// Not a copy.
SmallVector<unsigned, 2> Defs;
- bool HasRegMask = false;
+ int RegMaskOpNum = -1;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegMask())
- HasRegMask = true;
+ RegMaskOpNum = i;
if (!MO.isReg())
continue;
unsigned Reg = MO.getReg();
// a large set of registers. It is possible to use the register mask to
// prune the available copies, but treat it like a basic block boundary for
// now.
- if (HasRegMask) {
- // FIXME: We could possibly erase some MaybeDeadCopies if their registers
- // are clobbered by the mask.
+ if (RegMaskOpNum >= 0) {
+ // Erase any MaybeDeadCopies whose destination register is clobbered.
+ const MachineOperand &MaskMO = MI->getOperand(RegMaskOpNum);
+ for (SmallSetVector<MachineInstr*, 8>::iterator
+ DI = MaybeDeadCopies.begin(), DE = MaybeDeadCopies.end();
+ DI != DE; ++DI) {
+ unsigned Reg = (*DI)->getOperand(0).getReg();
+ if (ReservedRegs.test(Reg) || !MaskMO.clobbersPhysReg(Reg))
+ continue;
+ (*DI)->eraseFromParent();
+ Changed = true;
+ ++NumDeletes;
+ }
+
+ // Clear all data structures as if we were beginning a new basic block.
MaybeDeadCopies.clear();
AvailCopyMap.clear();
CopyMap.clear();