void
MoveEmitterARM::emitDoubleMove(const MoveOperand& from, const MoveOperand& to)
{
// Registers are used to store pointers / int32 / float32 values.
MOZ_ASSERT(!from.isGeneralReg());
MOZ_ASSERT(!to.isGeneralReg());
if (from.isFloatReg()) {
if (to.isFloatReg())
masm.ma_vmov(from.floatReg(), to.floatReg());
else if (to.isGeneralRegPair())
masm.ma_vxfer(from.floatReg(), to.evenReg(), to.oddReg());
else
masm.ma_vstr(from.floatReg(), toAddress(to));
} else if (from.isGeneralRegPair()) {
if (to.isFloatReg())
masm.ma_vxfer(from.evenReg(), from.oddReg(), to.floatReg());
else if (to.isGeneralRegPair()) {
MOZ_ASSERT(!from.aliases(to));
masm.ma_mov(from.evenReg(), to.evenReg());
masm.ma_mov(from.oddReg(), to.oddReg());
} else {
FloatRegister reg = ScratchDoubleReg;
masm.ma_vxfer(from.evenReg(), from.oddReg(), reg);
masm.ma_vstr(reg, toAddress(to));
}
} else if (to.isFloatReg()) {
masm.ma_vldr(toAddress(from), to.floatReg());
} else if (to.isGeneralRegPair()) {
MOZ_ASSERT(from.isMemory());
Address src = toAddress(from);
// Note: We can safely use the MoveOperand's displacement here,
// even if the base is SP: MoveEmitter::toOperand adjusts
// SP-relative operands by the difference between the current
// stack usage and stackAdjust, which emitter.finish() resets to
// 0.
//
// Warning: if the offset isn't within [-255,+255] then this
// will assert-fail (or, if non-debug, load the wrong words).
// Nothing uses such an offset at the time of this writing.
masm.ma_ldrd(EDtrAddr(src.base, EDtrOffImm(src.offset)), to.evenReg(), to.oddReg());
} else {
// Memory to memory move.
MOZ_ASSERT(from.isMemory());
ScratchDoubleScope scratch(masm);
masm.ma_vldr(toAddress(from), scratch);
masm.ma_vstr(scratch, toAddress(to));
}
}
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");
}
}
void
MoveEmitterARM::completeCycle(const MoveOperand& from, const MoveOperand& to, MoveOp::Type type, uint32_t slotId)
{
// There is some pattern:
// (A -> B)
// (B -> A)
//
// This case handles (B -> A), which we reach last. We emit a move from the
// saved value of B, to A.
switch (type) {
case MoveOp::FLOAT32:
MOZ_ASSERT(!to.isGeneralRegPair());
if (to.isMemory()) {
ScratchFloat32Scope scratch(masm);
masm.ma_vldr(cycleSlot(slotId, 0), scratch);
masm.ma_vstr(scratch, toAddress(to));
} else if (to.isGeneralReg()) {
MOZ_ASSERT(type == MoveOp::FLOAT32);
masm.ma_ldr(toAddress(from), to.reg());
} else {
uint32_t offset = 0;
if ((!from.isMemory()) && from.floatReg().numAlignedAliased() == 1)
offset = sizeof(float);
masm.ma_vldr(cycleSlot(slotId, offset), to.floatReg());
}
break;
case MoveOp::DOUBLE:
MOZ_ASSERT(!to.isGeneralReg());
if (to.isMemory()) {
ScratchDoubleScope scratch(masm);
masm.ma_vldr(cycleSlot(slotId, 0), scratch);
masm.ma_vstr(scratch, toAddress(to));
} else if (to.isGeneralRegPair()) {
MOZ_ASSERT(type == MoveOp::DOUBLE);
ScratchDoubleScope scratch(masm);
masm.ma_vldr(toAddress(from), scratch);
masm.ma_vxfer(scratch, to.evenReg(), to.oddReg());
} else {
uint32_t offset = 0;
if ((!from.isMemory()) && from.floatReg().numAlignedAliased() == 1)
offset = sizeof(float);
masm.ma_vldr(cycleSlot(slotId, offset), to.floatReg());
}
break;
case MoveOp::INT32:
case MoveOp::GENERAL:
MOZ_ASSERT(slotId == 0);
if (to.isMemory()) {
Register temp = tempReg();
masm.ma_ldr(cycleSlot(slotId, 0), temp);
masm.ma_str(temp, toAddress(to));
} else {
if (to.reg() == spilledReg_) {
// Make sure we don't re-clobber the spilled register later.
spilledReg_ = InvalidReg;
}
masm.ma_ldr(cycleSlot(slotId, 0), to.reg());
}
break;
default:
MOZ_CRASH("Unexpected move type");
}
}