iz80 0.4.4

Z80 and 8080 emulator
Documentation 
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use super::opcode::Opcode;
use super::environment::Environment;
use super::registers::{Flag, Reg16, Reg8};
use super::operators::{Operator, operator_cp};

pub fn build_operator_a_r(r: Reg8, (op, name): (Operator, &str)) -> Opcode {
    if r != Reg8::_HL && r != Reg8::H && r != Reg8::L {
        // Fast version
        Opcode::new(
            format!("{name} A, {r}"),
            move |env: &mut Environment| {
                let a = env.state.reg.a();
                let b = env.state.reg.get8(r);
                let v = op(env, a, b);
                env.state.reg.set_a(v);
            }
        )
    } else {
        Opcode::new(
            format!("{name} A, {r}"),
            move |env: &mut Environment| {
                let a = env.state.reg.a();
                let b = env.reg8_ext(r);
                let v = op(env, a, b);

                env.state.reg.set_a(v);
            }
        )
    }
}

pub fn build_operator_a_n((op, name): (Operator, &str)) -> Opcode {
    Opcode::new(
        format!("{name} A, n"),
        move |env: &mut Environment| {
            let a = env.state.reg.a();
            let b = env.advance_pc();
            let v = op(env, a, b);

            env.state.reg.set_a(v);
        }
    )
}

pub fn build_cp_block((inc, repeat, postfix) : (bool, bool, &'static str)) -> Opcode {
    Opcode::new(
        format!("CP{postfix}"),
        move |env: &mut Environment| {
            let a = env.state.reg.a();
            let b = env.reg8_ext(Reg8::_HL);
            let c_bak = env.state.reg.get_flag(Flag::C);
            operator_cp(env, a, b);
            let bc = env.state.reg.inc_dec16(Reg16::BC, false /*decrement*/);
            env.state.reg.inc_dec16(Reg16::HL, inc);

            // TUZD-4.2
            let mut n = a.wrapping_sub(b);
            if env.state.reg.get_flag(Flag::H) {
                n = n.wrapping_sub(1);
            }
            env.state.reg.update_undocumented_flags_block(n);
            env.state.reg.set_flag(Flag::N);
            env.state.reg.put_flag(Flag::P, bc != 0);
            env.state.reg.put_flag(Flag::C, c_bak); // C unchanged
            // S, Z and H set by operator_cp()

            if repeat && bc != 0 &&  a != b {
                // Back to redo the instruction
                env.set_branch_taken();
                let pc = env.state.reg.pc().wrapping_sub(2);
                env.state.reg.set_pc(pc);
            }
        }
    )
}