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: src/lib/msun/amd64/fenv.h,v 1.5 2005/03/16 22:34:14 das Exp $
27 */
28
29 #ifndef _FENV_H_
30 #define _FENV_H_
31
32 #include <sys/cdefs.h>
33 #include <sys/_types.h>
34
35 typedef struct {
36 struct {
37 __uint32_t __control;
38 __uint32_t __status;
39 __uint32_t __tag;
40 char __other[16];
41 } __x87;
42 __uint32_t __mxcsr;
43 } fenv_t;
44
45 typedef __uint16_t fexcept_t;
46
47 /* Exception flags */
48 #define FE_INVALID 0x01
49 #define FE_DENORMAL 0x02
50 #define FE_DIVBYZERO 0x04
51 #define FE_OVERFLOW 0x08
52 #define FE_UNDERFLOW 0x10
53 #define FE_INEXACT 0x20
54 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
55 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
56
57 /* Rounding modes */
58 #define FE_TONEAREST 0x0000
59 #define FE_DOWNWARD 0x0400
60 #define FE_UPWARD 0x0800
61 #define FE_TOWARDZERO 0x0c00
62 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
63 FE_UPWARD | FE_TOWARDZERO)
64
65 /*
66 * As compared to the x87 control word, the SSE unit's control word
67 * has the rounding control bits offset by 3 and the exception mask
68 * bits offset by 7.
69 */
70 #define _SSE_ROUND_SHIFT 3
71 #define _SSE_EMASK_SHIFT 7
72
73 __BEGIN_DECLS
74
75 /* Default floating-point environment */
76 extern const fenv_t __fe_dfl_env;
77 #define FE_DFL_ENV (&__fe_dfl_env)
78
79 #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw))
80 #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env))
81 #define __fnclex() __asm __volatile("fnclex")
82 #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env)))
83 #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
84 #define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
85 #define __fwait() __asm __volatile("fwait")
86 #define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr))
87 #define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
88
89 static __inline int
feclearexcept(int __excepts)90 feclearexcept(int __excepts)
91 {
92 fenv_t __env;
93
94 if (__excepts == FE_ALL_EXCEPT) {
95 __fnclex();
96 } else {
97 __fnstenv(&__env.__x87);
98 __env.__x87.__status &= ~__excepts;
99 __fldenv(__env.__x87);
100 }
101 __stmxcsr(&__env.__mxcsr);
102 __env.__mxcsr &= ~__excepts;
103 __ldmxcsr(__env.__mxcsr);
104 return (0);
105 }
106
107 static __inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)108 fegetexceptflag(fexcept_t *__flagp, int __excepts)
109 {
110 int __mxcsr, __status;
111
112 __stmxcsr(&__mxcsr);
113 __fnstsw(&__status);
114 *__flagp = (__mxcsr | __status) & __excepts;
115 return (0);
116 }
117
118 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
119 int feraiseexcept(int __excepts);
120
121 static __inline int
fetestexcept(int __excepts)122 fetestexcept(int __excepts)
123 {
124 int __mxcsr, __status;
125
126 __stmxcsr(&__mxcsr);
127 __fnstsw(&__status);
128 return ((__status | __mxcsr) & __excepts);
129 }
130
131 static __inline int
fegetround(void)132 fegetround(void)
133 {
134 int __control;
135
136 /*
137 * We assume that the x87 and the SSE unit agree on the
138 * rounding mode. Reading the control word on the x87 turns
139 * out to be about 5 times faster than reading it on the SSE
140 * unit on an Opteron 244.
141 */
142 __fnstcw(&__control);
143 return (__control & _ROUND_MASK);
144 }
145
146 static __inline int
fesetround(int __round)147 fesetround(int __round)
148 {
149 int __mxcsr, __control;
150
151 if (__round & ~_ROUND_MASK)
152 return (-1);
153
154 __fnstcw(&__control);
155 __control &= ~_ROUND_MASK;
156 __control |= __round;
157 __fldcw(__control);
158
159 __stmxcsr(&__mxcsr);
160 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
161 __mxcsr |= __round << _SSE_ROUND_SHIFT;
162 __ldmxcsr(__mxcsr);
163
164 return (0);
165 }
166
167 int fegetenv(fenv_t *__envp);
168 int feholdexcept(fenv_t *__envp);
169
170 static __inline int
fesetenv(const fenv_t * __envp)171 fesetenv(const fenv_t *__envp)
172 {
173
174 __fldenv(__envp->__x87);
175 __ldmxcsr(__envp->__mxcsr);
176 return (0);
177 }
178
179 int feupdateenv(const fenv_t *__envp);
180
181 #if __BSD_VISIBLE
182
183 int feenableexcept(int __mask);
184 int fedisableexcept(int __mask);
185
186 static __inline int
fegetexcept(void)187 fegetexcept(void)
188 {
189 int __control;
190
191 /*
192 * We assume that the masks for the x87 and the SSE unit are
193 * the same.
194 */
195 __fnstcw(&__control);
196 return (~__control & FE_ALL_EXCEPT);
197 }
198
199 #endif /* __BSD_VISIBLE */
200
201 __END_DECLS
202
203 #endif /* !_FENV_H_ */
204