1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <sys/cdefs.h>
32#include <sys/types.h>
33#include <machine/fpu.h>
34
35#define	__fenv_static
36#include "fenv.h"
37
38#ifdef __GNUC_GNU_INLINE__
39#error "This file must be compiled with C99 'inline' semantics"
40#endif
41
42const fenv_t __fe_dfl_env = {
43	{ 0xffff0000 | __INITIAL_FPUCW__,
44	  0xffff0000,
45	  0xffffffff,
46	  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
47	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
48	},
49	__INITIAL_MXCSR__
50};
51
52extern inline int feclearexcept(int __excepts);
53extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
54
55int
56fesetexceptflag(const fexcept_t *flagp, int excepts)
57{
58	fenv_t env;
59
60	__fnstenv(&env.__x87);
61	env.__x87.__status &= ~excepts;
62	env.__x87.__status |= *flagp & excepts;
63	__fldenv(&env.__x87);
64
65	__stmxcsr(&env.__mxcsr);
66	env.__mxcsr &= ~excepts;
67	env.__mxcsr |= *flagp & excepts;
68	__ldmxcsr(&env.__mxcsr);
69
70	return (0);
71}
72
73int
74feraiseexcept(int excepts)
75{
76	fexcept_t ex = excepts;
77
78	fesetexceptflag(&ex, excepts);
79	__fwait();
80	return (0);
81}
82
83extern inline int fetestexcept(int __excepts);
84extern inline int fegetround(void);
85extern inline int fesetround(int __round);
86
87int
88fegetenv(fenv_t *envp)
89{
90
91	__fnstenv(&envp->__x87);
92	__stmxcsr(&envp->__mxcsr);
93	/*
94	 * fnstenv masks all exceptions, so we need to restore the
95	 * control word to avoid this side effect.
96	 */
97	__fldcw(&envp->__x87.__control);
98	return (0);
99}
100
101int
102feholdexcept(fenv_t *envp)
103{
104	__uint32_t mxcsr;
105
106	__stmxcsr(&mxcsr);
107	__fnstenv(&envp->__x87);
108	__fnclex();
109	envp->__mxcsr = mxcsr;
110	mxcsr &= ~FE_ALL_EXCEPT;
111	mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
112	__ldmxcsr(&mxcsr);
113	return (0);
114}
115
116extern inline int fesetenv(const fenv_t *__envp);
117
118int
119feupdateenv(const fenv_t *envp)
120{
121	__uint32_t mxcsr;
122	__uint16_t status;
123
124	__fnstsw(&status);
125	__stmxcsr(&mxcsr);
126	fesetenv(envp);
127	feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
128	return (0);
129}
130
131int
132__feenableexcept(int mask)
133{
134	__uint32_t mxcsr, omask;
135	__uint16_t control;
136
137	mask &= FE_ALL_EXCEPT;
138	__fnstcw(&control);
139	__stmxcsr(&mxcsr);
140	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
141	control &= ~mask;
142	__fldcw(&control);
143	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
144	__ldmxcsr(&mxcsr);
145	return (omask);
146}
147
148int
149__fedisableexcept(int mask)
150{
151	__uint32_t mxcsr, omask;
152	__uint16_t control;
153
154	mask &= FE_ALL_EXCEPT;
155	__fnstcw(&control);
156	__stmxcsr(&mxcsr);
157	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
158	control |= mask;
159	__fldcw(&control);
160	mxcsr |= mask << _SSE_EMASK_SHIFT;
161	__ldmxcsr(&mxcsr);
162	return (omask);
163}
164
165__weak_reference(__feenableexcept, feenableexcept);
166__weak_reference(__fedisableexcept, fedisableexcept);
167