sysdeps/powerpc/fpu/fsetexcptflg.c

   1 /* Set floating-point environment exception handling.
   2    Copyright (C) 1997-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv_libc.h>
  20
  21 int
  22 __fesetexceptflag (const fexcept_t *flagp, int excepts)
  23 {
  24   fenv_union_t u, n;
  25   fexcept_t flag;
  26
  27   /* Get the current state.  */
  28   u.fenv = fegetenv_register ();
  29
  30   /* Ignore exceptions not listed in 'excepts'.  */
  31   flag = *flagp & excepts;
  32
  33   /* Replace the exception status */
  34   int excepts_mask = FPSCR_STICKY_BITS & excepts;
  35   if ((excepts & FE_INVALID) != 0)
  36     excepts_mask |= FE_ALL_INVALID;
  37   n.l = ((u.l & ~excepts_mask)
  38          | (flag & FPSCR_STICKY_BITS)
  39          /* Turn FE_INVALID into FE_INVALID_SOFTWARE.  */
  40          | (flag >> ((31 - FPSCR_VX) - (31 - FPSCR_VXSOFT))
  41             & FE_INVALID_SOFTWARE));
  42
  43   /* Store the new status word (along with the rest of the environment).
  44      This may cause floating-point exceptions if the restored state
  45      requests it.  */
  46   if (n.l != u.l)
  47     {
  48       if (n.l & fenv_exceptions_to_reg (excepts))
  49         /* Setting the exception flags may trigger a trap.  ISO C 23 § 7.6.4.4
  50             does not allow it.   */
  51         return -1;
  52
  53       fesetenv_register (n.fenv);
  54     }
  55
  56   /* Deal with FE_INVALID_SOFTWARE not being implemented on some chips.  */
  57   if (flag & FE_INVALID)
  58     feraiseexcept(FE_INVALID);
  59
  60   /* Success.  */
  61   return 0;
  62 }
  63
  64 #include <shlib-compat.h>
  65 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  66 strong_alias (__fesetexceptflag, __old_fesetexceptflag)
  67 compat_symbol (libm, __old_fesetexceptflag, fesetexceptflag, GLIBC_2_1);
  68 #endif
  69
  70 versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);