Archipelago » qemu

/*

    NetWinder Floating Point Emulator

    (c) Rebel.COM, 1998,1999

    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>

    This program 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 2 of the License, or

    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "fpa11.h"

#include "fpopcode.h"

unsigned int SingleCPDO(const unsigned int opcode);

unsigned int DoubleCPDO(const unsigned int opcode);

unsigned int ExtendedCPDO(const unsigned int opcode);

unsigned int EmulateCPDO(const unsigned int opcode)

{

   FPA11 *fpa11 = GET_FPA11();

   unsigned int Fd, nType, nDest, nRc = 1;

   //printk("EmulateCPDO(0x%08x)\n",opcode);

   /* Get the destination size.  If not valid let Linux perform

      an invalid instruction trap. */

   nDest = getDestinationSize(opcode);

   if (typeNone == nDest) return 0;

   SetRoundingMode(opcode);

   /* Compare the size of the operands in Fn and Fm.

      Choose the largest size and perform operations in that size,

      in order to make use of all the precision of the operands.

      If Fm is a constant, we just grab a constant of a size

      matching the size of the operand in Fn. */

   if (MONADIC_INSTRUCTION(opcode))

     nType = nDest;

   else

     nType = fpa11->fType[getFn(opcode)];

   if (!CONSTANT_FM(opcode))

   {

     register unsigned int Fm = getFm(opcode);

     if (nType < fpa11->fType[Fm])

     {

        nType = fpa11->fType[Fm];

     }

   }

   switch (nType)

   {

      case typeSingle   : nRc = SingleCPDO(opcode);   break;

      case typeDouble   : nRc = DoubleCPDO(opcode);   break;

      case typeExtended : nRc = ExtendedCPDO(opcode); break;

      default           : nRc = 0;

   }

   /* If the operation succeeded, check to see if the result in the

      destination register is the correct size.  If not force it

      to be. */

   Fd = getFd(opcode);

   nType = fpa11->fType[Fd];

   if ((0 != nRc) && (nDest != nType))

   {

     switch (nDest)

     {

       case typeSingle:

       {

         if (typeDouble == nType)

           fpa11->fpreg[Fd].fSingle =

              float64_to_float32(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status);

         else

           fpa11->fpreg[Fd].fSingle =

              floatx80_to_float32(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status);

       }

       break;

       case typeDouble:

       {

         if (typeSingle == nType)

           fpa11->fpreg[Fd].fDouble =

              float32_to_float64(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status);

         else

           fpa11->fpreg[Fd].fDouble =

              floatx80_to_float64(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status);

       }

       break;

       case typeExtended:

       {

         if (typeSingle == nType)

           fpa11->fpreg[Fd].fExtended =

              float32_to_floatx80(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status);

         else

           fpa11->fpreg[Fd].fExtended =

              float64_to_floatx80(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status);

       }

       break;

     }

     fpa11->fType[Fd] = nDest;

   }

   return nRc;

}