math/math-svid-compat.h

   1 /* Declarations for SVID math error handling compatibility.
   2    Copyright (C) 1991-2021 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 #ifndef _MATH_SVID_COMPAT_H
  20 #define _MATH_SVID_COMPAT_H     1
  21
  22 /* Support for various different standard error handling behaviors.  */
  23 typedef enum
  24 {
  25   _IEEE_ = -1,  /* According to IEEE 754/IEEE 854.  */
  26   _SVID_,       /* According to System V, release 4.  */
  27   _XOPEN_,      /* Nowadays also Unix98.  */
  28   _POSIX_,
  29   _ISOC_        /* Actually this is ISO C99.  */
  30 } _LIB_VERSION_TYPE;
  31
  32 /* This variable can be changed at run-time to any of the values above to
  33    affect floating point error handling behavior (it may also be necessary
  34    to change the hardware FPU exception settings).  */
  35 extern _LIB_VERSION_TYPE _LIB_VERSION;
  36
  37 /* In SVID error handling, `matherr' is called with this description
  38    of the exceptional condition.  */
  39 struct exception
  40   {
  41     int type;
  42     char *name;
  43     double arg1;
  44     double arg2;
  45     double retval;
  46   };
  47
  48 extern int matherr (struct exception *__exc);
  49 extern int __matherr (struct exception *__exc);
  50
  51 #define X_TLOSS 1.41484755040568800000e+16
  52
  53 /* Types of exceptions in the `type' field.  */
  54 #define DOMAIN          1
  55 #define SING            2
  56 #define OVERFLOW        3
  57 #define UNDERFLOW       4
  58 #define TLOSS           5
  59 #define PLOSS           6
  60
  61 /* SVID mode specifies returning this large value instead of infinity.  */
  62 #define HUGE            3.40282347e+38F
  63
  64 /* The above definitions may be used in testcases.  The following code
  65    is only used in the implementation.  */
  66
  67 #ifdef _LIBC
  68 /* fdlibm kernel function */
  69 extern double __kernel_standard (double, double, int);
  70 extern float __kernel_standard_f (float, float, int);
  71 extern long double __kernel_standard_l (long double, long double, int);
  72
  73 # include <shlib-compat.h>
  74 # define LIBM_SVID_COMPAT SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_27)
  75 # if LIBM_SVID_COMPAT
  76 compat_symbol_reference (libm, matherr, matherr, GLIBC_2_0);
  77 compat_symbol_reference (libm, _LIB_VERSION, _LIB_VERSION, GLIBC_2_0);
  78 # else
  79 /* Except when building compat code, optimize out references to
  80    _LIB_VERSION and matherr.  */
  81 #  define _LIB_VERSION _POSIX_
  82 #  define matherr(EXC) ((void) (EXC), 0)
  83 # endif
  84 #endif
  85
  86 #endif /* math-svid-compat.h.  */