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[/] [s80186/] [trunk/] [sim/] [cppmodel/] [instructions/] [imul.cpp] - Blame information for rev 2

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1 2 jamieiles
// Copyright Jamie Iles, 2017
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//
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// This file is part of s80x86.
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//
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// s80x86 is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// s80x86 is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with s80x86.  If not, see <http://www.gnu.org/licenses/>.
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// imul r/m, 8-bit
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void EmulatorPimpl::imulf6()
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{
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    auto old_flags = registers->get_flags();
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    int16_t v1 = sign_extend<int16_t, uint8_t>(read_data<uint8_t>());
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    int16_t v2 = sign_extend<int16_t, uint8_t>(registers->get(AL));
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    uint16_t result, flags;
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    std::tie(flags, result) = do_mul<int16_t>(v1, v2);
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    flags = old_flags & ~(CF | OF | ZF);
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    if (result & 0xff00)
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        flags |= CF | OF;
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    registers->set(AX, result);
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    registers->set_flags(flags, OF | CF | ZF);
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}
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// imul r/m, 16-bit
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void EmulatorPimpl::imulf7()
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{
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    auto old_flags = registers->get_flags();
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    int32_t v1 = sign_extend<int32_t, uint16_t>(read_data<uint16_t>());
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    int32_t v2 = sign_extend<int32_t, uint16_t>(registers->get(AX));
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    uint32_t result;
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    uint16_t flags;
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    std::tie(flags, result) = do_mul<int32_t>(v1, v2);
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    flags = old_flags & ~(CF | OF | ZF);
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    if (result & 0xffff0000)
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        flags |= CF | OF;
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    registers->set(AX, result & 0xffff);
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    registers->set(DX, (result >> 16) & 0xffff);
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    registers->set_flags(flags, OF | CF | ZF);
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}
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// imul r/m, 16-bit immediate
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void EmulatorPimpl::imul69()
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{
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    modrm_decoder->set_width(OP_WIDTH_16);
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    modrm_decoder->decode();
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    auto old_flags = registers->get_flags();
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    int32_t v1 = sign_extend<int32_t, int16_t>(read_data<uint16_t>());
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    int32_t v2 = sign_extend<int32_t, int16_t>(fetch_16bit());
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    uint32_t result;
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    uint16_t flags;
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    std::tie(flags, result) = do_mul<int32_t>(v1, v2);
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    flags = old_flags & ~(CF | OF | ZF);
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    if (result & 0xffff0000)
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        flags |= CF | OF;
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    registers->set(modrm_decoder->reg(), result & 0xffff);
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    registers->set_flags(flags, OF | CF | ZF);
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}
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// imul r/m, 8-bit immediate
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void EmulatorPimpl::imul6b()
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{
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    modrm_decoder->set_width(OP_WIDTH_16);
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    modrm_decoder->decode();
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    auto old_flags = registers->get_flags();
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    int32_t v1 = sign_extend<int32_t, int16_t>(read_data<uint16_t>());
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    int32_t v2 = sign_extend<int32_t, int8_t>(fetch_byte());
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    uint32_t result;
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    uint16_t flags;
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    std::tie(flags, result) = do_mul<int32_t>(v1, v2);
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    flags = old_flags & ~(CF | OF | ZF);
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    if (result & 0xffff0000)
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        flags |= CF | OF;
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    registers->set(modrm_decoder->reg(), result & 0xffff);
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    registers->set_flags(flags, OF | CF | ZF);
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}

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