qemu

FORK: QEMU emulator
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fpa11_cpdo.c (3431B)

      1 /*
      2     NetWinder Floating Point Emulator
      3     (c) Rebel.COM, 1998,1999
      4 
      5     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
      6 
      7     This program is free software; you can redistribute it and/or modify
      8     it under the terms of the GNU General Public License as published by
      9     the Free Software Foundation; either version 2 of the License, or
     10     (at your option) any later version.
     11 
     12     This program is distributed in the hope that it will be useful,
     13     but WITHOUT ANY WARRANTY; without even the implied warranty of
     14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15     GNU General Public License for more details.
     16 
     17     You should have received a copy of the GNU General Public License
     18     along with this program; if not, see <http://www.gnu.org/licenses/>.
     19 */
     20 
     21 #include "qemu/osdep.h"
     22 #include "fpa11.h"
     23 #include "fpopcode.h"
     24 
     25 unsigned int EmulateCPDO(const unsigned int opcode)
     26 {
     27    FPA11 *fpa11 = GET_FPA11();
     28    unsigned int Fd, nType, nDest, nRc = 1;
     29 
     30    //printk("EmulateCPDO(0x%08x)\n",opcode);
     31 
     32    /* Get the destination size.  If not valid let Linux perform
     33       an invalid instruction trap. */
     34    nDest = getDestinationSize(opcode);
     35    if (typeNone == nDest) return 0;
     36 
     37    SetRoundingMode(opcode);
     38 
     39    /* Compare the size of the operands in Fn and Fm.
     40       Choose the largest size and perform operations in that size,
     41       in order to make use of all the precision of the operands.
     42       If Fm is a constant, we just grab a constant of a size
     43       matching the size of the operand in Fn. */
     44    if (MONADIC_INSTRUCTION(opcode))
     45      nType = nDest;
     46    else
     47      nType = fpa11->fType[getFn(opcode)];
     48 
     49    if (!CONSTANT_FM(opcode))
     50    {
     51      register unsigned int Fm = getFm(opcode);
     52      if (nType < fpa11->fType[Fm])
     53      {
     54         nType = fpa11->fType[Fm];
     55      }
     56    }
     57 
     58    switch (nType)
     59    {
     60       case typeSingle   : nRc = SingleCPDO(opcode);   break;
     61       case typeDouble   : nRc = DoubleCPDO(opcode);   break;
     62       case typeExtended : nRc = ExtendedCPDO(opcode); break;
     63       default           : nRc = 0;
     64    }
     65 
     66    /* If the operation succeeded, check to see if the result in the
     67       destination register is the correct size.  If not force it
     68       to be. */
     69    Fd = getFd(opcode);
     70    nType = fpa11->fType[Fd];
     71    if ((0 != nRc) && (nDest != nType))
     72    {
     73      switch (nDest)
     74      {
     75        case typeSingle:
     76        {
     77          if (typeDouble == nType)
     78            fpa11->fpreg[Fd].fSingle =
     79               float64_to_float32(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status);
     80          else
     81            fpa11->fpreg[Fd].fSingle =
     82               floatx80_to_float32(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status);
     83        }
     84        break;
     85 
     86        case typeDouble:
     87        {
     88          if (typeSingle == nType)
     89            fpa11->fpreg[Fd].fDouble =
     90               float32_to_float64(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status);
     91          else
     92            fpa11->fpreg[Fd].fDouble =
     93               floatx80_to_float64(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status);
     94        }
     95        break;
     96 
     97        case typeExtended:
     98        {
     99          if (typeSingle == nType)
    100            fpa11->fpreg[Fd].fExtended =
    101               float32_to_floatx80(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status);
    102          else
    103            fpa11->fpreg[Fd].fExtended =
    104               float64_to_floatx80(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status);
    105        }
    106        break;
    107      }
    108 
    109      fpa11->fType[Fd] = nDest;
    110    }
    111 
    112    return nRc;
    113 }