contrib/openbsd_libm/include/amd64/fenv.h

   1 /*      $OpenBSD: fenv.h,v 1.4 2011/05/25 21:46:49 martynas Exp $       */
   2 /*      $NetBSD: fenv.h,v 1.1 2010/07/31 21:47:54 joerg Exp $   */
   3
   4 /*-
   5  * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #ifndef _AMD64_FENV_H_
  31 #define _AMD64_FENV_H_
  32
  33 #include <sys/cdefs.h>
  34
  35 /*
  36  * Each symbol representing a floating point exception expands to an integer
  37  * constant expression with values, such that bitwise-inclusive ORs of _all
  38  * combinations_ of the constants result in distinct values.
  39  *
  40  * We use such values that allow direct bitwise operations on FPU/SSE registers.
  41  */
  42 #define FE_INVALID              0x01
  43 #define FE_DENORMAL             0x02
  44 #define FE_DIVBYZERO            0x04
  45 #define FE_OVERFLOW             0x08
  46 #define FE_UNDERFLOW            0x10
  47 #define FE_INEXACT              0x20
  48
  49 /*
  50  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  51  * exception constants defined above.
  52  */
  53 #define FE_ALL_EXCEPT           (FE_INVALID | FE_DENORMAL | FE_DIVBYZERO | \
  54                                  FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
  55 #define _SSE_MASK_SHIFT         7
  56
  57 /*
  58  * Each symbol representing the rounding direction, expands to an integer
  59  * constant expression whose value is distinct non-negative value.
  60  *
  61  * We use such values that allow direct bitwise operations on FPU/SSE registers.
  62  */
  63 #define FE_TONEAREST            0x000
  64 #define FE_DOWNWARD             0x400
  65 #define FE_UPWARD               0x800
  66 #define FE_TOWARDZERO           0xc00
  67
  68 /*
  69  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  70  * rounding direction constants defined above.
  71  */
  72 #define _X87_ROUND_MASK         (FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | \
  73                                  FE_TOWARDZERO)
  74 #define _SSE_ROUND_SHIFT        3
  75
  76 /*
  77  * fenv_t represents the entire floating-point environment.
  78  */
  79 typedef struct {
  80         struct {
  81                 unsigned int __control;         /* Control word register */
  82                 unsigned int __status;          /* Status word register */
  83                 unsigned int __tag;             /* Tag word register */
  84                 unsigned int __others[4];       /* EIP, Pointer Selector, etc */
  85         } __x87;
  86         unsigned int __mxcsr;                   /* Control, status register */
  87 } fenv_t;
  88
  89 /*
  90  * The following constant represents the default floating-point environment
  91  * (that is, the one installed at program startup) and has type pointer to
  92  * const-qualified fenv_t.
  93  *
  94  * It can be used as an argument to the functions within the <fenv.h> header
  95  * that manage the floating-point environment, namely fesetenv() and
  96  * feupdateenv().
  97  */
  98 __BEGIN_DECLS
  99 extern  fenv_t                  __fe_dfl_env;
 100 __END_DECLS
 101 #define FE_DFL_ENV              ((const fenv_t *)&__fe_dfl_env)
 102
 103 /*
 104  * fexcept_t represents the floating-point status flags collectively, including
 105  * any status the implementation associates with the flags.
 106  *
 107  * A floating-point status flag is a system variable whose value is set (but
 108  * never cleared) when a floating-point exception is raised, which occurs as a
 109  * side effect of exceptional floating-point arithmetic to provide auxiliary
 110  * information.
 111  *
 112  * A floating-point control mode is a system variable whose value may be set by
 113  * the user to affect the subsequent behavior of floating-point arithmetic.
 114  */
 115 typedef unsigned int            fexcept_t;
 116
 117 #endif  /* !_AMD64_FENV_H_ */