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