Merge branch 'vendor/CVS'
[dragonfly.git] / lib / libm / arch / x86_64 / fenv.c
CommitLineData
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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 *
6b038396 26 * $FreeBSD: src/lib/msun/amd64/fenv.c,v 1.5 2010/02/03 20:23:47 kib Exp $
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27 */
28
29#include <sys/cdefs.h>
30#include <sys/types.h>
31#include <machine/npx.h>
32#include "fenv.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{
6b038396 89 __uint32_t mxcsr;
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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{
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104 __uint32_t mxcsr;
105 __uint16_t status;
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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{
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117 __uint32_t mxcsr, omask;
118 __uint16_t control;
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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{
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134 __uint32_t mxcsr, omask;
135 __uint16_t control;
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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);