Remove SelectionDag early allocation of registers
for earlyclobbers. Teach Local RA about earlyclobber,
and add some tests for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56592 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 0a20128..cd4de34 100644
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -722,6 +722,55 @@
}
}
+ // 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 @@
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 @@
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;