Avoid adding duplicate function live-in's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104560 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 3cf10b3..a38c881 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -398,8 +398,14 @@
unsigned MachineFunction::addLiveIn(unsigned PReg,
const TargetRegisterClass *RC) {
assert(RC->contains(PReg) && "Not the correct regclass!");
- unsigned VReg = getRegInfo().createVirtualRegister(RC);
- getRegInfo().addLiveIn(PReg, VReg);
+ MachineRegisterInfo &MRI = getRegInfo();
+ unsigned VReg = MRI.getLiveInVirtReg(PReg);
+ if (VReg) {
+ assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
+ return VReg;
+ }
+ VReg = MRI.createVirtualRegister(RC);
+ MRI.addLiveIn(PReg, VReg);
return VReg;
}