1/* $OpenBSD: fenv.h,v 1.3 2011/05/25 21:46:49 martynas Exp $ */ 2/* $NetBSD: fenv.h,v 1.1.6.2 2010/10/24 22:48:02 jym 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 _I386_FENV_H_ 31#define _I386_FENV_H_ 32 33/* 34 * Each symbol representing a floating point exception expands to an integer 35 * constant expression with values, such that bitwise-inclusive ORs of _all 36 * combinations_ of the constants result in distinct values. 37 * 38 * We use such values that allow direct bitwise operations on FPU/SSE registers. 39 */ 40#define FE_INVALID 0x01 41#define FE_DENORMAL 0x02 42#define FE_DIVBYZERO 0x04 43#define FE_OVERFLOW 0x08 44#define FE_UNDERFLOW 0x10 45#define FE_INEXACT 0x20 46 47/* 48 * The following symbol is simply the bitwise-inclusive OR of all floating-point 49 * exception constants defined above. 50 */ 51#define FE_ALL_EXCEPT (FE_INVALID | FE_DENORMAL | FE_DIVBYZERO | \ 52 FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT) 53#define _SSE_MASK_SHIFT 7 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 * The following symbol is simply the bitwise-inclusive OR of all floating-point 68 * rounding direction constants defined above. 69 */ 70#define _X87_ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | \ 71 FE_TOWARDZERO) 72#define _SSE_ROUND_SHIFT 3 73 74/* 75 * fenv_t represents the entire floating-point environment. 76 */ 77typedef struct { 78 struct { 79 unsigned int __control; /* Control word register */ 80 unsigned int __status; /* Status word register */ 81 unsigned int __tag; /* Tag word register */ 82 unsigned int __others[4]; /* EIP, Pointer Selector, etc */ 83 } __x87; 84 unsigned int __mxcsr; /* Control, status register */ 85} fenv_t; 86 87/* 88 * The following constant represents the default floating-point environment 89 * (that is, the one installed at program startup) and has type pointer to 90 * const-qualified fenv_t. 91 * 92 * It can be used as an argument to the functions within the <fenv.h> header 93 * that manage the floating-point environment, namely fesetenv() and 94 * feupdateenv(). 95 */ 96__BEGIN_DECLS 97extern fenv_t __fe_dfl_env; 98__END_DECLS 99#define FE_DFL_ENV ((const fenv_t *)&__fe_dfl_env) 100 101/* 102 * fexcept_t represents the floating-point status flags collectively, including 103 * any status the implementation associates with the flags. 104 * 105 * A floating-point status flag is a system variable whose value is set (but 106 * never cleared) when a floating-point exception is raised, which occurs as a 107 * side effect of exceptional floating-point arithmetic to provide auxiliary 108 * information. 109 * 110 * A floating-point control mode is a system variable whose value may be set by 111 * the user to affect the subsequent behavior of floating-point arithmetic. 112 */ 113typedef unsigned int fexcept_t; 114 115#endif /* !_I386_FENV_H_ */ 116