Handle cases where a register and one of its super-register are both marked as
defined on the same instruction. This fixes PR1767.
llvm-svn: 43699
diff --git a/llvm/lib/CodeGen/LiveVariables.cpp b/llvm/lib/CodeGen/LiveVariables.cpp
index 57396b7..7e8965e 100644
--- a/llvm/lib/CodeGen/LiveVariables.cpp
+++ b/llvm/lib/CodeGen/LiveVariables.cpp
@@ -203,7 +203,7 @@
RegInfo->isSuperRegister(IncomingReg, Reg) &&
MO.isKill())
// A super-register kill already exists.
- return true;
+ Found = true;
}
}
@@ -357,7 +357,9 @@
} else if (PhysRegPartUse[Reg])
// Add implicit use / kill to last partial use.
addRegisterKilled(Reg, PhysRegPartUse[Reg], true);
- else
+ else if (LastRef != MI)
+ // Defined, but not used. However, watch out for cases where a super-reg
+ // is also defined on the same MI.
addRegisterDead(Reg, LastRef);
}