Home | History | Annotate | Download | only in bits
      1 /*-
      2  * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG>
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     24  * SUCH DAMAGE.
     25  */
     26 
     27 #ifndef _BITS_FENV_X86_64_H_
     28 #define _BITS_FENV_X86_64_H_
     29 
     30 #include <sys/types.h>
     31 
     32 __BEGIN_DECLS
     33 
     34 /*
     35  * Each symbol representing a floating point exception expands to an integer
     36  * constant expression with values, such that bitwise-inclusive ORs of _all
     37  * combinations_ of the constants result in distinct values.
     38  *
     39  * We use such values that allow direct bitwise operations on FPU/SSE registers.
     40  */
     41 #define FE_INVALID    0x01
     42 #define FE_DENORMAL   0x02
     43 #define FE_DIVBYZERO  0x04
     44 #define FE_OVERFLOW   0x08
     45 #define FE_UNDERFLOW  0x10
     46 #define FE_INEXACT    0x20
     47 
     48 /*
     49  * The following symbol is simply the bitwise-inclusive OR of all floating-point
     50  * exception constants defined above.
     51  */
     52 #define FE_ALL_EXCEPT   (FE_INVALID | FE_DENORMAL | FE_DIVBYZERO | \
     53                          FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
     54 
     55 /*
     56  * Each symbol representing the rounding direction, expands to an integer
     57  * constant expression whose value is distinct non-negative value.
     58  *
     59  * We use such values that allow direct bitwise operations on FPU/SSE registers.
     60  */
     61 #define FE_TONEAREST  0x000
     62 #define FE_DOWNWARD   0x400
     63 #define FE_UPWARD     0x800
     64 #define FE_TOWARDZERO 0xc00
     65 
     66 /*
     67  * fenv_t represents the entire floating-point environment.
     68  */
     69 typedef struct {
     70   struct {
     71     __uint32_t __control;   /* Control word register */
     72     __uint32_t __status;    /* Status word register */
     73     __uint32_t __tag;       /* Tag word register */
     74     __uint32_t __others[4]; /* EIP, Pointer Selector, etc */
     75   } __x87;
     76   __uint32_t __mxcsr;       /* Control, status register */
     77 } fenv_t;
     78 
     79 /*
     80  * fexcept_t represents the floating-point status flags collectively, including
     81  * any status the implementation associates with the flags.
     82  *
     83  * A floating-point status flag is a system variable whose value is set (but
     84  * never cleared) when a floating-point exception is raised, which occurs as a
     85  * side effect of exceptional floating-point arithmetic to provide auxiliary
     86  * information.
     87  *
     88  * A floating-point control mode is a system variable whose value may be set by
     89  * the user to affect the subsequent behavior of floating-point arithmetic.
     90  */
     91 typedef __uint32_t fexcept_t;
     92 
     93 __END_DECLS
     94 
     95 #endif
     96