Avoid adding duplicate function live-in's.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104560 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-05-24 21:33:37 +00:00
parent e350690e3b
commit 3946043a80
3 changed files with 21 additions and 2 deletions

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@ -293,6 +293,10 @@ public:
/// corresponding live-in physical register.
unsigned getLiveInPhysReg(unsigned VReg) const;
/// getLiveInVirtReg - If PReg is a live-in physical register, return the
/// corresponding live-in physical register.
unsigned getLiveInVirtReg(unsigned PReg) const;
/// EmitLiveInCopies - Emit copies to initialize livein virtual registers
/// into the given entry block.
void EmitLiveInCopies(MachineBasicBlock *EntryMBB,

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@ -398,8 +398,14 @@ void MachineFunction::viewCFGOnly() const
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;
}

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@ -165,6 +165,15 @@ unsigned MachineRegisterInfo::getLiveInPhysReg(unsigned VReg) const {
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"),