yosys/passes/pmgen/peepopt_muldiv.pmg

pattern muldiv

state <SigSpec> t x y
state <bool> is_signed

match mul
	select mul->type == $mul
	select GetSize(port(mul, \A)) + GetSize(port(mul, \B)) <= GetSize(port(mul, \Y))
endmatch

code t x y is_signed
	t = port(mul, \Y);
	x = port(mul, \A);
	y = port(mul, \B);
	is_signed = param(mul, \A_SIGNED).as_bool();
	branch;
	std::swap(x, y);
endcode

match div
	select div->type.in($div)
	index <SigSpec> port(div, \A) === t
	index <SigSpec> port(div, \B) === x
	filter param(div, \A_SIGNED).as_bool() == is_signed
endmatch

code
	SigSpec div_y = port(div, \Y);
	SigSpec val_y = y;

	if (GetSize(div_y) != GetSize(val_y))
		val_y.extend_u0(GetSize(div_y), param(div, \A_SIGNED).as_bool());

	did_something = true;
	log("muldiv pattern in %s: mul=%s, div=%s\n", log_id(module), log_id(mul), log_id(div));
	module->connect(div_y, val_y);
	autoremove(div);
	accept;
endcode