sysdeps/ia64/fpu/fraiseexcpt.c

   1 /* Raise given exceptions.
   2    Copyright (C) 1997-2024 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.h>
  20 #include <float.h>
  21 #include <math.h>
  22 #include <signal.h>
  23 #include <unistd.h>
  24
  25 int
  26 __feraiseexcept (int excepts)
  27 {
  28   double tmp;
  29   double dummy;
  30
  31   /* Raise exceptions represented by EXPECTS.  But we must raise only
  32      one signal at a time.  It is important the if the overflow/underflow
  33      exception and the inexact exception are given at the same time,
  34      the overflow/underflow exception precedes the inexact exception.  */
  35
  36   /* We do these bits in assembly to be certain GCC doesn't optimize
  37      away something important.  */
  38
  39   /* First: invalid exception.  */
  40   if (FE_INVALID & excepts)
  41     {
  42       /* One example of an invalid operation is 0 * Infinity.  */
  43       tmp = 0;
  44       __asm__ __volatile__ ("frcpa.s0 %0,p1=f0,f0" : "=f" (tmp) : : "p1" );
  45     }
  46
  47   /* Next: division by zero.  */
  48   if (FE_DIVBYZERO & excepts)
  49     __asm__ __volatile__ ("frcpa.s0 %0,p1=f1,f0" : "=f" (tmp) : : "p1" );
  50
  51   /* Next: overflow.  */
  52   if (FE_OVERFLOW & excepts)
  53     {
  54       dummy = DBL_MAX;
  55
  56       __asm__ __volatile__ ("fadd.d.s0 %0=%1,%1" : "=f" (dummy) : "0" (dummy));
  57     }
  58
  59   /* Next: underflow.  */
  60   if (FE_UNDERFLOW & excepts)
  61     {
  62       dummy = DBL_MIN;
  63
  64       __asm__ __volatile__ ("fnma.d.s0 %0=%1,%1,f0" : "=f" (tmp) : "f" (dummy));
  65   }
  66
  67   /* Last: inexact.  */
  68   if (FE_INEXACT & excepts)
  69     {
  70       dummy = DBL_MAX;
  71       __asm__ __volatile__ ("fsub.d.s0 %0=%1,f1" : "=f" (dummy) : "0" (dummy));
  72     }
  73
  74   /* Success.  */
  75   return 0;
  76 }
  77 libm_hidden_def (__feraiseexcept)
  78 weak_alias (__feraiseexcept, feraiseexcept)
  79 libm_hidden_weak (feraiseexcept)