void
MoveEmitterARM::breakCycle(const MoveOperand& from, const MoveOperand& to,
MoveOp::Type type, uint32_t slotId)
{
// There is some pattern:
// (A -> B)
// (B -> A)
//
// This case handles (A -> B), which we reach first. We save B, then allow
// the original move to continue.
switch (type) {
case MoveOp::FLOAT32:
if (to.isMemory()) {
VFPRegister temp = ScratchFloat32Reg;
masm.ma_vldr(toAddress(to), temp);
// Since it is uncertain if the load will be aligned or not
// just fill both of them with the same value.
masm.ma_vstr(temp, cycleSlot(slotId, 0));
masm.ma_vstr(temp, cycleSlot(slotId, 4));
} else if (to.isGeneralReg()) {
// Since it is uncertain if the load will be aligned or not
// just fill both of them with the same value.
masm.ma_str(to.reg(), cycleSlot(slotId, 0));
masm.ma_str(to.reg(), cycleSlot(slotId, 4));
} else {
FloatRegister src = to.floatReg();
// Just always store the largest possible size. Currently, this is
// a double. When SIMD is added, two doubles will need to be stored.
masm.ma_vstr(src.doubleOverlay(), cycleSlot(slotId, 0));
}
break;
case MoveOp::DOUBLE:
if (to.isMemory()) {
ScratchDoubleScope scratch(masm);
masm.ma_vldr(toAddress(to), scratch);
masm.ma_vstr(scratch, cycleSlot(slotId, 0));
} else if (to.isGeneralRegPair()) {
ScratchDoubleScope scratch(masm);
masm.ma_vxfer(to.evenReg(), to.oddReg(), scratch);
masm.ma_vstr(scratch, cycleSlot(slotId, 0));
} else {
masm.ma_vstr(to.floatReg().doubleOverlay(), cycleSlot(slotId, 0));
}
break;
case MoveOp::INT32:
case MoveOp::GENERAL:
// an non-vfp value
if (to.isMemory()) {
Register temp = tempReg();
masm.ma_ldr(toAddress(to), temp);
masm.ma_str(temp, cycleSlot(0,0));
} else {
if (to.reg() == spilledReg_) {
// If the destination was spilled, restore it first.
masm.ma_ldr(spillSlot(), spilledReg_);
spilledReg_ = InvalidReg;
}
masm.ma_str(to.reg(), cycleSlot(0,0));
}
break;
default:
MOZ_CRASH("Unexpected move type");
}
}
