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/>.

// das

void EmulatorPimpl::das2f()

{

    uint16_t flags = registers->get_flags();

    auto al = registers->get(AL);

    auto ah = registers->get(AH);

    if ((al & 0x0f) > 9 || (flags & AF)) {

        uint16_t tmp = al - 6;

        al = tmp & 0xff;

        flags |= AF;

        if (tmp & 0xff00)

            flags |= CF;

    } else {

        flags &= ~AF;

    }

    if (al > 0x9f || (flags & CF)) {

        al -= 0x60;

        flags |= CF;

    } else {

        flags &= ~CF;

    }

    if (al & 0x80)

        flags |= SF;

    if (!al)

        flags |= ZF;

    if (!__builtin_parity(al))

        flags |= PF;

    registers->set(AL, al);

    registers->set(AH, ah);

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

}