Fix PR9962 by properly constraining register classes in RemoveCopyByCommutingDef...

[oota-llvm.git] / lib / CodeGen / SimpleRegisterCoalescing.cpp

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index c33ce24c5e8bb2534fd75a6ae4cf5d31a54d7235..21184895ccbd56033fc8477bc6179168689b56c0 100644 (file)
--- 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);