2 * Copyright (c) 1993 Andrew Moore, Talke Studio
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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9 * notice, this list of conditions and the following disclaimer.
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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.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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33 * from: @(#) floatingpoint.h 1.0 (Berkeley) 9/23/93
34 * $FreeBSD: src/sys/i386/include/floatingpoint.h,v 1.10.2.1 2002/06/30 00:55:09 bde Exp $
35 * $DragonFly: src/sys/cpu/i386/include/floatingpoint.h,v 1.2 2003/06/17 04:28:35 dillon Exp $
38 #ifndef _FLOATINGPOINT_H_
39 #define _FLOATINGPOINT_H_
42 * IEEE floating point structure and function definitions
46 * XXX the following undocumented pollution is exported:
48 * FP*FLD, FP*OFF and FP*REG from <machine/ieeefp.h>
51 #include <sys/cdefs.h>
52 #include <machine/ieeefp.h>
56 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
57 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
58 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
59 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
62 * return the contents of a FP register
70 * This is more efficient than it looks. The switch gets optimized
71 * away if _reg is constant.
73 * The default case only supports _reg == 0. We could handle more
74 * registers (e.g., tags) using fnstenv, but the interface doesn't
89 * set a FP mode; return previous mode
92 __fpsetreg(int _m, int _reg, int _fld, int _off)
98 * _reg == 0 could be handled better using fnstcw/fldcw.
101 _p = (_env[_reg] & _fld) >> _off;
102 _env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld);
107 #endif /* __GNUC__ */
110 * SysV/386 FP control interface
112 #define fpgetround() ((fp_rnd_t) \
113 ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF))
114 #define fpsetround(m) ((fp_rnd_t) \
115 __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF))
116 #define fpgetprec() ((fp_prec_t) \
117 ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF))
118 #define fpsetprec(m) ((fp_prec_t) \
119 __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF))
120 #define fpgetmask() ((fp_except_t) \
121 ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF))
122 #define fpsetmask(m) ((fp_except_t) \
123 (~__fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF)) & \
124 (FP_MSKS_FLD >> FP_MSKS_OFF))
125 #define fpgetsticky() ((fp_except_t) \
126 ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF))
127 #define fpresetsticky(m) ((fp_except_t) \
128 __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF))
129 #define fpsetsticky(m) fpresetsticky(m)
131 #endif /* !_FLOATINGPOINT_H_ */