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register-allocated them appropriately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4976 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Misha Brukman 2002-12-12 23:20:31 +00:00
parent 9ada014ec0
commit d1bedcced2
1 changed files with 24 additions and 7 deletions
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31
lib/CodeGen/RegAllocSimple.cpp
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@ -38,6 +38,9 @@ namespace {
// Maps physical register to their register classes
std::map<unsigned, const TargetRegisterClass*> PhysReg2RegClassMap;
// Made to combat the incorrect allocation of r2 = add r1, r1
std::map<unsigned, unsigned> VirtReg2PhysRegMap;
// Maps RegClass => which index we can take a register from. Since this is a
// simple register allocator, when we need a register of a certain class, we
@ -225,17 +228,30 @@ bool RegAllocSimple::runOnMachineFunction(MachineFunction &Fn) {
DEBUG(std::cerr << "const\n");
} else if (op.isVirtualRegister()) {
virtualReg = (unsigned) op.getAllocatedRegNum();
// save register to stack if it's a def
DEBUG(std::cerr << "op: " << op << "\n");
DEBUG(std::cerr << "\t inst[" << i << "]: ";
MI->print(std::cerr, TM));
if (op.opIsDef()) {
physReg = getFreeReg(virtualReg);
MachineBasicBlock::iterator J = I;
J = saveVirtRegToStack(++J, virtualReg, physReg);
I = --J;
// make sure the same virtual register maps to the same physical
// register in any given instruction
if (VirtReg2PhysRegMap.find(virtualReg) != VirtReg2PhysRegMap.end()) {
physReg = VirtReg2PhysRegMap[virtualReg];
} else {
I = moveUseToReg(I, virtualReg, physReg);
if (op.opIsDef()) {
if (TM.getInstrInfo().isTwoAddrInstr(MI->getOpcode()) && i == 0) {
// must be same register number as the first operand
// This maps a = b + c into b += c, and saves b into a's spot
physReg = (unsigned) MI->getOperand(1).getAllocatedRegNum();
} else {
physReg = getFreeReg(virtualReg);
}
MachineBasicBlock::iterator J = I;
J = saveVirtRegToStack(++J, virtualReg, physReg);
I = --J;
} else {
I = moveUseToReg(I, virtualReg, physReg);
}
VirtReg2PhysRegMap[virtualReg] = physReg;
}
MI->SetMachineOperandReg(i, physReg);
DEBUG(std::cerr << "virt: " << virtualReg <<
@ -244,6 +260,7 @@ bool RegAllocSimple::runOnMachineFunction(MachineFunction &Fn) {
}
clearAllRegs();
VirtReg2PhysRegMap.clear();
}
}