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 "fpa11.h"
  24 #include "fpopcode.h"
  25
  26 unsigned int SingleCPDO(const unsigned int opcode, FPREG * rFd);
  27 unsigned int DoubleCPDO(const unsigned int opcode, FPREG * rFd);
  28 unsigned int ExtendedCPDO(const unsigned int opcode, FPREG * rFd);
  29
  30 unsigned int EmulateCPDO(const unsigned int opcode)
  31 {
  32         FPA11 *fpa11 = GET_FPA11();
  33         FPREG *rFd;
  34         unsigned int nType, nDest, nRc;
  35
  36         /* Get the destination size.  If not valid let Linux perform
  37            an invalid instruction trap. */
  38         nDest = getDestinationSize(opcode);
  39         if (typeNone == nDest)
  40                 return 0;
  41
  42         SetRoundingMode(opcode);
  43
  44         /* Compare the size of the operands in Fn and Fm.
  45            Choose the largest size and perform operations in that size,
  46            in order to make use of all the precision of the operands.
  47            If Fm is a constant, we just grab a constant of a size
  48            matching the size of the operand in Fn. */
  49         if (MONADIC_INSTRUCTION(opcode))
  50                 nType = nDest;
  51         else
  52                 nType = fpa11->fType[getFn(opcode)];
  53
  54         if (!CONSTANT_FM(opcode)) {
  55                 register unsigned int Fm = getFm(opcode);
  56                 if (nType < fpa11->fType[Fm]) {
  57                         nType = fpa11->fType[Fm];
  58                 }
  59         }
  60
  61         rFd = &fpa11->fpreg[getFd(opcode)];
  62
  63         switch (nType) {
  64         case typeSingle:
  65                 nRc = SingleCPDO(opcode, rFd);
  66                 break;
  67         case typeDouble:
  68                 nRc = DoubleCPDO(opcode, rFd);
  69                 break;
  70 #ifdef CONFIG_FPE_NWFPE_XP
  71         case typeExtended:
  72                 nRc = ExtendedCPDO(opcode, rFd);
  73                 break;
  74 #endif
  75         default:
  76                 nRc = 0;
  77         }
  78
  79         /* The CPDO functions used to always set the destination type
  80            to be the same as their working size. */
  81
  82         if (nRc != 0) {
  83                 /* If the operation succeeded, check to see if the result in the
  84                    destination register is the correct size.  If not force it
  85                    to be. */
  86
  87                 fpa11->fType[getFd(opcode)] = nDest;
  88
  89 #ifdef CONFIG_FPE_NWFPE_XP
  90                 if (nDest != nType) {
  91                         switch (nDest) {
  92                         case typeSingle:
  93                                 {
  94                                         if (typeDouble == nType)
  95                                                 rFd->fSingle = float64_to_float32(rFd->fDouble);
  96                                         else
  97                                                 rFd->fSingle = floatx80_to_float32(rFd->fExtended);
  98                                 }
  99                                 break;
 100
 101                         case typeDouble:
 102                                 {
 103                                         if (typeSingle == nType)
 104                                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 105                                         else
 106                                                 rFd->fDouble = floatx80_to_float64(rFd->fExtended);
 107                                 }
 108                                 break;
 109
 110                         case typeExtended:
 111                                 {
 112                                         if (typeSingle == nType)
 113                                                 rFd->fExtended = float32_to_floatx80(rFd->fSingle);
 114                                         else
 115                                                 rFd->fExtended = float64_to_floatx80(rFd->fDouble);
 116                                 }
 117                                 break;
 118                         }
 119                 }
 120 #else
 121                 if (nDest != nType) {
 122                         if (nDest == typeSingle)
 123                                 rFd->fSingle = float64_to_float32(rFd->fDouble);
 124                         else
 125                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 126                 }
 127 #endif
 128         }
 129
 130         return nRc;
 131 }