2 * Copyright (c) 2003 Peter Wemm.
3 * Copyright (c) 1990 Andrew Moore, Talke Studio
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93
35 * $FreeBSD: src/sys/i386/include/ieeefp.h,v 1.14 2008/01/11 18:59:35 bde Exp $
38 #ifndef _CPU_IEEEFP_H_
39 #define _CPU_IEEEFP_H_
42 * IEEE floating point type, constant and function definitions.
43 * XXX: FP*FLD and FP*OFF are undocumented pollution.
50 FP_RN=0, /* round to nearest */
51 FP_RM, /* round down towards minus infinity */
52 FP_RP, /* round up towards plus infinity */
57 * Precision (i.e., rounding precision) modes.
60 FP_PS=0, /* 24 bit (single-precision) */
61 FP_PRS, /* reserved */
62 FP_PD, /* 53 bit (double-precision) */
63 FP_PE /* 64 bit (extended-precision) */
66 #define fp_except_t int
69 * Exception bit masks.
71 #define FP_X_INV 0x01 /* invalid operation */
72 #define FP_X_DNML 0x02 /* denormal */
73 #define FP_X_DZ 0x04 /* zero divide */
74 #define FP_X_OFL 0x08 /* overflow */
75 #define FP_X_UFL 0x10 /* underflow */
76 #define FP_X_IMP 0x20 /* (im)precision */
77 #define FP_X_STK 0x40 /* stack fault */
80 * FPU control word bit-field masks.
82 #define FP_MSKS_FLD 0x3f /* exception masks field */
83 #define FP_PRC_FLD 0x300 /* precision control field */
84 #define FP_RND_FLD 0xc00 /* rounding control field */
87 * FPU status word bit-field masks.
89 #define FP_STKY_FLD 0x3f /* sticky flags field */
92 * FPU control word bit-field offsets (shift counts).
94 #define FP_MSKS_OFF 0 /* exception masks offset */
95 #define FP_PRC_OFF 8 /* precision control offset */
96 #define FP_RND_OFF 10 /* rounding control offset */
99 * FPU status word bit-field offsets (shift counts).
101 #define FP_STKY_OFF 0 /* sticky flags offset */
105 #define _fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr)))
106 #define _fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
107 #define _fnclex() __asm __volatile("fnclex")
108 #define _fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
109 #define _fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
110 #define _fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
113 * Load the control word. Be careful not to trap if there is a currently
114 * unmasked exception (ones that will become freshly unmasked are not a
115 * problem). This case must be handled by a save/restore of the
116 * environment or even of the full x87 state. Accessing the environment
117 * is very inefficient, so only do it when necessary.
120 _fnldcw(unsigned short _cw, unsigned short _newcw)
128 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) {
130 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) {
140 static __inline fp_rnd_t
146 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF));
149 static __inline fp_rnd_t
150 fpsetround(fp_rnd_t _m)
153 unsigned short _cw, _newcw;
156 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF);
157 _newcw = _cw & ~FP_RND_FLD;
158 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD;
159 _fnldcw(_cw, _newcw);
163 static __inline fp_prec_t
169 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF));
172 static __inline fp_prec_t
173 fpsetprec(fp_prec_t _m)
176 unsigned short _cw, _newcw;
179 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF);
180 _newcw = _cw & ~FP_PRC_FLD;
181 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD;
182 _fnldcw(_cw, _newcw);
187 * Get or set the exception mask.
188 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1
189 * means disable for x87 and SSE, but for fp*mask() it means enable.
192 static __inline fp_except_t
198 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF);
201 static __inline fp_except_t
202 fpsetmask(fp_except_t _m)
205 unsigned short _cw, _newcw;
208 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF;
209 _newcw = _cw & ~FP_MSKS_FLD;
210 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD;
211 _fnldcw(_cw, _newcw);
215 static __inline fp_except_t
222 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF;
223 return ((fp_except_t)_ex);
226 static __inline fp_except_t
227 fpresetsticky(fp_except_t _m)
236 _m &= FP_STKY_FLD >> FP_STKY_OFF;
238 if ((_p & ~_m) == _p)
240 if ((_p & ~_m) == 0) {
250 #endif /* __GNUC__ */
252 /* Suppress prototypes in the MI header. */
253 #define _IEEEFP_INLINED_ 1
255 #endif /* !_CPU_IEEEFP_H_ */