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 #pragma once
28 
29 #include <sys/types.h>
30 
31 __BEGIN_DECLS
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 
54 /*
55  * Each symbol representing the rounding direction, expands to an integer
56  * constant expression whose value is distinct non-negative value.
57  *
58  * We use such values that allow direct bitwise operations on FPU/SSE registers.
59  */
60 #define FE_TONEAREST  0x000
61 #define FE_DOWNWARD   0x400
62 #define FE_UPWARD     0x800
63 #define FE_TOWARDZERO 0xc00
64 
65 /*
66  * fenv_t represents the entire floating-point environment.
67  */
68 typedef struct {
69   struct {
70     __uint32_t __control;   /* Control word register */
71     __uint32_t __status;    /* Status word register */
72     __uint32_t __tag;       /* Tag word register */
73     __uint32_t __others[4]; /* EIP, Pointer Selector, etc */
74   } __x87;
75   __uint32_t __mxcsr;       /* Control, status register */
76 } fenv_t;
77 
78 /*
79  * fexcept_t represents the floating-point status flags collectively, including
80  * any status the implementation associates with the flags.
81  *
82  * A floating-point status flag is a system variable whose value is set (but
83  * never cleared) when a floating-point exception is raised, which occurs as a
84  * side effect of exceptional floating-point arithmetic to provide auxiliary
85  * information.
86  *
87  * A floating-point control mode is a system variable whose value may be set by
88  * the user to affect the subsequent behavior of floating-point arithmetic.
89  */
90 typedef __uint32_t fexcept_t;
91 
92 __END_DECLS
93