/* Copyright (C) 2014-2016 Ben Kurtovic <ben.kurtovic@gmail.com>
   Released under the terms of the MIT License. See LICENSE for details. */

/*
    This file contains code to implement the Z80 instruction set. Since there
    are a lot of functions, it is kept separate from the main z80.c file. It is
    included in the middle of z80.c and should not be compiled separately.

    Most of this information can be found in the Z80 User Manual, Revision 06.

    Undocumented opcodes, flags, and some additional details come from:
    - http://clrhome.org/table/
    - http://www.z80.info/z80sflag.htm
*/

/*
    Unimplemented opcode handler.
*/
static uint8_t z80_inst_unimplemented(Z80 *z80, uint8_t opcode)
{
    z80->except = true;
    z80->exc_code = Z80_EXC_UNIMPLEMENTED_OPCODE;
    z80->exc_data = opcode;
    return 4;
}

/*
    LD r, r' (0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x47, 0x48, 0x49, 0x4A, 0x4B,
        0x4C, 0x4D, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x57, 0x58, 0x59,
        0x5A, 0x5B, 0x5C, 0x5D, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x67,
        0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6F, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
        0x7D, 0x7F):
    Load r' (8-bit register) into r (8-bit register).
*/
static uint8_t z80_inst_ld_r_r(Z80 *z80, uint8_t opcode)
{
    uint8_t *dst = extract_reg(z80, opcode),
            *src = extract_reg(z80, opcode << 3);
    *dst = *src;
    z80->regfile.pc++;
    return 4;
}

/*
    LD r, n (0x06, 0x0E, 0x16, 0x1E, 0x26, 0x2E, 0x3E):
    Load n (8-bit immediate) into r (8-bit register).
*/
static uint8_t z80_inst_ld_r_n(Z80 *z80, uint8_t opcode)
{
    uint8_t *reg = extract_reg(z80, opcode);
    *reg = mmu_read_byte(z80->mmu, ++z80->regfile.pc);
    z80->regfile.pc++;
    return 7;
}

/*
    LD r, (HL) (0x46, 0x4E, 0x56, 0x5E, 0x66, 0x6E, 0x7E):
    Load the contents of HL into r (8-bit register).
*/
static uint8_t z80_inst_ld_r_hl(Z80 *z80, uint8_t opcode)
{
    uint8_t *reg = extract_reg(z80, opcode);
    *reg = mmu_read_byte(z80->mmu, get_pair(z80, REG_HL));
    z80->regfile.pc++;
    return 7;
}

/*
    LD r, (IX+d)
*/
// static uint8_t z80_inst_ld_r_ix(Z80 *z80, uint8_t opcode)

/*
    LD r, (IY+d)
*/
// static uint8_t z80_inst_ld_r_iy(Z80 *z80, uint8_t opcode)

/*
    LD (HL), r
*/
// static uint8_t z80_inst_ld_hl_r(Z80 *z80, uint8_t opcode)

/*
    LD (IX+d), r
*/
// static uint8_t z80_inst_ld_ix_r(Z80 *z80, uint8_t opcode)

/*
    LD (IY+d), r
*/
// static uint8_t z80_inst_ld_iy_r(Z80 *z80, uint8_t opcode)

/*
    LD (HL), n
*/
// static uint8_t z80_inst_ld_hl_n(Z80 *z80, uint8_t opcode)

/*
    LD (IX+d), n
*/
// static uint8_t z80_inst_ld_ix_n(Z80 *z80, uint8_t opcode)

/*
    LD (IY+d), n
*/
// static uint8_t z80_inst_ld_iy_n(Z80 *z80, uint8_t opcode)

/*
    LD A, (BC)
*/
// static uint8_t z80_inst_ld_a_bc(Z80 *z80, uint8_t opcode)

/*
    LD A, (DE)
*/
// static uint8_t z80_inst_ld_a_de(Z80 *z80, uint8_t opcode)

/*
    LD A, (nn)
*/
// static uint8_t z80_inst_ld_a_nn(Z80 *z80, uint8_t opcode)

/*
    LD (BC), A
*/
// static uint8_t z80_inst_ld_bc_a(Z80 *z80, uint8_t opcode)

/*
    LD (DE), A
*/
// static uint8_t z80_inst_ld_de_a(Z80 *z80, uint8_t opcode)

/*
    LD (nn), A
*/
// static uint8_t z80_inst_ld_nn_a(Z80 *z80, uint8_t opcode)

/*
    LD A, I
*/
// static uint8_t z80_inst_ld_a_i(Z80 *z80, uint8_t opcode)

/*
    LD A, R
*/
// static uint8_t z80_inst_ld_a_r(Z80 *z80, uint8_t opcode)

/*
    LD I,A
*/
// static uint8_t z80_inst_ld_i_a(Z80 *z80, uint8_t opcode)

/*
    LD R, A
*/
// static uint8_t z80_inst_ld_r_a(Z80 *z80, uint8_t opcode)

/*
    LD dd, nn (0x01, 0x11, 0x21, 0x31):
    Load nn (16-bit immediate) into dd (16-bit register).
*/
static uint8_t z80_inst_ld_dd_nn(Z80 *z80, uint8_t opcode)
{
    uint8_t pair = extract_pair(opcode);
    set_pair(z80, pair, mmu_read_double(z80->mmu, ++z80->regfile.pc));
    z80->regfile.pc += 2;
    return 10;
}

// LD IX, nn

// LD IY, nn

// LD HL, (nn)

// LD dd, (nn)

// LD IX, (nn)

// LD IY, (nn)

// LD (nn), HL

// LD (nn), dd

// LD (nn), IX

// LD (nn), IY

// LD SP, HL

// LD SP, IX

// LD SP, IY

// PUSH qq

// PUSH IX

// PUSH IY

// POP qq

// POP IX

// POP IY

// EX DE, HL

// EX AF, AF′

/*
    EXX (0xD9):
    Exchange the 16-bit registers with their shadows
    (BC <=> BC', DE <=> DE', HL <=> HL').
*/
static uint8_t z80_inst_exx(Z80 *z80, uint8_t opcode)
{
    (void) opcode;
    uint16_t bc = get_pair(z80, REG_BC),
             de = get_pair(z80, REG_DE),
             hl = get_pair(z80, REG_HL);

    set_pair(z80, REG_BC, get_pair(z80, REG_BC_));
    set_pair(z80, REG_DE, get_pair(z80, REG_DE_));
    set_pair(z80, REG_HL, get_pair(z80, REG_HL_));

    set_pair(z80, REG_BC_, bc);
    set_pair(z80, REG_DE_, de);
    set_pair(z80, REG_HL_, hl);
    z80->regfile.pc++;
    return 4;
}

// EX (SP), HL

// EX (SP), IX

// EX (SP), IY

// LDI

// LDIR

// LDD

// LDDR

// CPI

// CPIR

// CPD

// CPDR

// ADD A, r

// ADD A, n

// ADD A, (HL)

// ADD A, (IX + d)

// ADD A, (IY + d)

// ADC A, s

// SUB s

// SBC A, s

// AND s

// OR s

// XOR s

// CP s

/*
    INC r (0x04, 0x0C, 0x14, 0x1C, 0x24, 0x2C, 0x3C):
    Increment r (8-bit register).
*/
static uint8_t z80_inst_inc_r(Z80 *z80, uint8_t opcode)
{
    uint8_t *reg = extract_reg(z80, opcode);
    bool halfcarry = !!(((*reg & 0x0F) + 1) & 0x10);
    (*reg)++;
    update_flags(z80, 0, 0, *reg == 0x80, !!(*reg & 0x08), halfcarry,
                 !!(*reg & 0x20), *reg == 0, !!(*reg & 0x80), 0xFE);

    z80->regfile.pc++;
    return 4;
}

// INC (HL)

// INC (IX+d)

// INC (IY+d)

// DEC m

// DAA

// CPL

// NEG

// CCF

// SCF

/*
    NOP (0x00):
    No operation is performed.
*/
static uint8_t z80_inst_nop(Z80 *z80, uint8_t opcode)
{
    (void) opcode;
    z80->regfile.pc++;
    return 4;
}

/*
    HALT (0x76):
    Suspend CPU operation: execute NOPs until an interrupt or reset.
*/
static uint8_t z80_inst_halt(Z80 *z80, uint8_t opcode)
{
    (void) z80;
    (void) opcode;
    return 4;
}

/*
    DI (0xF3):
    Disable maskable interrupts by resetting both flip-flops.
*/
static uint8_t z80_inst_di(Z80 *z80, uint8_t opcode)
{
    (void) opcode;
    z80->regfile.iff1 = false;
    z80->regfile.iff2 = false;
    z80->regfile.pc++;
    return 4;
}

/*
    EI (0xFB):
    Enable maskable interrupts by setting both flip-flops.
*/
static uint8_t z80_inst_ei(Z80 *z80, uint8_t opcode)
{
    (void) opcode;
    z80->regfile.iff1 = true;
    z80->regfile.iff2 = true;
    z80->regfile.pc++;
    return 4;
}

// IM 0

// IM 1

// IM 2

// ADD HL, ss

// ADC HL, ss

// SBC HL, ss

// ADD IX, pp

// ADD IY, rr

/*
    INC ss (0x03, 0x13, 0x23, 0x33):
    Increment ss (16-bit register).
*/
static uint8_t z80_inst_inc_ss(Z80 *z80, uint8_t opcode)
{
    uint8_t pair = extract_pair(opcode);
    set_pair(z80, pair, get_pair(z80, pair) + 1);
    z80->regfile.pc++;
    return 6;
}

// INC IX

// INC IY

// DEC ss

// DEC IX

// DEC IY

// RLCA

// RLA

// RRCA

// RRA

// RLC r

// RLC (HL)

// RLC (IX+d)

// RLC (IY+d)

// RL m

// RRC m

// RR m

// SLA m

// SRA m

// SRL m

// RLD

// RRD

// BIT b, r

// BIT b, (HL)

// BIT b, (IX+d)

// BIT b, (IY+d)

// SET b, r

// SET b, (HL)

// SET b, (IX+d)

// SET b, (IY+d)

// RES b, m

// JP nn

// JP cc, nn

// JR e

// JR C, e

// JR NC, e

// JR Z, e

// JR NZ, e

// JP (HL)

// JP (IX)

// JP (IY)

// DJNZ, e

// CALL nn

// CALL cc, nn

// RET

// RET cc

// RETI

// RETN

// RST p

// IN A, (n)

// IN r (C)

// INI

// INIR

// IND

// INDR

// OUT (n), A

// OUT (C), r

// OUTI

// OTIR

// OUTD

// OTDR

static uint8_t (*instruction_lookup_table[256])(Z80*, uint8_t) = {
    [0x00] = z80_inst_nop,
    [0x01] = z80_inst_ld_dd_nn,
    [0x02] = z80_inst_unimplemented,  // TODO
    [0x03] = z80_inst_inc_ss,
    [0x04] = z80_inst_inc_r,
    [0x05] = z80_inst_unimplemented,  // TODO
    [0x06] = z80_inst_ld_r_n,
    [0x07] = z80_inst_unimplemented,  // TODO
    [0x08] = z80_inst_unimplemented,  // TODO
    [0x09] = z80_inst_unimplemented,  // TODO
    [0x0A] = z80_inst_unimplemented,  // TODO
    [0x0B] = z80_inst_unimplemented,  // TODO
    [0x0C] = z80_inst_inc_r,
    [0x0D] = z80_inst_unimplemented,  // TODO
    [0x0E] = z80_inst_ld_r_n,
    [0x0F] = z80_inst_unimplemented,  // TODO
    [0x10] = z80_inst_unimplemented,  // TODO
    [0x11] = z80_inst_ld_dd_nn,
    [0x12] = z80_inst_unimplemented,  // TODO
    [0x13] = z80_inst_inc_ss,
    [0x14] = z80_inst_inc_r,
    [0x15] = z80_inst_unimplemented,  // TODO
    [0x16] = z80_inst_ld_r_n,
    [0x17] = z80_inst_unimplemented,  // TODO
    [0x18] = z80_inst_unimplemented,  // TODO
    [0x19] = z80_inst_unimplemented,  // TODO
    [0x1A] = z80_inst_unimplemented,  // TODO
    [0x1B] = z80_inst_unimplemented,  // TODO
    [0x1C] = z80_inst_inc_r,
    [0x1D] = z80_inst_unimplemented,  // TODO
    [0x1E] = z80_inst_ld_r_n,
    [0x1F] = z80_inst_unimplemented,  // TODO
    [0x20] = z80_inst_unimplemented,  // TODO
    [0x21] = z80_inst_ld_dd_nn,
    [0x22] = z80_inst_unimplemented,  // TODO
    [0x23] = z80_inst_inc_ss,
    [0x24] = z80_inst_inc_r,
    [0x25] = z80_inst_unimplemented,  // TODO
    [0x26] = z80_inst_ld_r_n,
    [0x27] = z80_inst_unimplemented,  // TODO
    [0x28] = z80_inst_unimplemented,  // TODO
    [0x29] = z80_inst_unimplemented,  // TODO
    [0x2A] = z80_inst_unimplemented,  // TODO
    [0x2B] = z80_inst_unimplemented,  // TODO
    [0x2C] = z80_inst_inc_r,
    [0x2D] = z80_inst_unimplemented,  // TODO
    [0x2E] = z80_inst_ld_r_n,
    [0x2F] = z80_inst_unimplemented,  // TODO
    [0x30] = z80_inst_unimplemented,  // TODO
    [0x31] = z80_inst_ld_dd_nn,
    [0x32] = z80_inst_unimplemented,  // TODO
    [0x33] = z80_inst_inc_ss,
    [0x34] = z80_inst_unimplemented,  // TODO
    [0x35] = z80_inst_unimplemented,  // TODO
    [0x36] = z80_inst_unimplemented,  // TODO
    [0x37] = z80_inst_unimplemented,  // TODO
    [0x38] = z80_inst_unimplemented,  // TODO
    [0x39] = z80_inst_unimplemented,  // TODO
    [0x3A] = z80_inst_unimplemented,  // TODO
    [0x3B] = z80_inst_unimplemented,  // TODO
    [0x3C] = z80_inst_inc_r,
    [0x3D] = z80_inst_unimplemented,  // TODO
    [0x3E] = z80_inst_ld_r_n,
    [0x3F] = z80_inst_unimplemented,  // TODO
    [0x40] = z80_inst_ld_r_r,
    [0x41] = z80_inst_ld_r_r,
    [0x42] = z80_inst_ld_r_r,
    [0x43] = z80_inst_ld_r_r,
    [0x44] = z80_inst_ld_r_r,
    [0x45] = z80_inst_ld_r_r,
    [0x46] = z80_inst_ld_r_hl,
    [0x47] = z80_inst_ld_r_r,
    [0x48] = z80_inst_ld_r_r,
    [0x49] = z80_inst_ld_r_r,
    [0x4A] = z80_inst_ld_r_r,
    [0x4B] = z80_inst_ld_r_r,
    [0x4C] = z80_inst_ld_r_r,
    [0x4D] = z80_inst_ld_r_r,
    [0x4E] = z80_inst_ld_r_hl,
    [0x4F] = z80_inst_ld_r_r,
    [0x50] = z80_inst_ld_r_r,
    [0x51] = z80_inst_ld_r_r,
    [0x52] = z80_inst_ld_r_r,
    [0x53] = z80_inst_ld_r_r,
    [0x54] = z80_inst_ld_r_r,
    [0x55] = z80_inst_ld_r_r,
    [0x56] = z80_inst_ld_r_hl,
    [0x57] = z80_inst_ld_r_r,
    [0x58] = z80_inst_ld_r_r,
    [0x59] = z80_inst_ld_r_r,
    [0x5A] = z80_inst_ld_r_r,
    [0x5B] = z80_inst_ld_r_r,
    [0x5C] = z80_inst_ld_r_r,
    [0x5D] = z80_inst_ld_r_r,
    [0x5E] = z80_inst_ld_r_hl,
    [0x5F] = z80_inst_ld_r_r,
    [0x60] = z80_inst_ld_r_r,
    [0x61] = z80_inst_ld_r_r,
    [0x62] = z80_inst_ld_r_r,
    [0x63] = z80_inst_ld_r_r,
    [0x64] = z80_inst_ld_r_r,
    [0x65] = z80_inst_ld_r_r,
    [0x66] = z80_inst_ld_r_hl,
    [0x67] = z80_inst_ld_r_r,
    [0x68] = z80_inst_ld_r_r,
    [0x69] = z80_inst_ld_r_r,
    [0x6A] = z80_inst_ld_r_r,
    [0x6B] = z80_inst_ld_r_r,
    [0x6C] = z80_inst_ld_r_r,
    [0x6D] = z80_inst_ld_r_r,
    [0x6E] = z80_inst_ld_r_hl,
    [0x6F] = z80_inst_ld_r_r,
    [0x70] = z80_inst_unimplemented,  // TODO
    [0x71] = z80_inst_unimplemented,  // TODO
    [0x72] = z80_inst_unimplemented,  // TODO
    [0x73] = z80_inst_unimplemented,  // TODO
    [0x74] = z80_inst_unimplemented,  // TODO
    [0x75] = z80_inst_unimplemented,  // TODO
    [0x76] = z80_inst_halt,
    [0x77] = z80_inst_unimplemented,  // TODO
    [0x78] = z80_inst_ld_r_r,
    [0x79] = z80_inst_ld_r_r,
    [0x7A] = z80_inst_ld_r_r,
    [0x7B] = z80_inst_ld_r_r,
    [0x7C] = z80_inst_ld_r_r,
    [0x7D] = z80_inst_ld_r_r,
    [0x7E] = z80_inst_ld_r_hl,
    [0x7F] = z80_inst_ld_r_r,
    [0x80] = z80_inst_unimplemented,  // TODO
    [0x81] = z80_inst_unimplemented,  // TODO
    [0x82] = z80_inst_unimplemented,  // TODO
    [0x83] = z80_inst_unimplemented,  // TODO
    [0x84] = z80_inst_unimplemented,  // TODO
    [0x85] = z80_inst_unimplemented,  // TODO
    [0x86] = z80_inst_unimplemented,  // TODO
    [0x87] = z80_inst_unimplemented,  // TODO
    [0x88] = z80_inst_unimplemented,  // TODO
    [0x89] = z80_inst_unimplemented,  // TODO
    [0x8A] = z80_inst_unimplemented,  // TODO
    [0x8B] = z80_inst_unimplemented,  // TODO
    [0x8C] = z80_inst_unimplemented,  // TODO
    [0x8D] = z80_inst_unimplemented,  // TODO
    [0x8E] = z80_inst_unimplemented,  // TODO
    [0x8F] = z80_inst_unimplemented,  // TODO
    [0x90] = z80_inst_unimplemented,  // TODO
    [0x91] = z80_inst_unimplemented,  // TODO
    [0x92] = z80_inst_unimplemented,  // TODO
    [0x93] = z80_inst_unimplemented,  // TODO
    [0x94] = z80_inst_unimplemented,  // TODO
    [0x95] = z80_inst_unimplemented,  // TODO
    [0x96] = z80_inst_unimplemented,  // TODO
    [0x97] = z80_inst_unimplemented,  // TODO
    [0x98] = z80_inst_unimplemented,  // TODO
    [0x99] = z80_inst_unimplemented,  // TODO
    [0x9A] = z80_inst_unimplemented,  // TODO
    [0x9B] = z80_inst_unimplemented,  // TODO
    [0x9C] = z80_inst_unimplemented,  // TODO
    [0x9D] = z80_inst_unimplemented,  // TODO
    [0x9E] = z80_inst_unimplemented,  // TODO
    [0x9F] = z80_inst_unimplemented,  // TODO
    [0xA0] = z80_inst_unimplemented,  // TODO
    [0xA1] = z80_inst_unimplemented,  // TODO
    [0xA2] = z80_inst_unimplemented,  // TODO
    [0xA3] = z80_inst_unimplemented,  // TODO
    [0xA4] = z80_inst_unimplemented,  // TODO
    [0xA5] = z80_inst_unimplemented,  // TODO
    [0xA6] = z80_inst_unimplemented,  // TODO
    [0xA7] = z80_inst_unimplemented,  // TODO
    [0xA8] = z80_inst_unimplemented,  // TODO
    [0xA9] = z80_inst_unimplemented,  // TODO
    [0xAA] = z80_inst_unimplemented,  // TODO
    [0xAB] = z80_inst_unimplemented,  // TODO
    [0xAC] = z80_inst_unimplemented,  // TODO
    [0xAD] = z80_inst_unimplemented,  // TODO
    [0xAE] = z80_inst_unimplemented,  // TODO
    [0xAF] = z80_inst_unimplemented,  // TODO
    [0xB0] = z80_inst_unimplemented,  // TODO
    [0xB1] = z80_inst_unimplemented,  // TODO
    [0xB2] = z80_inst_unimplemented,  // TODO
    [0xB3] = z80_inst_unimplemented,  // TODO
    [0xB4] = z80_inst_unimplemented,  // TODO
    [0xB5] = z80_inst_unimplemented,  // TODO
    [0xB6] = z80_inst_unimplemented,  // TODO
    [0xB7] = z80_inst_unimplemented,  // TODO
    [0xB8] = z80_inst_unimplemented,  // TODO
    [0xB9] = z80_inst_unimplemented,  // TODO
    [0xBA] = z80_inst_unimplemented,  // TODO
    [0xBB] = z80_inst_unimplemented,  // TODO
    [0xBC] = z80_inst_unimplemented,  // TODO
    [0xBD] = z80_inst_unimplemented,  // TODO
    [0xBE] = z80_inst_unimplemented,  // TODO
    [0xBF] = z80_inst_unimplemented,  // TODO
    [0xC0] = z80_inst_unimplemented,  // TODO
    [0xC1] = z80_inst_unimplemented,  // TODO
    [0xC2] = z80_inst_unimplemented,  // TODO
    [0xC3] = z80_inst_unimplemented,  // TODO
    [0xC4] = z80_inst_unimplemented,  // TODO
    [0xC5] = z80_inst_unimplemented,  // TODO
    [0xC6] = z80_inst_unimplemented,  // TODO
    [0xC7] = z80_inst_unimplemented,  // TODO
    [0xC8] = z80_inst_unimplemented,  // TODO
    [0xC9] = z80_inst_unimplemented,  // TODO
    [0xCA] = z80_inst_unimplemented,  // TODO
    [0xCB] = z80_inst_unimplemented,  // TODO
    [0xCC] = z80_inst_unimplemented,  // TODO
    [0xCD] = z80_inst_unimplemented,  // TODO
    [0xCE] = z80_inst_unimplemented,  // TODO
    [0xCF] = z80_inst_unimplemented,  // TODO
    [0xD0] = z80_inst_unimplemented,  // TODO
    [0xD1] = z80_inst_unimplemented,  // TODO
    [0xD2] = z80_inst_unimplemented,  // TODO
    [0xD3] = z80_inst_unimplemented,  // TODO
    [0xD4] = z80_inst_unimplemented,  // TODO
    [0xD5] = z80_inst_unimplemented,  // TODO
    [0xD6] = z80_inst_unimplemented,  // TODO
    [0xD7] = z80_inst_unimplemented,  // TODO
    [0xD8] = z80_inst_unimplemented,  // TODO
    [0xD9] = z80_inst_exx,
    [0xDA] = z80_inst_unimplemented,  // TODO
    [0xDB] = z80_inst_unimplemented,  // TODO
    [0xDC] = z80_inst_unimplemented,  // TODO
    [0xDD] = z80_inst_unimplemented,  // TODO
    [0xDE] = z80_inst_unimplemented,  // TODO
    [0xDF] = z80_inst_unimplemented,  // TODO
    [0xE0] = z80_inst_unimplemented,  // TODO
    [0xE1] = z80_inst_unimplemented,  // TODO
    [0xE2] = z80_inst_unimplemented,  // TODO
    [0xE3] = z80_inst_unimplemented,  // TODO
    [0xE4] = z80_inst_unimplemented,  // TODO
    [0xE5] = z80_inst_unimplemented,  // TODO
    [0xE6] = z80_inst_unimplemented,  // TODO
    [0xE7] = z80_inst_unimplemented,  // TODO
    [0xE8] = z80_inst_unimplemented,  // TODO
    [0xE9] = z80_inst_unimplemented,  // TODO
    [0xEA] = z80_inst_unimplemented,  // TODO
    [0xEB] = z80_inst_unimplemented,  // TODO
    [0xEC] = z80_inst_unimplemented,  // TODO
    [0xED] = z80_inst_unimplemented,  // TODO
    [0xEE] = z80_inst_unimplemented,  // TODO
    [0xEF] = z80_inst_unimplemented,  // TODO
    [0xF0] = z80_inst_unimplemented,  // TODO
    [0xF1] = z80_inst_unimplemented,  // TODO
    [0xF2] = z80_inst_unimplemented,  // TODO
    [0xF3] = z80_inst_di,
    [0xF4] = z80_inst_unimplemented,  // TODO
    [0xF5] = z80_inst_unimplemented,  // TODO
    [0xF6] = z80_inst_unimplemented,  // TODO
    [0xF7] = z80_inst_unimplemented,  // TODO
    [0xF8] = z80_inst_unimplemented,  // TODO
    [0xF9] = z80_inst_unimplemented,  // TODO
    [0xFA] = z80_inst_unimplemented,  // TODO
    [0xFB] = z80_inst_ei,
    [0xFC] = z80_inst_unimplemented,  // TODO
    [0xFD] = z80_inst_unimplemented,  // TODO
    [0xFE] = z80_inst_unimplemented,  // TODO
    [0xFF] = z80_inst_unimplemented   // TODO
};