gnu/dist/gdb6/gdb/gdbserver/i387-fp.c

   1 /* i387-specific utility functions, for the remote server for GDB.
   2    Copyright (C) 2000, 2001, 2002, 2005
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   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., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "server.h"
  23 #include "i387-fp.h"
  24
  25 int num_xmm_registers = 8;
  26
  27 /* Note: These functions preserve the reserved bits in control registers.
  28    However, gdbserver promptly throws away that information.  */
  29
  30 /* These structs should have the proper sizes and alignment on both
  31    i386 and x86-64 machines.  */
  32
  33 struct i387_fsave {
  34   /* All these are only sixteen bits, plus padding, except for fop (which
  35      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  36   unsigned int fctrl;
  37   unsigned int fstat;
  38   unsigned int ftag;
  39   unsigned int fioff;
  40   unsigned short fiseg;
  41   unsigned short fop;
  42   unsigned int fooff;
  43   unsigned int foseg;
  44
  45   /* Space for eight 80-bit FP values.  */
  46   unsigned char st_space[80];
  47 };
  48
  49 struct i387_fxsave {
  50   /* All these are only sixteen bits, plus padding, except for fop (which
  51      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  52   unsigned short fctrl;
  53   unsigned short fstat;
  54   unsigned short ftag;
  55   unsigned short fop;
  56   unsigned int fioff;
  57   unsigned int fiseg;
  58   unsigned int fooff;
  59   unsigned int foseg;
  60
  61   unsigned int mxcsr;
  62
  63   unsigned int _pad1;
  64
  65   /* Space for eight 80-bit FP values in 128-bit spaces.  */
  66   unsigned char st_space[128];
  67
  68   /* Space for eight 128-bit XMM values, or 16 on x86-64.  */
  69   unsigned char xmm_space[256];
  70 };
  71
  72 void
  73 i387_cache_to_fsave (void *buf)
  74 {
  75   struct i387_fsave *fp = (struct i387_fsave *) buf;
  76   int i;
  77   int st0_regnum = find_regno ("st0");
  78   unsigned long val, val2;
  79
  80   for (i = 0; i < 8; i++)
  81     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
  82
  83   collect_register_by_name ("fioff", &fp->fioff);
  84   collect_register_by_name ("fooff", &fp->fooff);
  85
  86   /* This one's 11 bits... */
  87   collect_register_by_name ("fop", &val2);
  88   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
  89
  90   /* Some registers are 16-bit.  */
  91   collect_register_by_name ("fctrl", &val);
  92   *(unsigned short *) &fp->fctrl = val;
  93
  94   collect_register_by_name ("fstat", &val);
  95   val &= 0xFFFF;
  96   *(unsigned short *) &fp->fstat = val;
  97
  98   collect_register_by_name ("ftag", &val);
  99   val &= 0xFFFF;
 100   *(unsigned short *) &fp->ftag = val;
 101
 102   collect_register_by_name ("fiseg", &val);
 103   val &= 0xFFFF;
 104   *(unsigned short *) &fp->fiseg = val;
 105
 106   collect_register_by_name ("foseg", &val);
 107   val &= 0xFFFF;
 108   *(unsigned short *) &fp->foseg = val;
 109 }
 110
 111 void
 112 i387_fsave_to_cache (const void *buf)
 113 {
 114   struct i387_fsave *fp = (struct i387_fsave *) buf;
 115   int i;
 116   int st0_regnum = find_regno ("st0");
 117   unsigned long val;
 118
 119   for (i = 0; i < 8; i++)
 120     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
 121
 122   supply_register_by_name ("fioff", &fp->fioff);
 123   supply_register_by_name ("fooff", &fp->fooff);
 124
 125   /* Some registers are 16-bit.  */
 126   val = fp->fctrl & 0xFFFF;
 127   supply_register_by_name ("fctrl", &val);
 128
 129   val = fp->fstat & 0xFFFF;
 130   supply_register_by_name ("fstat", &val);
 131
 132   val = fp->ftag & 0xFFFF;
 133   supply_register_by_name ("ftag", &val);
 134
 135   val = fp->fiseg & 0xFFFF;
 136   supply_register_by_name ("fiseg", &val);
 137
 138   val = fp->foseg & 0xFFFF;
 139   supply_register_by_name ("foseg", &val);
 140
 141   val = (fp->fop) & 0x7FF;
 142   supply_register_by_name ("fop", &val);
 143 }
 144
 145 void
 146 i387_cache_to_fxsave (void *buf)
 147 {
 148   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 149   int i;
 150   int st0_regnum = find_regno ("st0");
 151   int xmm0_regnum = find_regno ("xmm0");
 152   unsigned long val, val2;
 153
 154   for (i = 0; i < 8; i++)
 155     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 156   for (i = 0; i < num_xmm_registers; i++)
 157     collect_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 158
 159   collect_register_by_name ("fioff", &fp->fioff);
 160   collect_register_by_name ("fooff", &fp->fooff);
 161   collect_register_by_name ("mxcsr", &fp->mxcsr);
 162
 163   /* This one's 11 bits... */
 164   collect_register_by_name ("fop", &val2);
 165   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
 166
 167   /* Some registers are 16-bit.  */
 168   collect_register_by_name ("fctrl", &val);
 169   *(unsigned short *) &fp->fctrl = val;
 170
 171   collect_register_by_name ("fstat", &val);
 172   val &= 0xFFFF;
 173   *(unsigned short *) &fp->fstat = val;
 174
 175   /* Convert to the simplifed tag form stored in fxsave data.  */
 176   collect_register_by_name ("ftag", &val);
 177   val &= 0xFFFF;
 178   for (i = 7; i >= 0; i--)
 179     {
 180       int tag = (val >> (i * 2)) & 3;
 181
 182       if (tag != 3)
 183         val2 |= (1 << i);
 184     }
 185   *(unsigned short *) &fp->ftag = val2;
 186
 187   collect_register_by_name ("fiseg", &val);
 188   val &= 0xFFFF;
 189   *(unsigned short *) &fp->fiseg = val;
 190
 191   collect_register_by_name ("foseg", &val);
 192   val &= 0xFFFF;
 193   *(unsigned short *) &fp->foseg = val;
 194 }
 195
 196 static int
 197 i387_ftag (struct i387_fxsave *fp, int regno)
 198 {
 199   unsigned char *raw = &fp->st_space[regno * 16];
 200   unsigned int exponent;
 201   unsigned long fraction[2];
 202   int integer;
 203
 204   integer = raw[7] & 0x80;
 205   exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
 206   fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
 207   fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
 208                  | (raw[5] << 8) | raw[4]);
 209
 210   if (exponent == 0x7fff)
 211     {
 212       /* Special.  */
 213       return (2);
 214     }
 215   else if (exponent == 0x0000)
 216     {
 217       if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer)
 218         {
 219           /* Zero.  */
 220           return (1);
 221         }
 222       else
 223         {
 224           /* Special.  */
 225           return (2);
 226         }
 227     }
 228   else
 229     {
 230       if (integer)
 231         {
 232           /* Valid.  */
 233           return (0);
 234         }
 235       else
 236         {
 237           /* Special.  */
 238           return (2);
 239         }
 240     }
 241 }
 242
 243 void
 244 i387_fxsave_to_cache (const void *buf)
 245 {
 246   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 247   int i, top;
 248   int st0_regnum = find_regno ("st0");
 249   int xmm0_regnum = find_regno ("xmm0");
 250   unsigned long val;
 251
 252   for (i = 0; i < 8; i++)
 253     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 254   for (i = 0; i < num_xmm_registers; i++)
 255     supply_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 256
 257   supply_register_by_name ("fioff", &fp->fioff);
 258   supply_register_by_name ("fooff", &fp->fooff);
 259   supply_register_by_name ("mxcsr", &fp->mxcsr);
 260
 261   /* Some registers are 16-bit.  */
 262   val = fp->fctrl & 0xFFFF;
 263   supply_register_by_name ("fctrl", &val);
 264
 265   val = fp->fstat & 0xFFFF;
 266   supply_register_by_name ("fstat", &val);
 267
 268   /* Generate the form of ftag data that GDB expects.  */
 269   top = (fp->fstat >> 11) & 0x7;
 270   val = 0;
 271   for (i = 7; i >= 0; i--)
 272     {
 273       int tag;
 274       if (val & (1 << i))
 275         tag = i387_ftag (fp, (i + 8 - top) % 8);
 276       else
 277         tag = 3;
 278       val |= tag << (2 * i);
 279     }
 280   supply_register_by_name ("ftag", &val);
 281
 282   val = fp->fiseg & 0xFFFF;
 283   supply_register_by_name ("fiseg", &val);
 284
 285   val = fp->foseg & 0xFFFF;
 286   supply_register_by_name ("foseg", &val);
 287
 288   val = (fp->fop) & 0x7FF;
 289   supply_register_by_name ("fop", &val);
 290 }