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Remove SelectionDag early allocation of registers

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for earlyclobbers.  Teach Local RA about earlyclobber,
and add some tests for it.

llvm-svn: 56592
This commit is contained in:
Dale Johannesen
2008-09-24 23:13:09 +00:00
parent 4efed31acf
commit 86d421df23
6 changed files with 96 additions and 43 deletions
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51
llvm/lib/CodeGen/RegAllocLocal.cpp
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@@ -722,6 +722,55 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
}
}
// If any physical regs are earlyclobber, spill any value they might
// have in them, then mark them unallocatable.
// If any virtual regs are earlyclobber, allocate them now (before
// freeing inputs that are killed).
if (MI->getOpcode()==TargetInstrInfo::INLINEASM) {
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
MachineOperand& MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() && MO.isEarlyClobber() &&
MO.getReg()) {
if (TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned DestVirtReg = MO.getReg();
unsigned DestPhysReg;
// If DestVirtReg already has a value, use it.
if (!(DestPhysReg = getVirt2PhysRegMapSlot(DestVirtReg)))
DestPhysReg = getReg(MBB, MI, DestVirtReg);
MF->getRegInfo().setPhysRegUsed(DestPhysReg);
markVirtRegModified(DestVirtReg);
getVirtRegLastUse(DestVirtReg) =
std::make_pair((MachineInstr*)0, 0);
DOUT << " Assigning " << TRI->getName(DestPhysReg)
<< " to %reg" << DestVirtReg << "\n";
MO.setReg(DestPhysReg); // Assign the earlyclobber register
} else {
unsigned Reg = MO.getReg();
if (PhysRegsUsed[Reg] == -2) continue; // Something like ESP.
// These are extra physical register defs when a sub-register
// is defined (def of a sub-register is a read/mod/write of the
// larger registers). Ignore.
if (isReadModWriteImplicitDef(MI, MO.getReg())) continue;
MF->getRegInfo().setPhysRegUsed(Reg);
spillPhysReg(MBB, MI, Reg, true); // Spill any existing value in reg
PhysRegsUsed[Reg] = 0; // It is free and reserved now
AddToPhysRegsUseOrder(Reg);
for (const unsigned *AliasSet = TRI->getSubRegisters(Reg);
*AliasSet; ++AliasSet) {
if (PhysRegsUsed[*AliasSet] != -2) {
MF->getRegInfo().setPhysRegUsed(*AliasSet);
PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now
AddToPhysRegsUseOrder(*AliasSet);
}
}
}
}
}
}
// Get the used operands into registers. This has the potential to spill
// incoming values if we are out of registers. Note that we completely
// ignore physical register uses here. We assume that if an explicit
@@ -778,6 +827,7 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() && !MO.isImplicit() && MO.getReg() &&
!MO.isEarlyClobber() &&
TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
if (PhysRegsUsed[Reg] == -2) continue; // Something like ESP.
@@ -839,6 +889,7 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() && MO.getReg() &&
!MO.isEarlyClobber() &&
TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned DestVirtReg = MO.getReg();
unsigned DestPhysReg;