Mips: Don't create copy of nothing

This was creating a copy of the register the pseudo itself was
def'ing, leaving a copy of an undefined register. I'm not sure how
the verifier is not catching this, but this avoids asserting in a
future change to RegAllocFast

llvm-svn: 356716

1 files changed, 0 insertions, 2 deletions

diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index 95c0103bbc8..21c7cf2dd79 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -1750,12 +1750,10 @@ MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
   // after fast register allocation, the spills will end up outside of the
   // blocks that their values are defined in, causing livein errors.
 
-  unsigned DestCopy = MRI.createVirtualRegister(MRI.getRegClass(Dest));
   unsigned PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
   unsigned OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
   unsigned NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
 
-  BuildMI(*BB, II, DL, TII->get(Mips::COPY), DestCopy).addReg(Dest);
   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);