From 4be7d294f8045f08bcdbd74f1886ea8121a77022 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Thu, 3 Jul 2008 06:48:21 +0000
Subject: [PATCH] Reconstruct dom info, if loop is unswitched.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53086 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/LoopUnswitch.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index f57b7bb5194..02dac92aa13 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -113,8 +113,8 @@ namespace {
       AU.addRequiredID(LCSSAID);
       AU.addPreservedID(LCSSAID);
       // FIXME: Loop Unswitch does not preserve dominator info in all cases.
-      // AU.addPreserved<DominatorTree>();
-      // AU.addPreserved<DominanceFrontier>();
+      AU.addPreserved<DominatorTree>();
+      AU.addPreserved<DominanceFrontier>();
     }
 
   private:
@@ -206,7 +206,6 @@ bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
   DT = getAnalysisToUpdate<DominatorTree>();
   currentLoop = L;
   bool Changed = false;
-
   do {
     assert(currentLoop->isLCSSAForm());
     redoLoop = false;
@@ -459,7 +458,13 @@ bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val){
   } else {
     UnswitchNontrivialCondition(LoopCond, Val, currentLoop);
   }
- 
+
+  // FIXME: Reconstruct dom info, because it is not preserved properly.
+  Function *F = loopHeader->getParent();
+  if (DT)
+    DT->runOnFunction(*F);
+  if (DF)
+    DF->runOnFunction(*F);
   return true;
 }