git.oblomov.eu Git - linux-2.6/blob - 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(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
  27 unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
  28 unsigned int ExtendedCPDO(struct roundingData *roundData, 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         struct roundingData roundData;
  36
  37         /* Get the destination size.  If not valid let Linux perform
  38            an invalid instruction trap. */
  39         nDest = getDestinationSize(opcode);
  40         if (typeNone == nDest)
  41                 return 0;
  42
  43         roundData.mode = SetRoundingMode(opcode);
  44         roundData.precision = SetRoundingPrecision(opcode);
  45         roundData.exception = 0;
  46
  47         /* Compare the size of the operands in Fn and Fm.
  48            Choose the largest size and perform operations in that size,
  49            in order to make use of all the precision of the operands.
  50            If Fm is a constant, we just grab a constant of a size
  51            matching the size of the operand in Fn. */
  52         if (MONADIC_INSTRUCTION(opcode))
  53                 nType = nDest;
  54         else
  55                 nType = fpa11->fType[getFn(opcode)];
  56
  57         if (!CONSTANT_FM(opcode)) {
  58                 register unsigned int Fm = getFm(opcode);
  59                 if (nType < fpa11->fType[Fm]) {
  60                         nType = fpa11->fType[Fm];
  61                 }
  62         }
  63
  64         rFd = &fpa11->fpreg[getFd(opcode)];
  65
  66         switch (nType) {
  67         case typeSingle:
  68                 nRc = SingleCPDO(&roundData, opcode, rFd);
  69                 break;
  70         case typeDouble:
  71                 nRc = DoubleCPDO(&roundData, opcode, rFd);
  72                 break;
  73 #ifdef CONFIG_FPE_NWFPE_XP
  74         case typeExtended:
  75                 nRc = ExtendedCPDO(&roundData, opcode, rFd);
  76                 break;
  77 #endif
  78         default:
  79                 nRc = 0;
  80         }
  81
  82         /* The CPDO functions used to always set the destination type
  83            to be the same as their working size. */
  84
  85         if (nRc != 0) {
  86                 /* If the operation succeeded, check to see if the result in the
  87                    destination register is the correct size.  If not force it
  88                    to be. */
  89
  90                 fpa11->fType[getFd(opcode)] = nDest;
  91
  92 #ifdef CONFIG_FPE_NWFPE_XP
  93                 if (nDest != nType) {
  94                         switch (nDest) {
  95                         case typeSingle:
  96                                 {
  97                                         if (typeDouble == nType)
  98                                                 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
  99                                         else
 100                                                 rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
 101                                 }
 102                                 break;
 103
 104                         case typeDouble:
 105                                 {
 106                                         if (typeSingle == nType)
 107                                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 108                                         else
 109                                                 rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
 110                                 }
 111                                 break;
 112
 113                         case typeExtended:
 114                                 {
 115                                         if (typeSingle == nType)
 116                                                 rFd->fExtended = float32_to_floatx80(rFd->fSingle);
 117                                         else
 118                                                 rFd->fExtended = float64_to_floatx80(rFd->fDouble);
 119                                 }
 120                                 break;
 121                         }
 122                 }
 123 #else
 124                 if (nDest != nType) {
 125                         if (nDest == typeSingle)
 126                                 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
 127                         else
 128                                 rFd->fDouble = float32_to_float64(rFd->fSingle);
 129                 }
 130 #endif
 131         }
 132
 133         if (roundData.exception)
 134                 float_raise(roundData.exception);
 135
 136         return nRc;
 137 }