1  /* Copyright (C) 2000-2023 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.  */
      24  enum
      25    {
      26      FE_INVALID =
      27  #define FE_INVALID	0x80
      28        FE_INVALID,
      29      FE_DIVBYZERO =
      30  #define FE_DIVBYZERO	0x40
      31        FE_DIVBYZERO,
      32      FE_OVERFLOW =
      33  #define FE_OVERFLOW	0x20
      34        FE_OVERFLOW,
      35      FE_UNDERFLOW =
      36  #define FE_UNDERFLOW	0x10
      37        FE_UNDERFLOW,
      38      FE_INEXACT =
      39  #define FE_INEXACT	0x08
      40        FE_INEXACT
      41    };
      42  /* We dont use the y bit of the DXC in the floating point control register
      43     as glibc has no FE encoding for fe inexact incremented
      44     or fe inexact truncated.
      45     We currently  use the flag bits in the fpc
      46     as these are sticky for feholdenv & feupdatenv as it is defined
      47     in the HP Manpages.  */
      48  
      49  
      50  #define FE_ALL_EXCEPT \
      51  	(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
      52  
      53  enum
      54    {
      55      FE_TONEAREST =
      56  #define FE_TONEAREST	0
      57        FE_TONEAREST,
      58      FE_DOWNWARD =
      59  #define FE_DOWNWARD	0x3
      60        FE_DOWNWARD,
      61      FE_UPWARD =
      62  #define FE_UPWARD	0x2
      63        FE_UPWARD,
      64      FE_TOWARDZERO =
      65  #define FE_TOWARDZERO	0x1
      66        FE_TOWARDZERO
      67    };
      68  
      69  
      70  /* Type representing exception flags.  */
      71  typedef unsigned int fexcept_t; /* size of fpc */
      72  
      73  
      74  /* Type representing floating-point environment.  This function corresponds
      75     to the layout of the block used by fegetenv and fesetenv.  */
      76  typedef struct
      77  {
      78    fexcept_t __fpc;
      79    void *__unused;
      80    /* The field __unused (formerly __ieee_instruction_pointer) is a relict from
      81       commit "Remove PTRACE_PEEKUSER" (87b9b50f0d4b92248905e95a06a13c513dc45e59)
      82       and isn't used anymore.  */
      83  } fenv_t;
      84  
      85  /* If the default argument is used we use this value.  */
      86  #define FE_DFL_ENV	((const fenv_t *) -1)
      87  
      88  #ifdef __USE_GNU
      89  /* Floating-point environment where none of the exceptions are masked.  */
      90  # define FE_NOMASK_ENV	((const fenv_t *) -2)
      91  #endif
      92  
      93  #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
      94  /* Type representing floating-point control modes.  */
      95  typedef unsigned int femode_t;
      96  
      97  /* Default floating-point control modes.  */
      98  # define FE_DFL_MODE	((const femode_t *) -1L)
      99  #endif