def _InsRewriteDivRemShifts(ins: ir.Ins,
fun: ir.Fun) -> Optional[List[ir.Ins]]:
opc = ins.opcode
ops = ins.operands
if opc is o.DIV and ops[0].kind.flavor() != o.DK_FLAVOR_F:
# note: we could leave it to the register allocator to pick a CpuReg for ops[2]
# but then we would somehow have to ensure that the reg is NOT rdx.
# By forcing rcx for ops[2] we sidestep the issue
rax = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rax"], ops[0].kind)
rcx = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rcx"], ops[0].kind)
rdx = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rdx"], ops[0].kind)
return [
ir.Ins(o.MOV, [rax, ops[1]]),
ir.Ins(o.MOV, [rcx, ops[2]]),
ir.Ins(o.DIV, [rdx, rax, rcx
]), # note the notion of src/dst regs is murky here
ir.Ins(o.MOV, [ops[0], rax])
]
elif opc is o.REM and ops[0].kind.flavor() != o.DK_FLAVOR_F:
rax = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rax"], ops[0].kind)
rcx = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rcx"], ops[0].kind)
rdx = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rdx"], ops[0].kind)
return [
ir.Ins(o.MOV, [rax, ops[1]]),
ir.Ins(o.MOV, [rcx, ops[2]]),
ir.Ins(o.DIV, [rdx, rax, rcx
]), # note the notion of src/dst regs is murky here
ir.Ins(o.MOV, [ops[0], rdx])
]
elif opc in {o.SHR, o.SHL} and isinstance(ops[2], ir.Reg):
rcx = fun.FindOrAddCpuReg(regs.CPU_REGS_MAP["rcx"], ops[0].kind)
mov = ir.Ins(o.MOV, [rcx, ops[2]])
ops[2] = rcx
mask = _SHIFT_MASK.get(ops[0].kind)
if mask:
return [mov, ir.Ins(o.AND, [rcx, rcx, mask]), ins]
else:
return [mov, ins]
else:
return None
def _InsPushargConversionReverse(ins: ir.Ins, fun: ir.Fun,
params: List[ir.CpuReg]) -> Optional[
List[ir.Ins]]:
"""
This pass converts pusharg reg -> mov arg_reg = reg
Note:
* params is passed around between calls to this function
* pusharg's always precede calls or returns
"""
if ins.opcode is o.PUSHARG:
cpu_reg = params.pop(0)
src = ins.operands[0]
reg = fun.FindOrAddCpuReg(cpu_reg, src.kind)
return [ir.Ins(o.MOV, [reg, src])]
assert not params, f"params {params} should be empty at ins {ins} {ins.operands}"
if ins.opcode.is_call():
callee: ir.Fun = cfg.InsCallee(ins)
assert isinstance(callee, ir.Fun)
params += GetCpuRegsForSignature(callee.input_types)
elif ins.opcode is o.RET:
params += GetCpuRegsForSignature(fun.output_types)
return None
def _InsPopargConversion(ins: ir.Ins, fun: ir.Fun,
params: List[ir.CpuReg]) -> Optional[List[ir.Ins]]:
"""
This pass converts `poparg reg` -> `mov reg = arg_reg`
it must used in a forward pass over the Bbl and will update `param`
for use with the next Ins in the BBl. The initial value of `param`
reflects the Fun's arguments.
"""
if ins.opcode is o.POPARG:
cpu_reg = params.pop(0)
dst = ins.operands[0]
# assert dst.kind == cpu_reg.kind
reg = fun.FindOrAddCpuReg(cpu_reg, dst.kind)
return [ir.Ins(o.MOV, [dst, reg])]
assert not params, f"params {params} should be empty at ins {ins}"
if ins.opcode.is_call():
callee: ir.Fun = cfg.InsCallee(ins)
assert isinstance(callee, ir.Fun)
params += GetCpuRegsForSignature(callee.output_types)
return None