1 /* $OpenBSD: fenv.h,v 1.3 2019/03/12 22:14:50 patrick Exp $ */ 2 3 /* 4 * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef _MACHINE_FENV_H_ 20 #define _MACHINE_FENV_H_ 21 22 /* 23 * Each symbol representing a floating point exception expands to an integer 24 * constant expression with values, such that bitwise-inclusive ORs of _all 25 * combinations_ of the constants result in distinct values. 26 * 27 * We use such values that allow direct bitwise operations on FPU registers. 28 */ 29 #define FE_INVALID 0x01 30 #define FE_DIVBYZERO 0x02 31 #define FE_OVERFLOW 0x04 32 #define FE_UNDERFLOW 0x08 33 #define FE_INEXACT 0x10 34 #define FE_DENORMAL 0x80 35 36 /* 37 * The following symbol is simply the bitwise-inclusive OR of all floating-point 38 * exception constants defined above. 39 */ 40 #define FE_ALL_EXCEPT (FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | \ 41 FE_UNDERFLOW | FE_INEXACT | FE_DENORMAL) 42 43 /* 44 * Each symbol representing the rounding direction, expands to an integer 45 * constant expression whose value is distinct non-negative value. 46 * 47 * We use such values that allow direct bitwise operations on FPU registers. 48 */ 49 #define FE_TONEAREST 0x0 50 #define FE_UPWARD 0x1 51 #define FE_DOWNWARD 0x2 52 #define FE_TOWARDZERO 0x3 53 54 /* 55 * The following symbol is simply the bitwise-inclusive OR of all floating-point 56 * rounding direction constants defined above. 57 */ 58 #define _ROUND_MASK (FE_TONEAREST | FE_UPWARD | FE_DOWNWARD | \ 59 FE_TOWARDZERO) 60 #define _ROUND_SHIFT 22 61 62 /* 63 * fenv_t represents the entire floating-point environment. 64 */ 65 typedef unsigned long long fenv_t; 66 67 /* 68 * The following constant represents the default floating-point environment 69 * (that is, the one installed at program startup) and has type pointer to 70 * const-qualified fenv_t. 71 * 72 * It can be used as an argument to the functions within the <fenv.h> header 73 * that manage the floating-point environment, namely fesetenv() and 74 * feupdateenv(). 75 */ 76 __BEGIN_DECLS 77 extern fenv_t __fe_dfl_env; 78 __END_DECLS 79 #define FE_DFL_ENV ((const fenv_t *)&__fe_dfl_env) 80 81 /* 82 * fexcept_t represents the floating-point status flags collectively, including 83 * any status the implementation associates with the flags. 84 * 85 * A floating-point status flag is a system variable whose value is set (but 86 * never cleared) when a floating-point exception is raised, which occurs as a 87 * side effect of exceptional floating-point arithmetic to provide auxiliary 88 * information. 89 * 90 * A floating-point control mode is a system variable whose value may be set by 91 * the user to affect the subsequent behavior of floating-point arithmetic. 92 */ 93 typedef unsigned long long fexcept_t; 94 95 #endif /* !_MACHINE_FENV_H_ */ 96