libc/sysdeps/linux/i386/bits/fenv.h

   1 /* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _FENV_H
  19 # error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
  20 #endif
  21
  22
  23 /* Define bits representing the exception.  We use the bit positions
  24    of the appropriate bits in the FPU control word.  */
  25 enum
  26   {
  27     FE_INVALID = 0x01,
  28 #define FE_INVALID      FE_INVALID
  29     __FE_DENORM = 0x02,
  30     FE_DIVBYZERO = 0x04,
  31 #define FE_DIVBYZERO    FE_DIVBYZERO
  32     FE_OVERFLOW = 0x08,
  33 #define FE_OVERFLOW     FE_OVERFLOW
  34     FE_UNDERFLOW = 0x10,
  35 #define FE_UNDERFLOW    FE_UNDERFLOW
  36     FE_INEXACT = 0x20
  37 #define FE_INEXACT      FE_INEXACT
  38   };
  39
  40 #define FE_ALL_EXCEPT \
  41         (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
  42
  43 /* The ix87 FPU supports all of the four defined rounding modes.  We
  44    use again the bit positions in the FPU control word as the values
  45    for the appropriate macros.  */
  46 enum
  47   {
  48     FE_TONEAREST = 0,
  49 #define FE_TONEAREST    FE_TONEAREST
  50     FE_DOWNWARD = 0x400,
  51 #define FE_DOWNWARD     FE_DOWNWARD
  52     FE_UPWARD = 0x800,
  53 #define FE_UPWARD       FE_UPWARD
  54     FE_TOWARDZERO = 0xc00
  55 #define FE_TOWARDZERO   FE_TOWARDZERO
  56   };
  57
  58
  59 /* Type representing exception flags.  */
  60 typedef unsigned short int fexcept_t;
  61
  62
  63 /* Type representing floating-point environment.  This function corresponds
  64    to the layout of the block written by the `fstenv'.  */
  65 typedef struct
  66   {
  67     unsigned short int __control_word;
  68     unsigned short int __uclibc_unused1;
  69     unsigned short int __status_word;
  70     unsigned short int __uclibc_unused2;
  71     unsigned short int __tags;
  72     unsigned short int __uclibc_unused3;
  73     unsigned int __eip;
  74     unsigned short int __cs_selector;
  75     unsigned int __opcode:11;
  76     unsigned int __uclibc_unused4:5;
  77     unsigned int __data_offset;
  78     unsigned short int __data_selector;
  79     unsigned short int __uclibc_unused5;
  80   }
  81 fenv_t;
  82
  83 /* If the default argument is used we use this value.  */
  84 #define FE_DFL_ENV      ((const fenv_t *) -1)
  85
  86 #ifdef __USE_GNU
  87 /* Floating-point environment where none of the exception is masked.  */
  88 # define FE_NOMASK_ENV  ((const fenv_t *) -2)
  89 #endif