MachineVerifier: Allow physreg use if just a subreg is defined.
We can't mark partially undefined registers, so we have to allow reading
a register in the machine verifier if just parts of a register are
defined.
llvm-svn: 223896
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index 5cdcc66..677b509 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -1066,7 +1066,18 @@
if (!regsLive.count(Reg)) {
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
// Reserved registers may be used even when 'dead'.
- if (!isReserved(Reg))
+ bool Bad = !isReserved(Reg);
+ // We are fine if just any subregister has a defined value.
+ if (Bad) {
+ for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid();
+ ++SubRegs) {
+ if (regsLive.count(*SubRegs)) {
+ Bad = false;
+ break;
+ }
+ }
+ }
+ if (Bad)
report("Using an undefined physical register", MO, MONum);
} else if (MRI->def_empty(Reg)) {
report("Reading virtual register without a def", MO, MONum);