1/* Copyright (C) 1997-2025 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   <https://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/* Define bits representing the exception.  We use the bit positions
 23   of the appropriate bits in the FPU control word.  */
 24enum
 25  {
 26    FE_INVALID =
 27#define FE_INVALID	0x01
 28      FE_INVALID,
 29    __FE_DENORM = 0x02,
 30    FE_DIVBYZERO =
 31#define FE_DIVBYZERO	0x04
 32      FE_DIVBYZERO,
 33    FE_OVERFLOW =
 34#define FE_OVERFLOW	0x08
 35      FE_OVERFLOW,
 36    FE_UNDERFLOW =
 37#define FE_UNDERFLOW	0x10
 38      FE_UNDERFLOW,
 39    FE_INEXACT =
 40#define FE_INEXACT	0x20
 41      FE_INEXACT
 42  };
 43
 44#define FE_ALL_EXCEPT \
 45	(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
 46
 47/* The ix87 FPU supports all of the four defined rounding modes.  We
 48   use again the bit positions in the FPU control word as the values
 49   for the appropriate macros.  */
 50enum
 51  {
 52    FE_TONEAREST =
 53#define FE_TONEAREST	0
 54      FE_TONEAREST,
 55    FE_DOWNWARD =
 56#define FE_DOWNWARD	0x400
 57      FE_DOWNWARD,
 58    FE_UPWARD =
 59#define FE_UPWARD	0x800
 60      FE_UPWARD,
 61    FE_TOWARDZERO =
 62#define FE_TOWARDZERO	0xc00
 63      FE_TOWARDZERO
 64  };
 65
 66
 67/* Type representing exception flags.  */
 68typedef unsigned short int fexcept_t;
 69
 70
 71/* Type representing floating-point environment.  This structure
 72   corresponds to the layout of the block written by the `fstenv'
 73   instruction and has additional fields for the contents of the MXCSR
 74   register as written by the `stmxcsr' instruction.  */
 75typedef struct
 76  {
 77    unsigned short int __control_word;
 78    unsigned short int __glibc_reserved1;
 79    unsigned short int __status_word;
 80    unsigned short int __glibc_reserved2;
 81    unsigned short int __tags;
 82    unsigned short int __glibc_reserved3;
 83    unsigned int __eip;
 84    unsigned short int __cs_selector;
 85    unsigned int __opcode:11;
 86    unsigned int __glibc_reserved4:5;
 87    unsigned int __data_offset;
 88    unsigned short int __data_selector;
 89    unsigned short int __glibc_reserved5;
 90#ifdef __x86_64__
 91    unsigned int __mxcsr;
 92#endif
 93  }
 94fenv_t;
 95
 96/* If the default argument is used we use this value.  */
 97#define FE_DFL_ENV	((const fenv_t *) -1)
 98
 99#ifdef __USE_GNU
100/* Floating-point environment where none of the exception is masked.  */
101# define FE_NOMASK_ENV	((const fenv_t *) -2)
102#endif
103
104#if __GLIBC_USE (IEC_60559_BFP_EXT_C23)
105/* Type representing floating-point control modes.  */
106typedef struct
107  {
108    unsigned short int __control_word;
109    unsigned short int __glibc_reserved;
110    unsigned int __mxcsr;
111  }
112femode_t;
113
114/* Default floating-point control modes.  */
115# define FE_DFL_MODE	((const femode_t *) -1L)
116#endif