Nuke noop copies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24258 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-11-09 18:22:42 +00:00
parent 6b2d69655a
commit e6a88ac1b9

View File

@ -488,9 +488,11 @@ MachineInstr *RA::reloadVirtReg(MachineBasicBlock &MBB, MachineInstr *MI,
void RA::AllocateBasicBlock(MachineBasicBlock &MBB) {
// loop over each instruction
MachineBasicBlock::iterator MI = MBB.begin();
for (; MI != MBB.end(); ++MI) {
const TargetInstrDescriptor &TID = TM->getInstrInfo()->get(MI->getOpcode());
MachineBasicBlock::iterator MII = MBB.begin();
const TargetInstrInfo &TII = *TM->getInstrInfo();
while (MII != MBB.end()) {
MachineInstr *MI = MII++;
const TargetInstrDescriptor &TID = TII.get(MI->getOpcode());
DEBUG(std::cerr << "\nStarting RegAlloc of: " << *MI;
std::cerr << " Regs have values: ";
for (unsigned i = 0; i != RegInfo->getNumRegs(); ++i)
@ -621,9 +623,14 @@ void RA::AllocateBasicBlock(MachineBasicBlock &MBB) {
removePhysReg(PhysReg);
}
}
// Finally, if this is a noop copy instruction, zap it.
unsigned SrcReg, DstReg;
if (TII.isMoveInstr(*MI, SrcReg, DstReg) && SrcReg == DstReg)
MBB.erase(MI);
}
MI = MBB.getFirstTerminator();
MachineBasicBlock::iterator MI = MBB.getFirstTerminator();
// Spill all physical registers holding virtual registers now.
for (unsigned i = 0, e = RegInfo->getNumRegs(); i != e; ++i)