Subversion Repositories s80186

// Copyright Jamie Iles, 2017

//

// This file is part of s80x86.

//

// s80x86 is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// s80x86 is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with s80x86.  If not, see <http://www.gnu.org/licenses/>.

// inc r/m, 8-bit

void EmulatorPimpl::inc_dec_fe()

{

    modrm_decoder->set_width(OP_WIDTH_8);

    modrm_decoder->decode();

    if (modrm_decoder->raw_reg() == 7) {

        invalid_opcode();

        return;

    }

    if (modrm_decoder->raw_reg() != 0 && modrm_decoder->raw_reg() != 1) {

        std::cerr << "warning: invalid reg " << std::hex

                  << (unsigned)modrm_decoder->raw_reg() << " for opcode 0x"

                  << opcode << std::endl;

        return;

    }

    uint8_t v = read_data<uint8_t>();

    uint8_t result;

    uint16_t flags;

    if (modrm_decoder->raw_reg() == 0)

        std::tie(flags, result) = do_add<uint8_t>(v, 1);

    else

        std::tie(flags, result) = do_sub<uint8_t>(v, 1);

    registers->set_flags(flags, OF | SF | ZF | AF | PF);

    write_data<uint8_t>(result);

}

// inc r/m, 16-bit

void EmulatorPimpl::incff()

{

    assert(modrm_decoder->raw_reg() == 0);

    uint16_t v = read_data<uint16_t>();

    uint16_t result;

    uint16_t flags;

    std::tie(flags, result) = do_add<uint16_t>(v, 1);

    registers->set_flags(flags, OF | SF | ZF | AF | PF);

    write_data<uint16_t>(result);

}

// inc r, 16-bit

void EmulatorPimpl::inc40_47()

{

    auto reg = static_cast<GPR>(static_cast<int>(AX) + (opcode & 0x7));

    auto v = registers->get(reg);

    uint16_t result;

    uint16_t flags;

    std::tie(flags, result) = do_add<uint16_t>(v, 1);

    registers->set_flags(flags, OF | SF | ZF | AF | PF);

    registers->set(reg, result);

}

// dec r/m, 16-bit

void EmulatorPimpl::decff()

{

    assert(modrm_decoder->raw_reg() == 1);

    uint16_t v = read_data<uint16_t>();

    uint16_t result;

    uint16_t flags;

    std::tie(flags, result) = do_sub<uint16_t>(v, 1);

    registers->set_flags(flags, OF | SF | ZF | AF | PF);

    write_data<uint16_t>(result);

}

// dec r, 16-bit

void EmulatorPimpl::dec48_4f()

{

    auto reg = static_cast<GPR>(static_cast<int>(AX) + (opcode & 0x7));

    auto v = registers->get(reg);

    uint16_t result;

    uint16_t flags;

    std::tie(flags, result) = do_sub<uint16_t>(v, 1);

    registers->set_flags(flags, OF | SF | ZF | AF | PF);

    registers->set(reg, result);

}