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
40 const 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
50 extern inline int feclearexcept(int __excepts);
51 extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
52
53 int
fesetexceptflag(const fexcept_t * flagp,int excepts)54 fesetexceptflag(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
71 int
feraiseexcept(int excepts)72 feraiseexcept(int excepts)
73 {
74 fexcept_t ex = excepts;
75
76 fesetexceptflag(&ex, excepts);
77 __fwait();
78 return (0);
79 }
80
81 extern inline int fetestexcept(int __excepts);
82 extern inline int fegetround(void);
83 extern inline int fesetround(int __round);
84
85 int
fegetenv(fenv_t * envp)86 fegetenv(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
99 int
feholdexcept(fenv_t * envp)100 feholdexcept(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
114 extern inline int fesetenv(const fenv_t *__envp);
115
116 int
feupdateenv(const fenv_t * envp)117 feupdateenv(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
129 int
__feenableexcept(int mask)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
146 int
__fedisableexcept(int mask)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