Handle <undef> flag in machine code verifier.
Use of an <undef> register is treated like an <imp-use>. It is not an error to use a dead <undef> register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77890 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index a13d39e..59864fb 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -365,7 +365,8 @@
addRegWithSubRegs(regsKilled, Reg);
}
// Explicit use of a dead register.
- if (!MO->isImplicit() && !regsLive.count(Reg)) {
+ // A register use marked <undef> is OK.
+ if (!MO->isImplicit() && !MO->isUndef() && !regsLive.count(Reg)) {
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
// Reserved registers may be used even when 'dead'.
if (!isReserved(Reg))