arch/arm/nwfpe/fpa11_cpdo.c

   1 /*
   2     NetWinder Floating Point Emulator
   3     (c) Rebel.COM, 1998,1999
   4     (c) Philip Blundell, 2001
   5
   6     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include <linux/config.h>
  24 #include "fpa11.h"
  25 #include "fpopcode.h"
  26
  27 unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
  28 unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
  29 unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
  30
  31 unsigned int EmulateCPDO(const unsigned int opcode)
  32 {
  33         FPA11 *fpa11 = GET_FPA11();
  34         FPREG *rFd;
  35         unsigned int nType, nDest, nRc;
  36         struct roundingData roundData;
  37
  38         /* Get the destination size.  If not valid let Linux perform
  39            an invalid instruction trap. */
  40         nDest = getDestinationSize(opcode);
  41         if (typeNone == nDest)
  42                 return 0;
  43
  44         roundData.mode = SetRoundingMode(opcode);
  45         roundData.precision = SetRoundingPrecision(opcode);
  46         roundData.exception = 0;
  47
  48         /* Compare the size of the operands in Fn and Fm.
  49            Choose the largest size and perform operations in that size,
  50            in order to make use of all the precision of the operands.
  51            If Fm is a constant, we just grab a constant of a size
  52            matching the size of the operand in Fn. */
  53         if (MONADIC_INSTRUCTION(opcode))
  54                 nType = nDest;
  55         else
  56                 nType = fpa11->fType[getFn(opcode)];
  57
  58         if (!CONSTANT_FM(opcode)) {
  59                 register unsigned int Fm = getFm(opcode);
  60                 if (nType < fpa11->fType[Fm]) {
  61                         nType = fpa11->fType[Fm];
  62                 }
  63         }
  64
  65         rFd = &fpa11->fpreg[getFd(opcode)];
  66
  67         switch (nType) {
  68         case typeSingle:
  69                 nRc = SingleCPDO(&roundData, opcode, rFd);
  70                 break;
  71         case typeDouble:
  72                 nRc = DoubleCPDO(&roundData, opcode, rFd);
  73                 break;
  74 #ifdef CONFIG_FPE_NWFPE_XP
  75         case typeExtended:
  76                 nRc = ExtendedCPDO(&roundData, opcode, rFd);
  77                 break;
  78 #endif
  79         default:
  80                 nRc = 0;
  81         }
  82
  83         /* The CPDO functions used to always set the destination type
  84            to be the same as their working size. */
  85
  86         if (nRc != 0) {
  87                 /* If the operation succeeded, check to see if the result in the
  88                    destination register is the correct size.  If not force it
  89                    to be. */
  90
  91                 fpa11->fType[getFd(opcode)] = nDest;
  92
  93 #ifdef CONFIG_FPE_NWFPE_XP
  94                 if (nDest != nType) {
  95                         switch (nDest) {
  96                         case typeSingle:
  97                                 {
  98                                         if (typeDouble == nType)
  99                                                 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
 100                                         else
 101                                                 rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
 102                                 }
 103                                 break;
 104
 105                         case typeDouble:
 106                                 {
 107                                         if (typeSingle == nType)
 108                                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 109                                         else
 110                                                 rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
 111                                 }
 112                                 break;
 113
 114                         case typeExtended:
 115                                 {
 116                                         if (typeSingle == nType)
 117                                                 rFd->fExtended = float32_to_floatx80(rFd->fSingle);
 118                                         else
 119                                                 rFd->fExtended = float64_to_floatx80(rFd->fDouble);
 120                                 }
 121                                 break;
 122                         }
 123                 }
 124 #else
 125                 if (nDest != nType) {
 126                         if (nDest == typeSingle)
 127                                 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
 128                         else
 129                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 130                 }
 131 #endif
 132         }
 133
 134         if (roundData.exception)
 135                 float_raise(roundData.exception);
 136
 137         return nRc;
 138 }