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 <posix/fenv.h>
32#include <arch/x86_64/fpu.h>
33
34const fenv_t __fe_dfl_env = {
35	{ 0xffff0000 | __INITIAL_FPUCW__,
36	  0xffff0000,
37	  0xffffffff,
38	  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
39	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
40	},
41	__INITIAL_MXCSR__
42};
43
44int
45fesetexceptflag(const fexcept_t *flagp, int excepts)
46{
47	fenv_t env;
48
49	__fnstenv(&env.__x87);
50	env.__x87.__status &= ~excepts;
51	env.__x87.__status |= *flagp & excepts;
52	__fldenv(env.__x87);
53
54	__stmxcsr(&env.__mxcsr);
55	env.__mxcsr &= ~excepts;
56	env.__mxcsr |= *flagp & excepts;
57	__ldmxcsr(env.__mxcsr);
58
59	return (0);
60}
61
62int
63feraiseexcept(int excepts)
64{
65	fexcept_t ex = excepts;
66
67	fesetexceptflag(&ex, excepts);
68	__fwait();
69	return (0);
70}
71
72int
73fegetenv(fenv_t *envp)
74{
75
76	__fnstenv(&envp->__x87);
77	__stmxcsr(&envp->__mxcsr);
78	/*
79	 * fnstenv masks all exceptions, so we need to restore the
80	 * control word to avoid this side effect.
81	 */
82	__fldcw(envp->__x87.__control);
83	return (0);
84}
85
86int
87feholdexcept(fenv_t *envp)
88{
89	uint32_t mxcsr;
90
91	__stmxcsr(&mxcsr);
92	__fnstenv(&envp->__x87);
93	__fnclex();
94	envp->__mxcsr = mxcsr;
95	mxcsr &= ~FE_ALL_EXCEPT;
96	mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
97	__ldmxcsr(mxcsr);
98	return (0);
99}
100
101int
102feupdateenv(const fenv_t *envp)
103{
104	uint32_t mxcsr;
105	uint16_t status;
106
107	__fnstsw(&status);
108	__stmxcsr(&mxcsr);
109	fesetenv(envp);
110	feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
111	return (0);
112}
113
114int
115__feenableexcept(int mask)
116{
117	uint32_t mxcsr, omask;
118	uint16_t control;
119
120	mask &= FE_ALL_EXCEPT;
121	__fnstcw(&control);
122	__stmxcsr(&mxcsr);
123	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
124	control &= ~mask;
125	__fldcw(control);
126	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
127	__ldmxcsr(mxcsr);
128	return (omask);
129}
130
131int
132__fedisableexcept(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
148__weak_reference(__feenableexcept, feenableexcept);
149__weak_reference(__fedisableexcept, fedisableexcept);
150