From 0c0f7c935bc4c6de74bd4025ceca7278e128f48d Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Mon, 10 Sep 2007 23:34:06 +0000
Subject: [PATCH] Swap exit condition operands if it works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41817 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/LoopIndexSplit.cpp | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 3a046655d5e..0f55a9100c3 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -328,14 +328,24 @@ void LoopIndexSplit::findLoopConditionals() {
   if (!CI)
     return;
 
-  // FIXME 
+  // FIXME
+  if (CI->getPredicate() == ICmpInst::ICMP_EQ
+      || CI->getPredicate() == ICmpInst::ICMP_NE)
+    return;
+
   if (CI->getPredicate() == ICmpInst::ICMP_SGT
       || CI->getPredicate() == ICmpInst::ICMP_UGT
       || CI->getPredicate() == ICmpInst::ICMP_SGE
-      || CI->getPredicate() == ICmpInst::ICMP_UGE
-      || CI->getPredicate() == ICmpInst::ICMP_EQ
-      || CI->getPredicate() == ICmpInst::ICMP_NE)
-    return;
+      || CI->getPredicate() == ICmpInst::ICMP_UGE) {
+
+    BasicBlock *FirstSuccessor = BR->getSuccessor(0);
+    // splitLoop() is expecting LT/LE as exit condition predicate.
+    // Swap operands here if possible to meet this requirement.
+    if (!L->contains(FirstSuccessor)) 
+      CI->swapOperands();
+    else
+      return;
+  }
 
   ExitCondition = CI;