From 345968c82d73d7b770a377d91ecea53c4672d48b Mon Sep 17 00:00:00 2001
From: Cameron Zwarich <zwarich@apple.com>
Date: Fri, 20 May 2011 23:25:36 +0000
Subject: [PATCH] Fix PR9962 by properly constraining register classes in
 RemoveCopyByCommutingDef(). This actually fixes most of the VerifyCoalescing
 failures in test-suite.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131768 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SimpleRegisterCoalescing.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index c33ce24c5e8..21184895ccb 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -430,6 +430,10 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(const CoalescerPair &CP,
   MachineInstr *NewMI = tii_->commuteInstruction(DefMI);
   if (!NewMI)
     return false;
+  if (TargetRegisterInfo::isVirtualRegister(IntA.reg) &&
+      TargetRegisterInfo::isVirtualRegister(IntB.reg) &&
+      !mri_->constrainRegClass(IntB.reg, mri_->getRegClass(IntA.reg)))
+    return false;
   if (NewMI != DefMI) {
     li_->ReplaceMachineInstrInMaps(DefMI, NewMI);
     MBB->insert(DefMI, NewMI);
-- 
2.34.1