1/*-
2 * Copyright (c) 2004-2005 David Schultz <das@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 * $FreeBSD$
27 */
28
29#include <sys/cdefs.h>
30#include <sys/types.h>
31#include <machine/fpu.h>
32
33#define	__fenv_static
34#include "fenv.h"
35
36#ifdef __GNUC_GNU_INLINE__
37#error "This file must be compiled with C99 'inline' semantics"
38#endif
39
40const fenv_t __fe_dfl_env = {
41	{ 0xffff0000 | __INITIAL_FPUCW__,
42	  0xffff0000,
43	  0xffffffff,
44	  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
45	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
46	},
47	__INITIAL_MXCSR__
48};
49
50extern inline int feclearexcept(int __excepts);
51extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
52
53int
54fesetexceptflag(const fexcept_t *flagp, int excepts)
55{
56	fenv_t env;
57
58	__fnstenv(&env.__x87);
59	env.__x87.__status &= ~excepts;
60	env.__x87.__status |= *flagp & excepts;
61	__fldenv(env.__x87);
62
63	__stmxcsr(&env.__mxcsr);
64	env.__mxcsr &= ~excepts;
65	env.__mxcsr |= *flagp & excepts;
66	__ldmxcsr(env.__mxcsr);
67
68	return (0);
69}
70
71int
72feraiseexcept(int excepts)
73{
74	fexcept_t ex = excepts;
75
76	fesetexceptflag(&ex, excepts);
77	__fwait();
78	return (0);
79}
80
81extern inline int fetestexcept(int __excepts);
82extern inline int fegetround(void);
83extern inline int fesetround(int __round);
84
85int
86fegetenv(fenv_t *envp)
87{
88
89	__fnstenv(&envp->__x87);
90	__stmxcsr(&envp->__mxcsr);
91	/*
92	 * fnstenv masks all exceptions, so we need to restore the
93	 * control word to avoid this side effect.
94	 */
95	__fldcw(envp->__x87.__control);
96	return (0);
97}
98
99int
100feholdexcept(fenv_t *envp)
101{
102	__uint32_t mxcsr;
103
104	__stmxcsr(&mxcsr);
105	__fnstenv(&envp->__x87);
106	__fnclex();
107	envp->__mxcsr = mxcsr;
108	mxcsr &= ~FE_ALL_EXCEPT;
109	mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
110	__ldmxcsr(mxcsr);
111	return (0);
112}
113
114extern inline int fesetenv(const fenv_t *__envp);
115
116int
117feupdateenv(const fenv_t *envp)
118{
119	__uint32_t mxcsr;
120	__uint16_t status;
121
122	__fnstsw(&status);
123	__stmxcsr(&mxcsr);
124	fesetenv(envp);
125	feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
126	return (0);
127}
128
129int
130__feenableexcept(int mask)
131{
132	__uint32_t mxcsr, omask;
133	__uint16_t control;
134
135	mask &= FE_ALL_EXCEPT;
136	__fnstcw(&control);
137	__stmxcsr(&mxcsr);
138	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
139	control &= ~mask;
140	__fldcw(control);
141	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
142	__ldmxcsr(mxcsr);
143	return (omask);
144}
145
146int
147__fedisableexcept(int mask)
148{
149	__uint32_t mxcsr, omask;
150	__uint16_t control;
151
152	mask &= FE_ALL_EXCEPT;
153	__fnstcw(&control);
154	__stmxcsr(&mxcsr);
155	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
156	control |= mask;
157	__fldcw(control);
158	mxcsr |= mask << _SSE_EMASK_SHIFT;
159	__ldmxcsr(mxcsr);
160	return (omask);
161}
162
163__weak_reference(__feenableexcept, feenableexcept);
164__weak_reference(__fedisableexcept, fedisableexcept);
165