xref: /freebsd/sys/amd64/include/floatingpoint.h (revision 6e393973f57e7b6f632b763cd588b79c84ab63d1)
1 /*-
2  * Copyright (c) 1993 Andrew Moore, Talke Studio
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	from: @(#) floatingpoint.h	1.0 (Berkeley) 9/23/93
34  *	$Id: floatingpoint.h,v 1.3 1993/10/16 14:39:18 rgrimes Exp $
35  */
36 
37 /*
38  *	IEEE floating point structure and function definitions
39  */
40 
41 #ifndef _FLOATINGPOINT_H_
42 #define _FLOATINGPOINT_H_
43 
44 #include <sys/cdefs.h>
45 #include <sys/ieeefp.h>
46 
47 #ifdef __GNUC__
48 
49 #ifdef __i386__
50 
51 #define fnstcw(addr)	__asm("fnstcw %0" : "=m" (*addr) : "0" (*addr))
52 #define fnstsw(addr)	__asm("fnstsw %0" : "=m" (*addr) : "0" (*addr))
53 #define fnstenv(addr)	__asm("fnstenv %0" : "=m" (*addr) : "0" (*addr))
54 #define fldenv(addr)	__asm("fldenv %0" : : "m" (*addr))
55 
56 
57 /*
58  * return the contents of a FP register
59  */
60 static __inline__ int
61 __fpgetreg(int _reg)
62 {
63 	unsigned short _mem;
64 
65 	switch(_reg) {
66 	default:
67 		fnstcw(&_mem);
68 		break;
69 	case FP_STKY_REG:
70 		fnstsw(&_mem);
71 		break;
72 	}
73 	return _mem;
74 }
75 
76 /*
77  * set a FP mode; return previous mode
78  */
79 static __inline__ int
80 __fpsetreg(int _m, int _reg, int _fld, int _off)
81 {
82 	unsigned _env[7];
83 	unsigned _p;
84 
85 	fnstenv(_env);
86 	_p =  (_env[_reg] & _fld) >> _off;
87 	_env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld);
88 	fldenv(_env);
89 	return _p;
90 }
91 
92 #endif /* __i386__ */
93 
94 #endif /* __GNUC__ */
95 
96 /*
97  * SysV/386 FP control interface
98  */
99 #define fpgetround()	((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF)
100 #define fpsetround(m)	__fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF)
101 #define fpgetprec()	((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF)
102 #define fpsetprec(m)	__fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF)
103 #define fpgetmask()	((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF)
104 #define fpsetmask(m)	__fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF)
105 #define fpgetsticky()	((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF)
106 #define fpresetsticky(m)	__fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF)
107 #define fpsetsticky(m)	fpresetsticky(m)
108 
109 #endif /* !_FLOATINGPOINT_H_ */
110