1 /* $NetBSD: fenv.h,v 1.3 2014/02/12 23:04:43 dsl Exp $ */ 2 /*- 3 * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #ifndef _AMD64_FENV_H_ 29 #define _AMD64_FENV_H_ 30 31 #ifndef _KERNEL 32 #include <sys/stdint.h> 33 #endif 34 35 /* Default x87 control word. */ 36 #define __INITIAL_NPXCW__ 0x037f 37 /* Modern NetBSD uses the default control word.. */ 38 #define __NetBSD_NPXCW__ __INITIAL_NPXCW__ 39 /* NetBSD before 6.99.26 forced IEEE double precision. */ 40 #define __NetBSD_COMPAT_NPXCW__ 0x127f 41 42 /* Default values for the mxcsr. All traps masked. */ 43 #define __INITIAL_MXCSR__ 0x1f80 44 45 #ifndef _KERNEL 46 /* 47 * Each symbol representing a floating point exception expands to an integer 48 * constant expression with values, such that bitwise-inclusive ORs of _all 49 * combinations_ of the constants result in distinct values. 50 * 51 * We use such values that allow direct bitwise operations on FPU/SSE registers. 52 */ 53 #define FE_INVALID 0x01 /* 000000000001 */ 54 #define FE_DENORMAL 0x02 /* 000000000010 */ 55 #define FE_DIVBYZERO 0x04 /* 000000000100 */ 56 #define FE_OVERFLOW 0x08 /* 000000001000 */ 57 #define FE_UNDERFLOW 0x10 /* 000000010000 */ 58 #define FE_INEXACT 0x20 /* 000000100000 */ 59 60 /* 61 * The following symbol is simply the bitwise-inclusive OR of all floating-point 62 * exception constants defined above 63 */ 64 #define FE_ALL_EXCEPT \ 65 (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 66 67 /* 68 * Each symbol representing the rounding direction, expands to an integer 69 * constant expression whose value is distinct non-negative value. 70 * 71 * We use such values that allow direct bitwise operations on FPU/SSE registers. 72 */ 73 #define FE_TONEAREST 0x000 /* 000000000000 */ 74 #define FE_DOWNWARD 0x400 /* 010000000000 */ 75 #define FE_UPWARD 0x800 /* 100000000000 */ 76 #define FE_TOWARDZERO 0xC00 /* 110000000000 */ 77 78 /* 79 * As compared to the x87 control word, the SSE unit's control word 80 * has the rounding control bits offset by 3 and the exception mask 81 * bits offset by 7. 82 */ 83 #define _X87_ROUNDING_MASK 0xC00 /* 110000000000 */ 84 #define _SSE_ROUNDING_MASK (0xC00 << 3) 85 #define _SSE_ROUND_SHIFT 3 86 #define _SSE_EMASK_SHIFT 7 87 88 /* 89 * fenv_t represents the entire floating-point environment 90 */ 91 typedef struct { 92 struct { 93 uint32_t control; /* Control word register */ 94 uint32_t status; /* Status word register */ 95 uint32_t tag; /* Tag word register */ 96 uint32_t others[4]; /* EIP, Pointer Selector, etc */ 97 } x87; 98 99 uint32_t mxcsr; /* Control and status register */ 100 } fenv_t; 101 102 extern fenv_t __fe_dfl_env; 103 #define FE_DFL_ENV ((const fenv_t *) &__fe_dfl_env) 104 105 /* 106 * fexcept_t represents the floating-point status flags collectively, including 107 * any status the implementation associates with the flags. 108 * 109 * A floating-point status flag is a system variable whose value is set (but 110 * never cleared) when a floating-point exception is raised, which occurs as a 111 * side effect of exceptional floating-point arithmetic to provide auxiliary 112 * information. 113 * 114 * A floating-point control mode is a system variable whose value may be set by 115 * the user to affect the subsequent behavior of floating-point arithmetic. 116 */ 117 typedef uint32_t fexcept_t; 118 #endif 119 120 #endif /* ! _AMD64_FENV_H_ */ 121