From 0dba0e5408e999e9c46006a12a92155a961a574c Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 3 Dec 2008 19:32:26 +0000
Subject: [PATCH] When looking for anti-dependences on the critical path, don't
 bother examining non-anti-dependence edges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60496 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/PostRASchedulerList.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index bd9783281cc..73caea96b2e 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -195,6 +195,10 @@ bool SchedulePostRATDList::BreakAntiDependencies() {
     SDep *Edge = CriticalPath[SU->NodeNum];
     SUnit *NextSU = Edge->Dep;
     unsigned AntiDepReg = Edge->Reg;
+    // Only consider anti-dependence edges.
+    if (!Edge->isAntiDep)
+      continue;
+    assert(AntiDepReg != 0 && "Anti-dependence on reg0?");
     // Don't break anti-dependencies on non-allocatable registers.
     if (!AllocatableSet.test(AntiDepReg))
       continue;
-- 
2.34.1