sysdeps/i386/fpu/fenv_private.h

   1 #ifndef FENV_PRIVATE_H
   2 #define FENV_PRIVATE_H 1
   3
   4 #include <fenv.h>
   5 #include <fpu_control.h>
   6
   7 #ifdef __SSE2_MATH__
   8 # define math_opt_barrier(x) \
   9   ({ __typeof(x) __x;                                   \
  10      if (sizeof (x) <= sizeof (double))                 \
  11        __asm ("" : "=x" (__x) : "0" (x));               \
  12      else                                               \
  13        __asm ("" : "=t" (__x) : "0" (x));               \
  14      __x; })
  15 # define math_force_eval(x) \
  16   do {                                                  \
  17     if (sizeof (x) <= sizeof (double))                  \
  18       __asm __volatile ("" : : "x" (x));                \
  19     else                                                \
  20       __asm __volatile ("" : : "f" (x));                \
  21   } while (0)
  22 #else
  23 # define math_opt_barrier(x) \
  24   ({ __typeof (x) __x;                                  \
  25      __asm ("" : "=t" (__x) : "0" (x));                 \
  26      __x; })
  27 # define math_force_eval(x) \
  28   do {                                                  \
  29     __typeof (x) __x = (x);                             \
  30     if (sizeof (x) <= sizeof (double))                  \
  31       __asm __volatile ("" : : "m" (__x));              \
  32     else                                                \
  33       __asm __volatile ("" : : "f" (__x));              \
  34   } while (0)
  35 #endif
  36
  37 /* This file is used by both the 32- and 64-bit ports.  The 64-bit port
  38    has a field in the fenv_t for the mxcsr; the 32-bit port does not.
  39    Instead, we (ab)use the only 32-bit field extant in the struct.  */
  40 #ifndef __x86_64__
  41 # define __mxcsr        __eip
  42 #endif
  43
  44
  45 /* All of these functions are private to libm, and are all used in pairs
  46    to save+change the fp state and restore the original state.  Thus we
  47    need not care for both the 387 and the sse unit, only the one we're
  48    actually using.  */
  49
  50 #if defined __AVX__ || defined SSE2AVX
  51 # define STMXCSR "vstmxcsr"
  52 # define LDMXCSR "vldmxcsr"
  53 #else
  54 # define STMXCSR "stmxcsr"
  55 # define LDMXCSR "ldmxcsr"
  56 #endif
  57
  58 static __always_inline void
  59 libc_feholdexcept_sse (fenv_t *e)
  60 {
  61   unsigned int mxcsr;
  62   asm (STMXCSR " %0" : "=m" (*&mxcsr));
  63   e->__mxcsr = mxcsr;
  64   mxcsr = (mxcsr | 0x1f80) & ~0x3f;
  65   asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
  66 }
  67
  68 static __always_inline void
  69 libc_feholdexcept_387 (fenv_t *e)
  70 {
  71   /* Recall that fnstenv has a side-effect of masking exceptions.
  72      Clobber all of the fp registers so that the TOS field is 0.  */
  73   asm volatile ("fnstenv %0; fnclex"
  74                 : "=m"(*e)
  75                 : : "st", "st(1)", "st(2)", "st(3)",
  76                     "st(4)", "st(5)", "st(6)", "st(7)");
  77 }
  78
  79 static __always_inline void
  80 libc_feholdexcept_setround_sse (fenv_t *e, int r)
  81 {
  82   unsigned int mxcsr;
  83   asm (STMXCSR " %0" : "=m" (*&mxcsr));
  84   e->__mxcsr = mxcsr;
  85   mxcsr = ((mxcsr | 0x1f80) & ~0x603f) | (r << 3);
  86   asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
  87 }
  88
  89 /* Set both rounding mode and precision.  A convenience function for use
  90    by libc_feholdexcept_setround and libc_feholdexcept_setround_53bit. */
  91 static __always_inline void
  92 libc_feholdexcept_setround_387_prec (fenv_t *e, int r)
  93 {
  94   libc_feholdexcept_387 (e);
  95
  96   fpu_control_t cw = e->__control_word;
  97   cw &= ~(_FPU_RC_ZERO | _FPU_EXTENDED);
  98   cw |= r | 0x3f;
  99   _FPU_SETCW (cw);
 100 }
 101
 102 static __always_inline void
 103 libc_feholdexcept_setround_387 (fenv_t *e, int r)
 104 {
 105   libc_feholdexcept_setround_387_prec (e, r | _FPU_EXTENDED);
 106 }
 107
 108 static __always_inline void
 109 libc_feholdexcept_setround_387_53bit (fenv_t *e, int r)
 110 {
 111   libc_feholdexcept_setround_387_prec (e, r | _FPU_DOUBLE);
 112 }
 113
 114 static __always_inline int
 115 libc_fetestexcept_sse (int e)
 116 {
 117   unsigned int mxcsr;
 118   asm volatile (STMXCSR " %0" : "=m" (*&mxcsr));
 119   return mxcsr & e & FE_ALL_EXCEPT;
 120 }
 121
 122 static __always_inline int
 123 libc_fetestexcept_387 (int ex)
 124 {
 125   fexcept_t temp;
 126   asm volatile ("fnstsw %0" : "=a" (temp));
 127   return temp & ex & FE_ALL_EXCEPT;
 128 }
 129
 130 static __always_inline void
 131 libc_fesetenv_sse (fenv_t *e)
 132 {
 133   asm volatile (LDMXCSR " %0" : : "m" (e->__mxcsr));
 134 }
 135
 136 static __always_inline void
 137 libc_fesetenv_387 (fenv_t *e)
 138 {
 139   /* Clobber all fp registers so that the TOS value we saved earlier is
 140      compatible with the current state of the compiler.  */
 141   asm volatile ("fldenv %0"
 142                 : : "m" (*e)
 143                 : "st", "st(1)", "st(2)", "st(3)",
 144                   "st(4)", "st(5)", "st(6)", "st(7)");
 145 }
 146
 147 static __always_inline int
 148 libc_feupdateenv_test_sse (fenv_t *e, int ex)
 149 {
 150   unsigned int mxcsr, old_mxcsr, cur_ex;
 151   asm volatile (STMXCSR " %0" : "=m" (*&mxcsr));
 152   cur_ex = mxcsr & FE_ALL_EXCEPT;
 153
 154   /* Merge current exceptions with the old environment.  */
 155   old_mxcsr = e->__mxcsr;
 156   mxcsr = old_mxcsr | cur_ex;
 157   asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
 158
 159   /* Raise SIGFPE for any new exceptions since the hold.  Expect that
 160      the normal environment has all exceptions masked.  */
 161   if (__builtin_expect ((old_mxcsr >> 7) & cur_ex, 0))
 162     __feraiseexcept (cur_ex);
 163
 164   /* Test for exceptions raised since the hold.  */
 165   return cur_ex & ex;
 166 }
 167
 168 static __always_inline int
 169 libc_feupdateenv_test_387 (fenv_t *e, int ex)
 170 {
 171   fexcept_t cur_ex;
 172
 173   /* Save current exceptions.  */
 174   asm volatile ("fnstsw %0" : "=a" (cur_ex));
 175   cur_ex &= FE_ALL_EXCEPT;
 176
 177   /* Reload original environment.  */
 178   libc_fesetenv_387 (e);
 179
 180   /* Merge current exceptions.  */
 181   __feraiseexcept (cur_ex);
 182
 183   /* Test for exceptions raised since the hold.  */
 184   return cur_ex & ex;
 185 }
 186
 187 static __always_inline void
 188 libc_feupdateenv_sse (fenv_t *e)
 189 {
 190   libc_feupdateenv_test_sse (e, 0);
 191 }
 192
 193 static __always_inline void
 194 libc_feupdateenv_387 (fenv_t *e)
 195 {
 196   libc_feupdateenv_test_387 (e, 0);
 197 }
 198
 199 static __always_inline void
 200 libc_feholdsetround_sse (fenv_t *e, int r)
 201 {
 202   unsigned int mxcsr;
 203   asm (STMXCSR " %0" : "=m" (*&mxcsr));
 204   e->__mxcsr = mxcsr;
 205   mxcsr = (mxcsr & ~0x6000) | (r << 3);
 206   asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
 207 }
 208
 209 static __always_inline void
 210 libc_feholdsetround_387_prec (fenv_t *e, int r)
 211 {
 212   fpu_control_t cw;
 213
 214   _FPU_GETCW (cw);
 215   e->__control_word = cw;
 216   cw &= ~(_FPU_RC_ZERO | _FPU_EXTENDED);
 217   cw |= r;
 218   _FPU_SETCW (cw);
 219 }
 220
 221 static __always_inline void
 222 libc_feholdsetround_387 (fenv_t *e, int r)
 223 {
 224   libc_feholdsetround_387_prec (e, r | _FPU_EXTENDED);
 225 }
 226
 227 static __always_inline void
 228 libc_feholdsetround_387_53bit (fenv_t *e, int r)
 229 {
 230   libc_feholdsetround_387_prec (e, r | _FPU_DOUBLE);
 231 }
 232
 233 static __always_inline void
 234 libc_feresetround_sse (fenv_t *e)
 235 {
 236   unsigned int mxcsr;
 237   asm (STMXCSR " %0" : "=m" (*&mxcsr));
 238   mxcsr = (mxcsr & ~0x6000) | (e->__mxcsr & 0x6000);
 239   asm volatile (LDMXCSR " %0" : : "m" (*&mxcsr));
 240 }
 241
 242 static __always_inline void
 243 libc_feresetround_387 (fenv_t *e)
 244 {
 245   _FPU_SETCW (e->__control_word);
 246 }
 247
 248 #ifdef __SSE_MATH__
 249 # define libc_feholdexceptf             libc_feholdexcept_sse
 250 # define libc_feholdexcept_setroundf    libc_feholdexcept_setround_sse
 251 # define libc_fetestexceptf             libc_fetestexcept_sse
 252 # define libc_fesetenvf                 libc_fesetenv_sse
 253 # define libc_feupdateenv_testf         libc_feupdateenv_test_sse
 254 # define libc_feupdateenvf              libc_feupdateenv_sse
 255 # define libc_feholdsetroundf           libc_feholdsetround_sse
 256 # define libc_feresetroundf             libc_feresetround_sse
 257 #else
 258 # define libc_feholdexceptf             libc_feholdexcept_387
 259 # define libc_feholdexcept_setroundf    libc_feholdexcept_setround_387
 260 # define libc_fetestexceptf             libc_fetestexcept_387
 261 # define libc_fesetenvf                 libc_fesetenv_387
 262 # define libc_feupdateenv_testf         libc_feupdateenv_test_387
 263 # define libc_feupdateenvf              libc_feupdateenv_387
 264 # define libc_feholdsetroundf           libc_feholdsetround_387
 265 # define libc_feresetroundf             libc_feresetround_387
 266 #endif /* __SSE_MATH__ */
 267
 268 #ifdef __SSE2_MATH__
 269 # define libc_feholdexcept              libc_feholdexcept_sse
 270 # define libc_feholdexcept_setround     libc_feholdexcept_setround_sse
 271 # define libc_fetestexcept              libc_fetestexcept_sse
 272 # define libc_fesetenv                  libc_fesetenv_sse
 273 # define libc_feupdateenv_test          libc_feupdateenv_test_sse
 274 # define libc_feupdateenv               libc_feupdateenv_sse
 275 # define libc_feholdsetround            libc_feholdsetround_sse
 276 # define libc_feresetround              libc_feresetround_sse
 277 #else
 278 # define libc_feholdexcept              libc_feholdexcept_387
 279 # define libc_feholdexcept_setround     libc_feholdexcept_setround_387
 280 # define libc_fetestexcept              libc_fetestexcept_387
 281 # define libc_fesetenv                  libc_fesetenv_387
 282 # define libc_feupdateenv_test          libc_feupdateenv_test_387
 283 # define libc_feupdateenv               libc_feupdateenv_387
 284 # define libc_feholdsetround            libc_feholdsetround_387
 285 # define libc_feresetround              libc_feresetround_387
 286 #endif /* __SSE2_MATH__ */
 287
 288 #define libc_feholdexceptl              libc_feholdexcept_387
 289 #define libc_feholdexcept_setroundl     libc_feholdexcept_setround_387
 290 #define libc_fetestexceptl              libc_fetestexcept_387
 291 #define libc_fesetenvl                  libc_fesetenv_387
 292 #define libc_feupdateenv_testl          libc_feupdateenv_test_387
 293 #define libc_feupdateenvl               libc_feupdateenv_387
 294 #define libc_feholdsetroundl            libc_feholdsetround_387
 295 #define libc_feresetroundl              libc_feresetround_387
 296
 297 #ifndef __SSE2_MATH__
 298 # define libc_feholdexcept_setround_53bit libc_feholdexcept_setround_387_53bit
 299 # define libc_feholdsetround_53bit      libc_feholdsetround_387_53bit
 300 #endif
 301
 302 #undef __mxcsr
 303
 304 #endif /* FENV_PRIVATE_H */