Properly compose subregister indices when coalescing.
The comment about ordering of subreg indices is no longer true.
This exposed a bug in the new substVirtReg method that is also fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105294 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index ce0c5e6..402178d 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -117,7 +117,8 @@
if (SubIdx && getSubReg())
SubIdx = TRI.composeSubRegIndices(SubIdx, getSubReg());
setReg(Reg);
- setSubReg(SubIdx);
+ if (SubIdx)
+ setSubReg(SubIdx);
}
void MachineOperand::substPhysReg(unsigned Reg, const TargetRegisterInfo &TRI) {