• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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