about summary refs log tree commit diff
path: root/sysdeps/i386/fpu/bits/fenv.h
blob: 01ae50c5d28bf4e1a0272a9f5577c6975665bf07 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
/* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef _FENV_H
# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
#endif


/* Define bits representing the exception.  We use the bit positions
   of the appropriate bits in the FPU control word.  */
enum
  {
    FE_INVALID = 0x01,
#define FE_INVALID	FE_INVALID
    __FE_DENORM = 0x02,
    FE_DIVBYZERO = 0x04,
#define FE_DIVBYZERO	FE_DIVBYZERO
    FE_OVERFLOW = 0x08,
#define FE_OVERFLOW	FE_OVERFLOW
    FE_UNDERFLOW = 0x10,
#define FE_UNDERFLOW	FE_UNDERFLOW
    FE_INEXACT = 0x20
#define FE_INEXACT	FE_INEXACT
  };

#define FE_ALL_EXCEPT \
	(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)

/* The ix87 FPU supports all of the four defined rounding modes.  We
   use again the bit positions in the FPU control word as the values
   for the appropriate macros.  */
enum
  {
    FE_TONEAREST = 0,
#define FE_TONEAREST	FE_TONEAREST
    FE_DOWNWARD = 0x400,
#define FE_DOWNWARD	FE_DOWNWARD
    FE_UPWARD = 0x800,
#define FE_UPWARD	FE_UPWARD
    FE_TOWARDZERO = 0xc00
#define FE_TOWARDZERO	FE_TOWARDZERO
  };


/* Type representing exception flags.  */
typedef unsigned short int fexcept_t;


/* Type representing floating-point environment.  This function corresponds
   to the layout of the block written by the `fstenv'.  */
typedef struct
  {
    unsigned short int __control_word;
    unsigned short int __unused1;
    unsigned short int __status_word;
    unsigned short int __unused2;
    unsigned short int __tags;
    unsigned short int __unused3;
    unsigned int __eip;
    unsigned short int __cs_selector;
    unsigned int __opcode:11;
    unsigned int __unused4:5;
    unsigned int __data_offset;
    unsigned short int __data_selector;
    unsigned short int __unused5;
  }
fenv_t;

/* If the default argument is used we use this value.  */
#define FE_DFL_ENV	((__const fenv_t *) -1)

#ifdef __USE_GNU
/* Floating-point environment where none of the exception is masked.  */
# define FE_NOMASK_ENV	((__const fenv_t *) -2)
#endif