gdb/gdbserver/i387-fp.c

   1 /* i387-specific utility functions, for the remote server for GDB.
   2    Copyright (C) 2000, 2001, 2002, 2005, 2007 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19    Boston, MA 02110-1301, USA.  */
  20
  21 #include "server.h"
  22 #include "i387-fp.h"
  23
  24 int num_xmm_registers = 8;
  25
  26 /* Note: These functions preserve the reserved bits in control registers.
  27    However, gdbserver promptly throws away that information.  */
  28
  29 /* These structs should have the proper sizes and alignment on both
  30    i386 and x86-64 machines.  */
  31
  32 struct i387_fsave {
  33   /* All these are only sixteen bits, plus padding, except for fop (which
  34      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  35   unsigned short fctrl;
  36   unsigned short pad1;
  37   unsigned short fstat;
  38   unsigned short pad2;
  39   unsigned short ftag;
  40   unsigned short pad3;
  41   unsigned int fioff;
  42   unsigned short fiseg;
  43   unsigned short fop;
  44   unsigned int fooff;
  45   unsigned short foseg;
  46   unsigned short pad4;
  47
  48   /* Space for eight 80-bit FP values.  */
  49   unsigned char st_space[80];
  50 };
  51
  52 struct i387_fxsave {
  53   /* All these are only sixteen bits, plus padding, except for fop (which
  54      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  55   unsigned short fctrl;
  56   unsigned short fstat;
  57   unsigned short ftag;
  58   unsigned short fop;
  59   unsigned int fioff;
  60   unsigned short fiseg;
  61   unsigned short pad1;
  62   unsigned int fooff;
  63   unsigned short foseg;
  64   unsigned short pad12;
  65
  66   unsigned int mxcsr;
  67   unsigned int pad3;
  68
  69   /* Space for eight 80-bit FP values in 128-bit spaces.  */
  70   unsigned char st_space[128];
  71
  72   /* Space for eight 128-bit XMM values, or 16 on x86-64.  */
  73   unsigned char xmm_space[256];
  74 };
  75
  76 void
  77 i387_cache_to_fsave (void *buf)
  78 {
  79   struct i387_fsave *fp = (struct i387_fsave *) buf;
  80   int i;
  81   int st0_regnum = find_regno ("st0");
  82   unsigned long val, val2;
  83
  84   for (i = 0; i < 8; i++)
  85     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
  86
  87   collect_register_by_name ("fioff", &fp->fioff);
  88   collect_register_by_name ("fooff", &fp->fooff);
  89
  90   /* This one's 11 bits... */
  91   collect_register_by_name ("fop", &val2);
  92   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
  93
  94   /* Some registers are 16-bit.  */
  95   collect_register_by_name ("fctrl", &val);
  96   fp->fctrl = val;
  97
  98   collect_register_by_name ("fstat", &val);
  99   val &= 0xFFFF;
 100   fp->fstat = val;
 101
 102   collect_register_by_name ("ftag", &val);
 103   val &= 0xFFFF;
 104   fp->ftag = val;
 105
 106   collect_register_by_name ("fiseg", &val);
 107   val &= 0xFFFF;
 108   fp->fiseg = val;
 109
 110   collect_register_by_name ("foseg", &val);
 111   val &= 0xFFFF;
 112   fp->foseg = val;
 113 }
 114
 115 void
 116 i387_fsave_to_cache (const void *buf)
 117 {
 118   struct i387_fsave *fp = (struct i387_fsave *) buf;
 119   int i;
 120   int st0_regnum = find_regno ("st0");
 121   unsigned long val;
 122
 123   for (i = 0; i < 8; i++)
 124     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
 125
 126   supply_register_by_name ("fioff", &fp->fioff);
 127   supply_register_by_name ("fooff", &fp->fooff);
 128
 129   /* Some registers are 16-bit.  */
 130   val = fp->fctrl & 0xFFFF;
 131   supply_register_by_name ("fctrl", &val);
 132
 133   val = fp->fstat & 0xFFFF;
 134   supply_register_by_name ("fstat", &val);
 135
 136   val = fp->ftag & 0xFFFF;
 137   supply_register_by_name ("ftag", &val);
 138
 139   val = fp->fiseg & 0xFFFF;
 140   supply_register_by_name ("fiseg", &val);
 141
 142   val = fp->foseg & 0xFFFF;
 143   supply_register_by_name ("foseg", &val);
 144
 145   /* fop has only 11 valid bits.  */
 146   val = (fp->fop) & 0x7FF;
 147   supply_register_by_name ("fop", &val);
 148 }
 149
 150 void
 151 i387_cache_to_fxsave (void *buf)
 152 {
 153   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 154   int i;
 155   int st0_regnum = find_regno ("st0");
 156   int xmm0_regnum = find_regno ("xmm0");
 157   unsigned long val, val2;
 158
 159   for (i = 0; i < 8; i++)
 160     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 161   for (i = 0; i < num_xmm_registers; i++)
 162     collect_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 163
 164   collect_register_by_name ("fioff", &fp->fioff);
 165   collect_register_by_name ("fooff", &fp->fooff);
 166   collect_register_by_name ("mxcsr", &fp->mxcsr);
 167
 168   /* This one's 11 bits... */
 169   collect_register_by_name ("fop", &val2);
 170   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
 171
 172   /* Some registers are 16-bit.  */
 173   collect_register_by_name ("fctrl", &val);
 174   fp->fctrl = val;
 175
 176   collect_register_by_name ("fstat", &val);
 177   fp->fstat = val;
 178
 179   /* Convert to the simplifed tag form stored in fxsave data.  */
 180   collect_register_by_name ("ftag", &val);
 181   val &= 0xFFFF;
 182   val2 = 0;
 183   for (i = 7; i >= 0; i--)
 184     {
 185       int tag = (val >> (i * 2)) & 3;
 186
 187       if (tag != 3)
 188         val2 |= (1 << i);
 189     }
 190   fp->ftag = val2;
 191
 192   collect_register_by_name ("fiseg", &val);
 193   fp->fiseg = val;
 194
 195   collect_register_by_name ("foseg", &val);
 196   fp->foseg = val;
 197 }
 198
 199 static int
 200 i387_ftag (struct i387_fxsave *fp, int regno)
 201 {
 202   unsigned char *raw = &fp->st_space[regno * 16];
 203   unsigned int exponent;
 204   unsigned long fraction[2];
 205   int integer;
 206
 207   integer = raw[7] & 0x80;
 208   exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
 209   fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
 210   fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
 211                  | (raw[5] << 8) | raw[4]);
 212
 213   if (exponent == 0x7fff)
 214     {
 215       /* Special.  */
 216       return (2);
 217     }
 218   else if (exponent == 0x0000)
 219     {
 220       if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer)
 221         {
 222           /* Zero.  */
 223           return (1);
 224         }
 225       else
 226         {
 227           /* Special.  */
 228           return (2);
 229         }
 230     }
 231   else
 232     {
 233       if (integer)
 234         {
 235           /* Valid.  */
 236           return (0);
 237         }
 238       else
 239         {
 240           /* Special.  */
 241           return (2);
 242         }
 243     }
 244 }
 245
 246 void
 247 i387_fxsave_to_cache (const void *buf)
 248 {
 249   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 250   int i, top;
 251   int st0_regnum = find_regno ("st0");
 252   int xmm0_regnum = find_regno ("xmm0");
 253   unsigned long val;
 254
 255   for (i = 0; i < 8; i++)
 256     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 257   for (i = 0; i < num_xmm_registers; i++)
 258     supply_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 259
 260   supply_register_by_name ("fioff", &fp->fioff);
 261   supply_register_by_name ("fooff", &fp->fooff);
 262   supply_register_by_name ("mxcsr", &fp->mxcsr);
 263
 264   /* Some registers are 16-bit.  */
 265   val = fp->fctrl & 0xFFFF;
 266   supply_register_by_name ("fctrl", &val);
 267
 268   val = fp->fstat & 0xFFFF;
 269   supply_register_by_name ("fstat", &val);
 270
 271   /* Generate the form of ftag data that GDB expects.  */
 272   top = (fp->fstat >> 11) & 0x7;
 273   val = 0;
 274   for (i = 7; i >= 0; i--)
 275     {
 276       int tag;
 277       if (fp->ftag & (1 << i))
 278         tag = i387_ftag (fp, (i + 8 - top) % 8);
 279       else
 280         tag = 3;
 281       val |= tag << (2 * i);
 282     }
 283   supply_register_by_name ("ftag", &val);
 284
 285   val = fp->fiseg & 0xFFFF;
 286   supply_register_by_name ("fiseg", &val);
 287
 288   val = fp->foseg & 0xFFFF;
 289   supply_register_by_name ("foseg", &val);
 290
 291   val = (fp->fop) & 0x7FF;
 292   supply_register_by_name ("fop", &val);
 293 }