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-rw-r--r--lib/CodeGen/RegisterCoalescer.cpp28
1 files changed, 4 insertions, 24 deletions
diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index dd86c1f010..f0a4b28306 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -816,31 +816,11 @@ bool RegisterCoalescer::reMaterializeTrivialDef(CoalescerPair &CP,
}
if (TargetRegisterInfo::isVirtualRegister(DstReg)) {
+ MRI->setRegClass(DstReg, CP.getNewRC());
+
unsigned NewIdx = NewMI->getOperand(0).getSubReg();
- const TargetRegisterClass *RCForInst;
- if (NewIdx)
- RCForInst = TRI->getMatchingSuperRegClass(MRI->getRegClass(DstReg), DefRC,
- NewIdx);
-
- if (MRI->constrainRegClass(DstReg, DefRC)) {
- // The materialized instruction is quite capable of setting DstReg
- // directly, but it may still have a now-trivial subregister index which
- // we should clear.
- NewMI->getOperand(0).setSubReg(0);
- } else if (NewIdx && RCForInst) {
- // The subreg index on NewMI is essential; we still have to make sure
- // DstReg:idx is in a class that NewMI can use.
- MRI->constrainRegClass(DstReg, RCForInst);
- } else {
- // DstReg is actually incompatible with NewMI, we have to move to a
- // super-reg's class. This could come from a sequence like:
- // GR32 = MOV32r0
- // GR8 = COPY GR32:sub_8
- MRI->setRegClass(DstReg, CP.getNewRC());
- updateRegDefsUses(DstReg, DstReg, DstIdx);
- NewMI->getOperand(0).setSubReg(
- TRI->composeSubRegIndices(SrcIdx, DefMI->getOperand(0).getSubReg()));
- }
+ updateRegDefsUses(DstReg, DstReg, DstIdx);
+ NewMI->getOperand(0).setSubReg(NewIdx);
} else if (NewMI->getOperand(0).getReg() != CopyDstReg) {
// The New instruction may be defining a sub-register of what's actually
// been asked for. If so it must implicitly define the whole thing.