lib/fenv-except-state-get.c

   1 /* Functions for saving the floating-point exception status flags.
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8
   9    This file is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Based on glibc/sysdeps/<cpu>/{fgetexcptflg.c,fsetexcptflg.c}
  18    together with glibc/sysdeps/<cpu>/{fpu_control.h,fenv_private.h,fenv_libc.h}.  */
  19
  20 #include <config.h>
  21
  22 /* Specification.  */
  23 #include <fenv.h>
  24
  25 #include "fenv-private.h"
  26
  27 #if defined __GNUC__ || defined __clang__ || defined _MSC_VER
  28
  29 # if (defined __x86_64__ || defined _M_X64) || (defined __i386 || defined _M_IX86)
  30
  31 /* On most OSes, fexcept_t is binary-equivalent to an 'unsigned short'.
  32    On NetBSD, OpenBSD, Solaris, Cygwin, MSVC, Android/x86_64, Minix, fexcept_t
  33    is equivalent to an 'unsigned int'.
  34    A simple C cast does the necessary conversion.  */
  35
  36 int
  37 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
  38 {
  39   /* Just like fetestexcept.  */
  40 #  if defined _MSC_VER
  41
  42   unsigned int mxcsr;
  43   _FPU_GETSSECW (mxcsr);
  44   *saved_flags = x86hardware_to_exceptions (mxcsr) & FE_ALL_EXCEPT & exceptions;
  45
  46 #  else
  47
  48   unsigned short fstat;
  49   _FPU_GETSTAT (fstat);
  50
  51   unsigned int mxcsr = 0;
  52   if (CPU_HAS_SSE ())
  53     {
  54       /* Look at the flags in the SSE unit as well.  */
  55       _FPU_GETSSECW (mxcsr);
  56     }
  57
  58   *saved_flags = x86hardware_to_exceptions (fstat | mxcsr)
  59                  & FE_ALL_EXCEPT & exceptions;
  60 #  endif
  61
  62   return 0;
  63 }
  64
  65 # elif defined __aarch64__ /* arm64 */
  66
  67 /* On Linux, NetBSD, and Android, fexcept_t is binary-equivalent to
  68    an 'unsigned int'.
  69    On macOS, fexcept_t is binary-equivalent to an 'unsigned short'.
  70    On FreeBSD and OpenBSD, fexcept_t is binary-equivalent to an 'unsigned long'.
  71    A simple C cast does the necessary conversion.  */
  72
  73 int
  74 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
  75 {
  76   /* Just like fetestexcept.  */
  77   unsigned long fpsr;
  78   _FPU_GETFPSR (fpsr);
  79   *saved_flags = fpsr & FE_ALL_EXCEPT & exceptions;
  80   return 0;
  81 }
  82
  83 # elif defined __arm__
  84
  85 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
  86
  87 int
  88 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
  89 {
  90   /* Just like fetestexcept.  */
  91 #  ifdef __SOFTFP__
  92   return -1;
  93 #  else
  94   unsigned int fpscr;
  95   _FPU_GETCW (fpscr);
  96   *saved_flags = fpscr & FE_ALL_EXCEPT & exceptions;
  97   return 0;
  98 #  endif
  99 }
 100
 101 # elif defined __alpha
 102
 103 /* On all OSes except NetBSD and OpenBSD, fexcept_t is binary-equivalent to
 104    an 'unsigned long'.
 105    On NetBSD, it is equivalent to an 'unsigned short'.
 106    On OpenBSD, it is equivalent to an 'unsigned int'.
 107    A simple C cast does the necessary conversion.  */
 108
 109 int
 110 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 111 {
 112   /* Just like fetestexcept.  */
 113   unsigned long swcr = __ieee_get_fp_control ();
 114   *saved_flags = swcr & FE_ALL_EXCEPT & exceptions;
 115   return 0;
 116 }
 117
 118 # elif defined __hppa
 119
 120 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
 121
 122 int
 123 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 124 {
 125   /* Just like fetestexcept.  */
 126   union { unsigned long long fpreg; unsigned int halfreg[2]; } s;
 127   /* Get the current status word. */
 128   __asm__ __volatile__ ("fstd %%fr0,0(%1)" : "=m" (s.fpreg) : "r" (&s.fpreg) : "%r0");
 129   *saved_flags = (s.halfreg[0] >> 27) & FE_ALL_EXCEPT & exceptions;
 130   return 0;
 131 }
 132
 133 # elif defined __ia64__
 134
 135 /* On all OSes except NetBSD, fexcept_t is binary-equivalent to
 136    an 'unsigned long'.
 137    On NetBSD, it is equivalent to an 'unsigned short'.
 138    A simple C cast does the necessary conversion.  */
 139
 140 int
 141 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 142 {
 143   /* Just like fetestexcept.  */
 144   unsigned long fpsr;
 145   _FPU_GETCW (fpsr);
 146   *saved_flags = (fpsr >> 13) & FE_ALL_EXCEPT & exceptions;
 147   return 0;
 148 }
 149
 150 # elif defined __m68k__
 151
 152 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
 153
 154 int
 155 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 156 {
 157   /* Just like fetestexcept.  */
 158   unsigned int fpsr;
 159   _FPU_GETFPSR (fpsr);
 160   *saved_flags = fpsr & FE_ALL_EXCEPT & exceptions;
 161   return 0;
 162 }
 163
 164 # elif defined __mips__
 165
 166 /* On all OSes except NetBSD and OpenBSD, fexcept_t is binary-equivalent to
 167    an 'unsigned short'.
 168    On NetBSD and OpenBSD, it is equivalent to an 'unsigned int'.
 169    A simple C cast does the necessary conversion.  */
 170
 171 int
 172 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 173 {
 174   /* Just like fetestexcept.  */
 175   unsigned int fcsr;
 176   _FPU_GETCW (fcsr);
 177   *saved_flags = fcsr & FE_ALL_EXCEPT & exceptions;
 178   return 0;
 179 }
 180
 181 # elif defined __loongarch__
 182
 183 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
 184
 185 int
 186 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 187 {
 188   /* Just like fetestexcept.  */
 189   unsigned int fcsr;
 190   _FPU_GETCW (fcsr);
 191   *saved_flags = fcsr & FE_ALL_EXCEPT & exceptions;
 192   return 0;
 193 }
 194
 195 # elif defined __powerpc__
 196
 197 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
 198
 199 int
 200 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 201 {
 202   /* Just like fetestexcept.  */
 203   union { unsigned long long u; double f; } memenv;
 204   _FPU_GETCW_AS_DOUBLE (memenv.f);
 205   *saved_flags = memenv.u & FE_ALL_EXCEPT & exceptions;
 206   return 0;
 207 }
 208
 209 # elif defined __riscv
 210
 211 /* On all OSes except FreeBSD, fexcept_t is binary-equivalent to
 212    an 'unsigned int'.
 213    On FreeBSD, it is equivalent to an 'unsigned long'.
 214    A simple C cast does the necessary conversion.  */
 215
 216 int
 217 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 218 {
 219   /* Just like fetestexcept.  */
 220   unsigned int flags;
 221   __asm__ __volatile__ ("frflags %0" : "=r" (flags)); /* same as "csrr %0, fflags" */
 222   *saved_flags = flags & FE_ALL_EXCEPT & exceptions;
 223   return 0;
 224 }
 225
 226 # elif defined __s390__ || defined __s390x__
 227
 228 /* On all OSes, fexcept_t is binary-equivalent to an 'unsigned int'.  */
 229
 230 int
 231 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 232 {
 233   /* Just like fetestexcept.  */
 234   unsigned int fpc;
 235   _FPU_GETCW (fpc);
 236 #  if FE_INEXACT == 8 /* glibc compatible FE_* values */
 237   *saved_flags = ((fpc >> 16) | ((fpc & 0x00000300) == 0 ? fpc >> 8 : 0))
 238                  & FE_ALL_EXCEPT & exceptions;
 239 #  else /* musl libc compatible FE_* values */
 240   *saved_flags = (fpc | ((fpc & 0x00000300) == 0 ? fpc << 8 : 0))
 241                  & FE_ALL_EXCEPT & exceptions;
 242 #  endif
 243   return 0;
 244 }
 245
 246 # elif defined __sh__
 247
 248 /* On glibc, fexcept_t is binary-equivalent to an 'unsigned short'.
 249    On all other OSes, fexcept_t is binary-equivalent to an 'unsigned int'.
 250    A simple C cast does the necessary conversion.  */
 251
 252 int
 253 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 254 {
 255   /* Just like fetestexcept.  */
 256   unsigned int fpscr;
 257   _FPU_GETCW (fpscr);
 258   *saved_flags = fpscr & FE_ALL_EXCEPT & exceptions;
 259   return 0;
 260 }
 261
 262 # elif defined __sparc
 263
 264 /* On all OSes except Solaris, fexcept_t is binary-equivalent to an 'unsigned long'.
 265    On Solaris, fexcept_t is an 'int'.
 266    A simple C cast does the necessary conversion.  */
 267
 268 int
 269 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 270 {
 271   /* Just like fetestexcept.  */
 272   unsigned long fsr;
 273   _FPU_GETCW (fsr);
 274 #  if FE_INEXACT == 32 /* glibc compatible FE_* values */
 275   *saved_flags = fsr & FE_ALL_EXCEPT & exceptions;
 276 #  else /* Solaris compatible FE_* values */
 277   *saved_flags = (fsr >> 5) & FE_ALL_EXCEPT & exceptions;
 278 #  endif
 279   return 0;
 280 }
 281
 282 # else
 283
 284 #  if defined __GNUC__ || defined __clang__
 285 #   warning "Unknown CPU / architecture. Please report your platform and compiler to <bug-gnulib@gnu.org>."
 286 #  endif
 287 #  define NEED_FALLBACK 1
 288
 289 # endif
 290
 291 #else
 292
 293 /* The compiler does not support __asm__ statements or equivalent
 294    intrinsics.  */
 295
 296 # if HAVE_FPSETSTICKY
 297 /* FreeBSD ≥ 3.1, NetBSD ≥ 1.1, OpenBSD, IRIX, Solaris, Minix ≥ 3.2.  */
 298
 299 /* Get fpgetsticky, fpsetsticky.  */
 300 #  include <ieeefp.h>
 301 /* The type is called 'fp_except_t' on FreeBSD, but 'fp_except' on
 302    all other systems.  */
 303 #  if !defined __FreeBSD__
 304 #   define fp_except_t fp_except
 305 #  endif
 306
 307 int
 308 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 309 {
 310   /* Just like fetestexcept.  */
 311   fp_except_t flags = fpgetsticky ();
 312   *saved_flags = flags & FE_ALL_EXCEPT & exceptions;
 313   return 0;
 314 }
 315
 316 # elif defined _AIX && defined __powerpc__ /* AIX */
 317
 318 #  include <float.h>
 319 #  include <fpxcp.h>
 320
 321 /* Documentation:
 322    <https://www.ibm.com/docs/en/aix/7.3?topic=f-fp-clr-flag-fp-set-flag-fp-read-flag-fp-swap-flag-subroutine>  */
 323
 324 int
 325 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 326 {
 327   /* Just like fetestexcept.  */
 328   fpflag_t flags = fp_read_flag ();
 329   *saved_flags = fpflag_to_exceptions (flags) & FE_ALL_EXCEPT & exceptions;
 330   return 0;
 331 }
 332
 333 # else
 334
 335 #  define NEED_FALLBACK 1
 336
 337 # endif
 338
 339 #endif
 340
 341 #if NEED_FALLBACK
 342
 343 /* A dummy fallback.  */
 344
 345 int
 346 fegetexceptflag (fexcept_t *saved_flags, int exceptions)
 347 {
 348   /* Just like fetestexcept.  */
 349   *saved_flags = 0;
 350   return 0;
 351 }
 352
 353 #endif