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      1 /* Copyright (C) 1997,1998,1999,2000,2001,2004 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, write to the Free
     16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     17    02111-1307 USA.  */
     18 
     19 #ifndef _FENV_H
     20 # error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
     21 #endif
     22 
     23 #include <bits/wordsize.h>
     24 
     25 
     26 /* Define bits representing the exception.  We use the bit positions
     27    of the appropriate bits in the FPU control word.  */
     28 enum
     29   {
     30     FE_INVALID = 0x01,
     31 #define FE_INVALID	FE_INVALID
     32     __FE_DENORM = 0x02,
     33     FE_DIVBYZERO = 0x04,
     34 #define FE_DIVBYZERO	FE_DIVBYZERO
     35     FE_OVERFLOW = 0x08,
     36 #define FE_OVERFLOW	FE_OVERFLOW
     37     FE_UNDERFLOW = 0x10,
     38 #define FE_UNDERFLOW	FE_UNDERFLOW
     39     FE_INEXACT = 0x20
     40 #define FE_INEXACT	FE_INEXACT
     41   };
     42 
     43 #define FE_ALL_EXCEPT \
     44 	(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
     45 
     46 /* The ix87 FPU supports all of the four defined rounding modes.  We
     47    use again the bit positions in the FPU control word as the values
     48    for the appropriate macros.  */
     49 enum
     50   {
     51     FE_TONEAREST = 0,
     52 #define FE_TONEAREST	FE_TONEAREST
     53     FE_DOWNWARD = 0x400,
     54 #define FE_DOWNWARD	FE_DOWNWARD
     55     FE_UPWARD = 0x800,
     56 #define FE_UPWARD	FE_UPWARD
     57     FE_TOWARDZERO = 0xc00
     58 #define FE_TOWARDZERO	FE_TOWARDZERO
     59   };
     60 
     61 
     62 /* Type representing exception flags.  */
     63 typedef unsigned short int fexcept_t;
     64 
     65 
     66 /* Type representing floating-point environment.  This structure
     67    corresponds to the layout of the block written by the `fstenv'
     68    instruction and has additional fields for the contents of the MXCSR
     69    register as written by the `stmxcsr' instruction.  */
     70 typedef struct
     71   {
     72     unsigned short int __control_word;
     73     unsigned short int __unused1;
     74     unsigned short int __status_word;
     75     unsigned short int __unused2;
     76     unsigned short int __tags;
     77     unsigned short int __unused3;
     78     unsigned int __eip;
     79     unsigned short int __cs_selector;
     80     unsigned int __opcode:11;
     81     unsigned int __unused4:5;
     82     unsigned int __data_offset;
     83     unsigned short int __data_selector;
     84     unsigned short int __unused5;
     85 #if __WORDSIZE == 64
     86     unsigned int __mxcsr;
     87 #endif
     88   }
     89 fenv_t;
     90 
     91 /* If the default argument is used we use this value.  */
     92 #define FE_DFL_ENV	((__const fenv_t *) -1)
     93 
     94 #ifdef __USE_GNU
     95 /* Floating-point environment where none of the exception is masked.  */
     96 # define FE_NOMASK_ENV	((__const fenv_t *) -2)
     97 #endif
     98