitReverse = MadeChange = true;
+        ModifiedDT = true;
         break;
       }
     }