REG_SEQUENCE expansion to COPY instructions wasn't taking account of sub register indices on the source registers. No simple test case

llvm-svn: 154051

Author: cooperp

llvm/lib/CodeGen/TwoAddressInstructionPass.cpp

@@ -1832,6 +1832,7 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
     SmallSet<unsigned, 4> Seen;
     for (unsigned i = 1, e = MI->getNumOperands(); i < e; i += 2) {
       unsigned SrcReg = MI->getOperand(i).getReg();
+      unsigned SrcSubIdx = MI->getOperand(i).getSubReg();
       unsigned SubIdx = MI->getOperand(i+1).getImm();
       // DefMI of NULL means the value does not have a vreg in this block
       // i.e., its a physical register or a subreg.
@@ -1887,7 +1888,7 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
         MachineInstr *CopyMI = BuildMI(*MI->getParent(), InsertLoc,
                                 MI->getDebugLoc(), TII->get(TargetOpcode::COPY))
             .addReg(DstReg, RegState::Define, SubIdx)
-            .addReg(SrcReg, getKillRegState(isKill));
+            .addReg(SrcReg, getKillRegState(isKill), SrcSubIdx);
         MI->getOperand(i).setReg(0);
         if (LV && isKill && !TargetRegisterInfo::isPhysicalRegister(SrcReg))
           LV->replaceKillInstruction(SrcReg, MI, CopyMI);