gdb/gdbserver/i387-fp.c

   1 /* i387-specific utility functions, for the remote server for GDB.
   2    Copyright (C) 2000, 2001, 2002, 2005, 2007, 2008, 2009
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "server.h"
  21 #include "i387-fp.h"
  22
  23 int num_xmm_registers = 8;
  24
  25 /* Note: These functions preserve the reserved bits in control registers.
  26    However, gdbserver promptly throws away that information.  */
  27
  28 /* These structs should have the proper sizes and alignment on both
  29    i386 and x86-64 machines.  */
  30
  31 struct i387_fsave {
  32   /* All these are only sixteen bits, plus padding, except for fop (which
  33      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  34   unsigned short fctrl;
  35   unsigned short pad1;
  36   unsigned short fstat;
  37   unsigned short pad2;
  38   unsigned short ftag;
  39   unsigned short pad3;
  40   unsigned int fioff;
  41   unsigned short fiseg;
  42   unsigned short fop;
  43   unsigned int fooff;
  44   unsigned short foseg;
  45   unsigned short pad4;
  46
  47   /* Space for eight 80-bit FP values.  */
  48   unsigned char st_space[80];
  49 };
  50
  51 struct i387_fxsave {
  52   /* All these are only sixteen bits, plus padding, except for fop (which
  53      is only eleven bits), and fooff / fioff (which are 32 bits each).  */
  54   unsigned short fctrl;
  55   unsigned short fstat;
  56   unsigned short ftag;
  57   unsigned short fop;
  58   unsigned int fioff;
  59   unsigned short fiseg;
  60   unsigned short pad1;
  61   unsigned int fooff;
  62   unsigned short foseg;
  63   unsigned short pad12;
  64
  65   unsigned int mxcsr;
  66   unsigned int pad3;
  67
  68   /* Space for eight 80-bit FP values in 128-bit spaces.  */
  69   unsigned char st_space[128];
  70
  71   /* Space for eight 128-bit XMM values, or 16 on x86-64.  */
  72   unsigned char xmm_space[256];
  73 };
  74
  75 void
  76 i387_cache_to_fsave (void *buf)
  77 {
  78   struct i387_fsave *fp = (struct i387_fsave *) buf;
  79   int i;
  80   int st0_regnum = find_regno ("st0");
  81   unsigned long val, val2;
  82
  83   for (i = 0; i < 8; i++)
  84     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
  85
  86   collect_register_by_name ("fioff", &fp->fioff);
  87   collect_register_by_name ("fooff", &fp->fooff);
  88
  89   /* This one's 11 bits... */
  90   collect_register_by_name ("fop", &val2);
  91   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
  92
  93   /* Some registers are 16-bit.  */
  94   collect_register_by_name ("fctrl", &val);
  95   fp->fctrl = val;
  96
  97   collect_register_by_name ("fstat", &val);
  98   val &= 0xFFFF;
  99   fp->fstat = val;
 100
 101   collect_register_by_name ("ftag", &val);
 102   val &= 0xFFFF;
 103   fp->ftag = val;
 104
 105   collect_register_by_name ("fiseg", &val);
 106   val &= 0xFFFF;
 107   fp->fiseg = val;
 108
 109   collect_register_by_name ("foseg", &val);
 110   val &= 0xFFFF;
 111   fp->foseg = val;
 112 }
 113
 114 void
 115 i387_fsave_to_cache (const void *buf)
 116 {
 117   struct i387_fsave *fp = (struct i387_fsave *) buf;
 118   int i;
 119   int st0_regnum = find_regno ("st0");
 120   unsigned long val;
 121
 122   for (i = 0; i < 8; i++)
 123     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 10);
 124
 125   supply_register_by_name ("fioff", &fp->fioff);
 126   supply_register_by_name ("fooff", &fp->fooff);
 127
 128   /* Some registers are 16-bit.  */
 129   val = fp->fctrl & 0xFFFF;
 130   supply_register_by_name ("fctrl", &val);
 131
 132   val = fp->fstat & 0xFFFF;
 133   supply_register_by_name ("fstat", &val);
 134
 135   val = fp->ftag & 0xFFFF;
 136   supply_register_by_name ("ftag", &val);
 137
 138   val = fp->fiseg & 0xFFFF;
 139   supply_register_by_name ("fiseg", &val);
 140
 141   val = fp->foseg & 0xFFFF;
 142   supply_register_by_name ("foseg", &val);
 143
 144   /* fop has only 11 valid bits.  */
 145   val = (fp->fop) & 0x7FF;
 146   supply_register_by_name ("fop", &val);
 147 }
 148
 149 void
 150 i387_cache_to_fxsave (void *buf)
 151 {
 152   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 153   int i;
 154   int st0_regnum = find_regno ("st0");
 155   int xmm0_regnum = find_regno ("xmm0");
 156   unsigned long val, val2;
 157
 158   for (i = 0; i < 8; i++)
 159     collect_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 160   for (i = 0; i < num_xmm_registers; i++)
 161     collect_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 162
 163   collect_register_by_name ("fioff", &fp->fioff);
 164   collect_register_by_name ("fooff", &fp->fooff);
 165   collect_register_by_name ("mxcsr", &fp->mxcsr);
 166
 167   /* This one's 11 bits... */
 168   collect_register_by_name ("fop", &val2);
 169   fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);
 170
 171   /* Some registers are 16-bit.  */
 172   collect_register_by_name ("fctrl", &val);
 173   fp->fctrl = val;
 174
 175   collect_register_by_name ("fstat", &val);
 176   fp->fstat = val;
 177
 178   /* Convert to the simplifed tag form stored in fxsave data.  */
 179   collect_register_by_name ("ftag", &val);
 180   val &= 0xFFFF;
 181   val2 = 0;
 182   for (i = 7; i >= 0; i--)
 183     {
 184       int tag = (val >> (i * 2)) & 3;
 185
 186       if (tag != 3)
 187         val2 |= (1 << i);
 188     }
 189   fp->ftag = val2;
 190
 191   collect_register_by_name ("fiseg", &val);
 192   fp->fiseg = val;
 193
 194   collect_register_by_name ("foseg", &val);
 195   fp->foseg = val;
 196 }
 197
 198 static int
 199 i387_ftag (struct i387_fxsave *fp, int regno)
 200 {
 201   unsigned char *raw = &fp->st_space[regno * 16];
 202   unsigned int exponent;
 203   unsigned long fraction[2];
 204   int integer;
 205
 206   integer = raw[7] & 0x80;
 207   exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
 208   fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
 209   fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
 210                  | (raw[5] << 8) | raw[4]);
 211
 212   if (exponent == 0x7fff)
 213     {
 214       /* Special.  */
 215       return (2);
 216     }
 217   else if (exponent == 0x0000)
 218     {
 219       if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer)
 220         {
 221           /* Zero.  */
 222           return (1);
 223         }
 224       else
 225         {
 226           /* Special.  */
 227           return (2);
 228         }
 229     }
 230   else
 231     {
 232       if (integer)
 233         {
 234           /* Valid.  */
 235           return (0);
 236         }
 237       else
 238         {
 239           /* Special.  */
 240           return (2);
 241         }
 242     }
 243 }
 244
 245 void
 246 i387_fxsave_to_cache (const void *buf)
 247 {
 248   struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 249   int i, top;
 250   int st0_regnum = find_regno ("st0");
 251   int xmm0_regnum = find_regno ("xmm0");
 252   unsigned long val;
 253
 254   for (i = 0; i < 8; i++)
 255     supply_register (i + st0_regnum, ((char *) &fp->st_space[0]) + i * 16);
 256   for (i = 0; i < num_xmm_registers; i++)
 257     supply_register (i + xmm0_regnum, ((char *) &fp->xmm_space[0]) + i * 16);
 258
 259   supply_register_by_name ("fioff", &fp->fioff);
 260   supply_register_by_name ("fooff", &fp->fooff);
 261   supply_register_by_name ("mxcsr", &fp->mxcsr);
 262
 263   /* Some registers are 16-bit.  */
 264   val = fp->fctrl & 0xFFFF;
 265   supply_register_by_name ("fctrl", &val);
 266
 267   val = fp->fstat & 0xFFFF;
 268   supply_register_by_name ("fstat", &val);
 269
 270   /* Generate the form of ftag data that GDB expects.  */
 271   top = (fp->fstat >> 11) & 0x7;
 272   val = 0;
 273   for (i = 7; i >= 0; i--)
 274     {
 275       int tag;
 276       if (fp->ftag & (1 << i))
 277         tag = i387_ftag (fp, (i + 8 - top) % 8);
 278       else
 279         tag = 3;
 280       val |= tag << (2 * i);
 281     }
 282   supply_register_by_name ("ftag", &val);
 283
 284   val = fp->fiseg & 0xFFFF;
 285   supply_register_by_name ("fiseg", &val);
 286
 287   val = fp->foseg & 0xFFFF;
 288   supply_register_by_name ("foseg", &val);
 289
 290   val = (fp->fop) & 0x7FF;
 291   supply_register_by_name ("fop", &val);
 292 }