arch/arm26/nwfpe/fpopcode.c

   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, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "fpa11.h"
  23 #include "softfloat.h"
  24 #include "fpopcode.h"
  25 #include "fpsr.h"
  26 #include "fpmodule.h"
  27 #include "fpmodule.inl"
  28
  29 const floatx80 floatx80Constant[] = {
  30   { 0x0000, 0x0000000000000000ULL},     /* extended 0.0 */
  31   { 0x3fff, 0x8000000000000000ULL},     /* extended 1.0 */
  32   { 0x4000, 0x8000000000000000ULL},     /* extended 2.0 */
  33   { 0x4000, 0xc000000000000000ULL},     /* extended 3.0 */
  34   { 0x4001, 0x8000000000000000ULL},     /* extended 4.0 */
  35   { 0x4001, 0xa000000000000000ULL},     /* extended 5.0 */
  36   { 0x3ffe, 0x8000000000000000ULL},     /* extended 0.5 */
  37   { 0x4002, 0xa000000000000000ULL}      /* extended 10.0 */
  38 };
  39
  40 const float64 float64Constant[] = {
  41   0x0000000000000000ULL,                /* double 0.0 */
  42   0x3ff0000000000000ULL,                /* double 1.0 */
  43   0x4000000000000000ULL,                /* double 2.0 */
  44   0x4008000000000000ULL,                /* double 3.0 */
  45   0x4010000000000000ULL,                /* double 4.0 */
  46   0x4014000000000000ULL,                /* double 5.0 */
  47   0x3fe0000000000000ULL,                /* double 0.5 */
  48   0x4024000000000000ULL                 /* double 10.0 */
  49 };
  50
  51 const float32 float32Constant[] = {
  52   0x00000000,                           /* single 0.0 */
  53   0x3f800000,                           /* single 1.0 */
  54   0x40000000,                           /* single 2.0 */
  55   0x40400000,                           /* single 3.0 */
  56   0x40800000,                           /* single 4.0 */
  57   0x40a00000,                           /* single 5.0 */
  58   0x3f000000,                           /* single 0.5 */
  59   0x41200000                            /* single 10.0 */
  60 };
  61
  62 unsigned int getTransferLength(const unsigned int opcode)
  63 {
  64   unsigned int nRc;
  65
  66   switch (opcode & MASK_TRANSFER_LENGTH)
  67   {
  68     case 0x00000000: nRc = 1; break; /* single precision */
  69     case 0x00008000: nRc = 2; break; /* double precision */
  70     case 0x00400000: nRc = 3; break; /* extended precision */
  71     default: nRc = 0;
  72   }
  73
  74   return(nRc);
  75 }
  76
  77 unsigned int getRegisterCount(const unsigned int opcode)
  78 {
  79   unsigned int nRc;
  80
  81   switch (opcode & MASK_REGISTER_COUNT)
  82   {
  83     case 0x00000000: nRc = 4; break;
  84     case 0x00008000: nRc = 1; break;
  85     case 0x00400000: nRc = 2; break;
  86     case 0x00408000: nRc = 3; break;
  87     default: nRc = 0;
  88   }
  89
  90   return(nRc);
  91 }
  92
  93 unsigned int getRoundingPrecision(const unsigned int opcode)
  94 {
  95   unsigned int nRc;
  96
  97   switch (opcode & MASK_ROUNDING_PRECISION)
  98   {
  99     case 0x00000000: nRc = 1; break;
 100     case 0x00000080: nRc = 2; break;
 101     case 0x00080000: nRc = 3; break;
 102     default: nRc = 0;
 103   }
 104
 105   return(nRc);
 106 }
 107
 108 unsigned int getDestinationSize(const unsigned int opcode)
 109 {
 110   unsigned int nRc;
 111
 112   switch (opcode & MASK_DESTINATION_SIZE)
 113   {
 114     case 0x00000000: nRc = typeSingle; break;
 115     case 0x00000080: nRc = typeDouble; break;
 116     case 0x00080000: nRc = typeExtended; break;
 117     default: nRc = typeNone;
 118   }
 119
 120   return(nRc);
 121 }
 122
 123 /* condition code lookup table
 124  index into the table is test code: EQ, NE, ... LT, GT, AL, NV
 125  bit position in short is condition code: NZCV */
 126 static const unsigned short aCC[16] = {
 127     0xF0F0, // EQ == Z set
 128     0x0F0F, // NE
 129     0xCCCC, // CS == C set
 130     0x3333, // CC
 131     0xFF00, // MI == N set
 132     0x00FF, // PL
 133     0xAAAA, // VS == V set
 134     0x5555, // VC
 135     0x0C0C, // HI == C set && Z clear
 136     0xF3F3, // LS == C clear || Z set
 137     0xAA55, // GE == (N==V)
 138     0x55AA, // LT == (N!=V)
 139     0x0A05, // GT == (!Z && (N==V))
 140     0xF5FA, // LE == (Z || (N!=V))
 141     0xFFFF, // AL always
 142     0 // NV
 143 };
 144
 145 unsigned int checkCondition(const unsigned int opcode, const unsigned int ccodes)
 146 {
 147   return (aCC[opcode>>28] >> (ccodes>>28)) & 1;
 148 }