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;
}
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 402be47..70bf7e5 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -165,6 +165,15 @@
return 0;
}
+/// getLiveInVirtReg - If PReg is a live-in physical register, return the
+/// corresponding live-in physical register.
+unsigned MachineRegisterInfo::getLiveInVirtReg(unsigned PReg) const {
+ for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
+ if (I->first == PReg)
+ return I->second;
+ return 0;
+}
+
static cl::opt<bool>
SchedLiveInCopies("schedule-livein-copies", cl::Hidden,
cl::desc("Schedule copies of livein registers"),