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glibc  2.9
fraiseexcpt.c
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00001 /* Raise given exceptions.
00002    Copyright (C) 1997, 1999, 2000, 2002, 2007 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <fenv.h>
00021 #include <float.h>
00022 #include <math.h>
00023 #include <shlib-compat.h>
00024 
00025 int
00026 __feraiseexcept (int excepts)
00027 {
00028   static const struct {
00029     double zero, one, max, min, pi;
00030   } c = {
00031     0.0, 1.0, DBL_MAX, DBL_MIN, M_PI
00032   };
00033   double d;
00034 
00035   /* Raise exceptions represented by EXPECTS.  But we must raise only
00036      one signal at a time.  It is important the if the overflow/underflow
00037      exception and the inexact exception are given at the same time,
00038      the overflow/underflow exception follows the inexact exception.  */
00039 
00040   /* First: invalid exception.  */
00041   if ((FE_INVALID & excepts) != 0)
00042     {
00043       /* One example of a invalid operation is 0/0.  */
00044       __asm ("" : "=e" (d) : "0" (c.zero));
00045       d /= c.zero;
00046       __asm __volatile ("" : : "e" (d));
00047     }
00048 
00049   /* Next: division by zero.  */
00050   if ((FE_DIVBYZERO & excepts) != 0)
00051     {
00052       __asm ("" : "=e" (d) : "0" (c.one));
00053       d /= c.zero;
00054       __asm __volatile ("" : : "e" (d));
00055     }
00056 
00057   /* Next: overflow.  */
00058   if ((FE_OVERFLOW & excepts) != 0)
00059     {
00060       __asm ("" : "=e" (d) : "0" (c.max));
00061       d *= d;
00062       __asm __volatile ("" : : "e" (d));
00063     }
00064 
00065   /* Next: underflow.  */
00066   if ((FE_UNDERFLOW & excepts) != 0)
00067     {
00068       __asm ("" : "=e" (d) : "0" (c.min));
00069       d *= d;
00070       __asm __volatile ("" : : "e" (d));
00071     }
00072 
00073   /* Last: inexact.  */
00074   if ((FE_INEXACT & excepts) != 0)
00075     {
00076       __asm ("" : "=e" (d) : "0" (c.one));
00077       d /= c.pi;
00078       __asm __volatile ("" : : "e" (d));
00079     }
00080 
00081   /* Success.  */
00082   return 0;
00083 }
00084 
00085 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
00086 strong_alias (__feraiseexcept, __old_feraiseexcept)
00087 compat_symbol (libm, __old_feraiseexcept, feraiseexcept, GLIBC_2_1);
00088 #endif
00089 
00090 libm_hidden_ver (__feraiseexcept, feraiseexcept)
00091 versioned_symbol (libm, __feraiseexcept, feraiseexcept, GLIBC_2_2);