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 int fctrl;
  36   unsigned int fstat;
  37   unsigned int ftag;
  38   unsigned int fioff;
  39   unsigned short fiseg;
  40   unsigned short fop;
  41   unsigned int fooff;
  42   unsigned int foseg;
  43
  44   /* Space for eight 80-bit FP values.  */
  45   unsigned char st_space[80];
  46 };
  47
  48 struct i387_fxsave {
  49   /* All these are only sixteen bits, plus padding, except for fop (which
  50      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  51   unsigned short fctrl;
  52   unsigned short fstat;
  53   unsigned short ftag;
  54   unsigned short fop;
  55   unsigned int fioff;
  56   unsigned int fiseg;
  57   unsigned int fooff;
  58   unsigned int foseg;
  59
  60   unsigned int mxcsr;
  61
  62   unsigned int _pad1;
  63
  64   /* Space for eight 80-bit FP values in 128-bit spaces.  */
  65   unsigned char st_space[128];
  66
  67   /* Space for eight 128-bit XMM values, or 16 on x86-64.  */
  68   unsigned char xmm_space[256];
  69 };
  70
  71 void
  72 i387_cache_to_fsave (void *buf)
  73 {
  74   struct i387_fsave *fp = (struct i387_fsave *) buf;
  75   int i;
  76   int st0_regnum = find_regno ("st0");
  77   unsigned long val, val2;
  78
  79   for (i = 0; i < 8; i++)
  80     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
  81
  82   collect_register_by_name ("fioff", &fp->fioff);
  83   collect_register_by_name ("fooff", &fp->fooff);
  84
  85   /* This one's 11 bits... */
  86   collect_register_by_name ("fop", &val2);
  87   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
  88
  89   /* Some registers are 16-bit.  */
  90   collect_register_by_name ("fctrl", &val);
  91   *(unsigned short *) &fp->fctrl = val;
  92
  93   collect_register_by_name ("fstat", &val);
  94   val &= 0xFFFF;
  95   *(unsigned short *) &fp->fstat = val;
  96
  97   collect_register_by_name ("ftag", &val);
  98   val &= 0xFFFF;
  99   *(unsigned short *) &fp->ftag = val;
 100
 101   collect_register_by_name ("fiseg", &val);
 102   val &= 0xFFFF;
 103   *(unsigned short *) &fp->fiseg = val;
 104
 105   collect_register_by_name ("foseg", &val);
 106   val &= 0xFFFF;
 107   *(unsigned short *) &fp->foseg = val;
 108 }
 109
 110 void
 111 i387_fsave_to_cache (const void *buf)
 112 {
 113   struct i387_fsave *fp = (struct i387_fsave *) buf;
 114   int i;
 115   int st0_regnum = find_regno ("st0");
 116   unsigned long val;
 117
 118   for (i = 0; i < 8; i++)
 119     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
 120
 121   supply_register_by_name ("fioff", &fp->fioff);
 122   supply_register_by_name ("fooff", &fp->fooff);
 123
 124   /* Some registers are 16-bit.  */
 125   val = fp->fctrl & 0xFFFF;
 126   supply_register_by_name ("fctrl", &val);
 127
 128   val = fp->fstat & 0xFFFF;
 129   supply_register_by_name ("fstat", &val);
 130
 131   val = fp->ftag & 0xFFFF;
 132   supply_register_by_name ("ftag", &val);
 133
 134   val = fp->fiseg & 0xFFFF;
 135   supply_register_by_name ("fiseg", &val);
 136
 137   val = fp->foseg & 0xFFFF;
 138   supply_register_by_name ("foseg", &val);
 139
 140   val = (fp->fop) & 0x7FF;
 141   supply_register_by_name ("fop", &val);
 142 }
 143
 144 void
 145 i387_cache_to_fxsave (void *buf)
 146 {
 147   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 148   int i;
 149   int st0_regnum = find_regno ("st0");
 150   int xmm0_regnum = find_regno ("xmm0");
 151   unsigned long val, val2;
 152
 153   for (i = 0; i < 8; i++)
 154     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 155   for (i = 0; i < num_xmm_registers; i++)
 156     collect_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 157
 158   collect_register_by_name ("fioff", &fp->fioff);
 159   collect_register_by_name ("fooff", &fp->fooff);
 160   collect_register_by_name ("mxcsr", &fp->mxcsr);
 161
 162   /* This one's 11 bits... */
 163   collect_register_by_name ("fop", &val2);
 164   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
 165
 166   /* Some registers are 16-bit.  */
 167   collect_register_by_name ("fctrl", &val);
 168   *(unsigned short *) &fp->fctrl = val;
 169
 170   collect_register_by_name ("fstat", &val);
 171   val &= 0xFFFF;
 172   *(unsigned short *) &fp->fstat = val;
 173
 174   /* Convert to the simplifed tag form stored in fxsave data.  */
 175   collect_register_by_name ("ftag", &val);
 176   val &= 0xFFFF;
 177   val2 = 0;
 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 (fp->ftag & (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 }