Fix crash in machine verifier when trying to print the def of a register which has no def
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160531 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index fca051e..d8dece6 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -837,6 +837,8 @@
// Reserved registers may be used even when 'dead'.
if (!isReserved(Reg))
report("Using an undefined physical register", MO, MONum);
+ } else if (MRI->def_empty(Reg)) {
+ report("Reading virtual register without a def", MO, MONum);
} else {
BBInfo &MInfo = MBBInfoMap[MI->getParent()];
// We don't know which virtual registers are live in, so only complain