From: Bill Wendling <isanbard@gmail.com>
Date: Fri, 2 May 2008 00:43:20 +0000 (+0000)
Subject: Porting r50563 from Tak to mainline.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=643310da6d6a9e8cb64575246483f63897fbbcf4;p=oota-llvm.git

Porting r50563 from Tak to mainline.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50564 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index da6f076a9a6..a6bd9ff20a9 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -1124,6 +1124,11 @@ bool LoopIndexSplit::safeSplitCondition(SplitInfo &SD) {
   BasicBlock *Succ0 = SplitTerminator->getSuccessor(0);
   BasicBlock *Succ1 = SplitTerminator->getSuccessor(1);
 
+  // If split block does not dominate the latch then this is not a diamond.
+  // Such loop may not benefit from index split.
+  if (!DT->dominates(SplitCondBlock, Latch))
+    return false;
+
   // Finally this split condition is safe only if merge point for
   // split condition branch is loop latch. This check along with previous
   // check, to ensure that exit condition is in either loop latch or header,