1 /*-
2 * Copyright (c) 2003 Peter Wemm.
3 * Copyright (c) 1990 Andrew Moore, Talke Studio
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
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.
21 *
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
32 * SUCH DAMAGE.
33 *
34 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93
35 * $FreeBSD$
36 */
37
38 #ifndef _MACHINE_IEEEFP_H_
39 #define _MACHINE_IEEEFP_H_
40
41 /*
42 * Deprecated historical FPU control interface
43 *
44 * IEEE floating point type, constant and function definitions.
45 * XXX: FP*FLD and FP*OFF are undocumented pollution.
46 */
47
48 #ifndef _SYS_CDEFS_H_
49 #error this file needs sys/cdefs.h as a prerequisite
50 #endif
51
52 /*
53 * Rounding modes.
54 */
55 typedef enum {
56 FP_RN=0, /* round to nearest */
57 FP_RM, /* round down towards minus infinity */
58 FP_RP, /* round up towards plus infinity */
59 FP_RZ /* truncate */
60 } fp_rnd_t;
61
62 /*
63 * Precision (i.e., rounding precision) modes.
64 */
65 typedef enum {
66 FP_PS=0, /* 24 bit (single-precision) */
67 FP_PRS, /* reserved */
68 FP_PD, /* 53 bit (double-precision) */
69 FP_PE /* 64 bit (extended-precision) */
70 } fp_prec_t;
71
72 #define fp_except_t int
73
74 /*
75 * Exception bit masks.
76 */
77 #define FP_X_INV 0x01 /* invalid operation */
78 #define FP_X_DNML 0x02 /* denormal */
79 #define FP_X_DZ 0x04 /* zero divide */
80 #define FP_X_OFL 0x08 /* overflow */
81 #define FP_X_UFL 0x10 /* underflow */
82 #define FP_X_IMP 0x20 /* (im)precision */
83 #define FP_X_STK 0x40 /* stack fault */
84
85 /*
86 * FPU control word bit-field masks.
87 */
88 #define FP_MSKS_FLD 0x3f /* exception masks field */
89 #define FP_PRC_FLD 0x300 /* precision control field */
90 #define FP_RND_FLD 0xc00 /* rounding control field */
91
92 /*
93 * FPU status word bit-field masks.
94 */
95 #define FP_STKY_FLD 0x3f /* sticky flags field */
96
97 /*
98 * FPU control word bit-field offsets (shift counts).
99 */
100 #define FP_MSKS_OFF 0 /* exception masks offset */
101 #define FP_PRC_OFF 8 /* precision control offset */
102 #define FP_RND_OFF 10 /* rounding control offset */
103
104 /*
105 * FPU status word bit-field offsets (shift counts).
106 */
107 #define FP_STKY_OFF 0 /* sticky flags offset */
108
109 #ifdef __GNUCLIKE_ASM
110
111 #define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr)))
112 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
113 #define __fnclex() __asm __volatile("fnclex")
114 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
115 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
116 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
117 #define __ldmxcsr(addr) __asm __volatile("ldmxcsr %0" : : "m" (*(addr)))
118 #define __stmxcsr(addr) __asm __volatile("stmxcsr %0" : "=m" (*(addr)))
119
120 /*
121 * Load the control word. Be careful not to trap if there is a currently
122 * unmasked exception (ones that will become freshly unmasked are not a
123 * problem). This case must be handled by a save/restore of the
124 * environment or even of the full x87 state. Accessing the environment
125 * is very inefficient, so only do it when necessary.
126 */
127 static __inline void
128 __fnldcw(unsigned short _cw, unsigned short _newcw)
129 {
130 struct {
131 unsigned _cw;
132 unsigned _other[6];
133 } _env;
134 unsigned short _sw;
135
136 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) {
137 __fnstsw(&_sw);
138 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) {
139 __fnstenv(&_env);
140 _env._cw = _newcw;
141 __fldenv(&_env);
142 return;
143 }
144 }
145 __fldcw(&_newcw);
146 }
147
148 static __inline fp_rnd_t
149 fpgetround(void)
150 {
151 unsigned short _cw;
152
153 __fnstcw(&_cw);
154 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF));
155 }
156
157 static __inline fp_rnd_t
158 fpsetround(fp_rnd_t _m)
159 {
160 fp_rnd_t _p;
161 unsigned short _cw, _newcw;
162
163 __fnstcw(&_cw);
164 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF);
165 _newcw = _cw & ~FP_RND_FLD;
166 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD;
167 __fnldcw(_cw, _newcw);
168 return (_p);
169 }
170
171 static __inline fp_prec_t
172 fpgetprec(void)
173 {
174 unsigned short _cw;
175
176 __fnstcw(&_cw);
177 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF));
178 }
179
180 static __inline fp_prec_t
181 fpsetprec(fp_prec_t _m)
182 {
183 fp_prec_t _p;
184 unsigned short _cw, _newcw;
185
186 __fnstcw(&_cw);
187 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF);
188 _newcw = _cw & ~FP_PRC_FLD;
189 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD;
190 __fnldcw(_cw, _newcw);
191 return (_p);
192 }
193
194 /*
195 * Get or set the exception mask.
196 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1
197 * means disable for x87 and SSE, but for fp*mask() it means enable.
198 */
199
200 static __inline fp_except_t
201 fpgetmask(void)
202 {
203 unsigned short _cw;
204
205 __fnstcw(&_cw);
206 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF);
207 }
208
209 static __inline fp_except_t
210 fpsetmask(fp_except_t _m)
211 {
212 fp_except_t _p;
213 unsigned short _cw, _newcw;
214
215 __fnstcw(&_cw);
216 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF;
217 _newcw = _cw & ~FP_MSKS_FLD;
218 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD;
219 __fnldcw(_cw, _newcw);
220 return (_p);
221 }
222
223 static __inline fp_except_t
224 fpgetsticky(void)
225 {
226 unsigned _ex;
227 unsigned short _sw;
228
229 __fnstsw(&_sw);
230 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF;
231 return ((fp_except_t)_ex);
232 }
233
234 static __inline fp_except_t
235 fpresetsticky(fp_except_t _m)
236 {
237 struct {
238 unsigned _cw;
239 unsigned _sw;
240 unsigned _other[5];
241 } _env;
242 fp_except_t _p;
243
244 _m &= FP_STKY_FLD >> FP_STKY_OFF;
245 _p = fpgetsticky();
246 if ((_p & ~_m) == _p)
247 return (_p);
248 if ((_p & ~_m) == 0) {
249 __fnclex();
250 return (_p);
251 }
252 __fnstenv(&_env);
253 _env._sw &= ~_m;
254 __fldenv(&_env);
255 return (_p);
256 }
257
258 #endif /* __GNUCLIKE_ASM */
259
260 #endif /* !_MACHINE_IEEEFP_H_ */
Cache object: 737f0c11a1669eb15e28bf6e3a3ffdef
|