Revert "Simplify blockaddress usage before giving up in MergeBlockIntoPredecessor"

This reverts commit f976cf4cca0794267f28b54e468007fd476d37d9.

I am reverting this because it causes break in a few bots and its going
to take me sometime to look at this.

llvm-svn: 334993

1 files changed, 1 insertions, 8 deletions

diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 4b89b0435e0..59837042550 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -119,14 +119,7 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, DominatorTree *DT,
                                      LoopInfo *LI,
                                      MemoryDependenceResults *MemDep) {
   // Don't merge away blocks who have their address taken.
-  if (BB->hasAddressTaken()) {
-    // If the block has its address taken, it may be a tree of dead constants
-    // hanging off of it.  These shouldn't keep the block alive.
-    BlockAddress *BA = BlockAddress::get(BB);
-    BA->removeDeadConstantUsers();
-    if (!BA->use_empty())
-      return false;
-  }
+  if (BB->hasAddressTaken()) return false;
 
   // Can't merge if there are multiple predecessors, or no predecessors.
   BasicBlock *PredBB = BB->getUniquePredecessor();