xref: /openbsd-src/sys/lib/libkern/softfloat.h (revision 66ad965f4873a0970dea06fb53c307b8385e5a94)
1 /*	$OpenBSD: softfloat.h,v 1.2 2007/12/29 16:59:16 miod Exp $	*/
2 /*	$NetBSD: softfloat.h,v 1.1 2001/04/26 03:10:48 ross Exp $	*/
3 
4 /* This is a derivative work. */
5 
6 /*-
7  * Copyright (c) 2001 The NetBSD Foundation, Inc.
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to The NetBSD Foundation
11  * by Ross Harvey.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *        This product includes software developed by the NetBSD
24  *        Foundation, Inc. and its contributors.
25  * 4. Neither the name of The NetBSD Foundation nor the names of its
26  *    contributors may be used to endorse or promote products derived
27  *    from this software without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
30  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
31  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
32  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
33  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
34  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
35  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39  * POSSIBILITY OF SUCH DAMAGE.
40  */
41 
42 /*
43 ===============================================================================
44 
45 This C header file is part of the SoftFloat IEC/IEEE Floating-point
46 Arithmetic Package, Release 2a.
47 
48 Written by John R. Hauser.  This work was made possible in part by the
49 International Computer Science Institute, located at Suite 600, 1947 Center
50 Street, Berkeley, California 94704.  Funding was partially provided by the
51 National Science Foundation under grant MIP-9311980.  The original version
52 of this code was written as part of a project to build a fixed-point vector
53 processor in collaboration with the University of California at Berkeley,
54 overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
55 is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
56 arithmetic/SoftFloat.html'.
57 
58 THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable
59 effort has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT
60 WILL AT TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS
61 RESTRICTED TO PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL
62 RESPONSIBILITY FOR ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM
63 THEIR OWN USE OF THE SOFTWARE, AND WHO ALSO EFFECTIVELY INDEMNIFY
64 (possibly via similar legal warning) JOHN HAUSER AND THE INTERNATIONAL
65 COMPUTER SCIENCE INSTITUTE AGAINST ALL LOSSES, COSTS, OR OTHER PROBLEMS
66 ARISING FROM THE USE OF THE SOFTWARE BY THEIR CUSTOMERS AND CLIENTS.
67 
68 Derivative works are acceptable, even for commercial purposes, so long as
69 (1) they include prominent notice that the work is derivative, and (2) they
70 include prominent notice akin to these four paragraphs for those parts of
71 this code that are retained.
72 
73 ===============================================================================
74 */
75 
76 #include <sys/types.h>
77 
78 #if !defined(_KERNEL) && !defined(_STANDALONE)
79 #include <ieeefp.h>
80 #else
81 #include "machine/ieeefp.h"
82 #endif
83 #include <sys/endian.h>
84 
85 /*
86 -------------------------------------------------------------------------------
87 The macro `FLOATX80' must be defined to enable the extended double-precision
88 floating-point format `floatx80'.  If this macro is not defined, the
89 `floatx80' type will not be defined, and none of the functions that either
90 input or output the `floatx80' type will be defined.  The same applies to
91 the `FLOAT128' macro and the quadruple-precision format `float128'.
92 -------------------------------------------------------------------------------
93 */
94 /* #define FLOATX80 */
95 /* #define FLOAT128 */
96 
97 /*
98 -------------------------------------------------------------------------------
99 Software IEC/IEEE floating-point types.
100 -------------------------------------------------------------------------------
101 */
102 typedef u_int32_t float32;
103 typedef u_int64_t float64;
104 #ifdef FLOATX80
105 typedef struct {
106 #if BYTE_ORDER == BIG_ENDIAN
107     u_int16_t high;
108     u_int64_t low;
109 #else
110     u_int64_t low;
111     u_int16_t high;
112 #endif
113 } floatx80;
114 #endif
115 #ifdef FLOAT128
116 typedef struct {
117     u_int64_t high, low;
118 } float128;
119 #endif
120 
121 /*
122  * Some of the global variables that used to be here have been removed for
123  * fairly obvious (defopt-MULTIPROCESSOR) reasons.  The rest (which don't
124  * change dynamically) will be removed later. [ross]
125  */
126 
127 #define float_rounding_mode() fpgetround()
128 
129 /*
130 -------------------------------------------------------------------------------
131 Software IEC/IEEE floating-point underflow tininess-detection mode.
132 -------------------------------------------------------------------------------
133 */
134 
135 extern int float_detect_tininess;
136 enum {
137     float_tininess_after_rounding  = 1,
138     float_tininess_before_rounding = 0
139 };
140 
141 /*
142 -------------------------------------------------------------------------------
143 Software IEC/IEEE floating-point rounding mode.
144 -------------------------------------------------------------------------------
145 */
146 
147 enum {
148     float_round_nearest_even = FP_RN,
149     float_round_to_zero      = FP_RZ,
150     float_round_down         = FP_RM,
151     float_round_up           = FP_RP
152 };
153 
154 /*
155 -------------------------------------------------------------------------------
156 Software IEC/IEEE floating-point exception flags.
157 -------------------------------------------------------------------------------
158 */
159 
160 enum {
161     float_flag_inexact   =  FP_X_IMP,
162     float_flag_underflow =  FP_X_UFL,
163     float_flag_overflow  =  FP_X_OFL,
164     float_flag_divbyzero =  FP_X_DZ,
165     float_flag_invalid   =  FP_X_INV
166 };
167 
168 /*
169 -------------------------------------------------------------------------------
170 Software IEC/IEEE integer-to-floating-point conversion routines.
171 -------------------------------------------------------------------------------
172 */
173 float32 int32_to_float32( int );
174 float64 int32_to_float64( int );
175 #ifdef FLOATX80
176 floatx80 int32_to_floatx80( int );
177 #endif
178 #ifdef FLOAT128
179 float128 int32_to_float128( int );
180 #endif
181 #ifndef SOFTFLOAT_FOR_GCC /* __floatdi?f is in libgcc2.c */
182 float32 int64_to_float32( int64_t );
183 float64 int64_to_float64( int64_t );
184 #ifdef FLOATX80
185 floatx80 int64_to_floatx80( int64_t );
186 #endif
187 #ifdef FLOAT128
188 float128 int64_to_float128( int64_t );
189 #endif
190 #endif
191 
192 /*
193 -------------------------------------------------------------------------------
194 Software IEC/IEEE single-precision conversion routines.
195 -------------------------------------------------------------------------------
196 */
197 int float32_to_int32( float32 );
198 int float32_to_int32_round_to_zero( float32 );
199 #ifndef SOFTFLOAT_FOR_GCC /* __fix?fdi provided by libgcc2.c */
200 int64_t float32_to_int64( float32 );
201 int64_t float32_to_int64_round_to_zero( float32 );
202 #endif
203 float64 float32_to_float64( float32 );
204 #ifdef FLOATX80
205 floatx80 float32_to_floatx80( float32 );
206 #endif
207 #ifdef FLOAT128
208 float128 float32_to_float128( float32 );
209 #endif
210 
211 /*
212 -------------------------------------------------------------------------------
213 Software IEC/IEEE single-precision operations.
214 -------------------------------------------------------------------------------
215 */
216 float32 float32_round_to_int( float32 );
217 float32 float32_add( float32, float32 );
218 float32 float32_sub( float32, float32 );
219 float32 float32_mul( float32, float32 );
220 float32 float32_div( float32, float32 );
221 float32 float32_rem( float32, float32 );
222 float32 float32_sqrt( float32 );
223 int float32_eq( float32, float32 );
224 int float32_le( float32, float32 );
225 int float32_lt( float32, float32 );
226 int float32_eq_signaling( float32, float32 );
227 int float32_le_quiet( float32, float32 );
228 int float32_lt_quiet( float32, float32 );
229 #ifndef SOFTFLOAT_FOR_GCC
230 int float32_is_signaling_nan( float32 );
231 #endif
232 
233 /*
234 -------------------------------------------------------------------------------
235 Software IEC/IEEE double-precision conversion routines.
236 -------------------------------------------------------------------------------
237 */
238 int float64_to_int32( float64 );
239 int float64_to_int32_round_to_zero( float64 );
240 #ifndef SOFTFLOAT_FOR_GCC /* __fix?fdi provided by libgcc2.c */
241 int64_t float64_to_int64( float64 );
242 int64_t float64_to_int64_round_to_zero( float64 );
243 #endif
244 float32 float64_to_float32( float64 );
245 #ifdef FLOATX80
246 floatx80 float64_to_floatx80( float64 );
247 #endif
248 #ifdef FLOAT128
249 float128 float64_to_float128( float64 );
250 #endif
251 
252 /*
253 -------------------------------------------------------------------------------
254 Software IEC/IEEE double-precision operations.
255 -------------------------------------------------------------------------------
256 */
257 #define float64_default_nan 0xFFF8000000000000LL
258 
259 static __inline int
260 float64_is_nan(float64 a)
261 {
262 	return 0xFFE0000000000000LL < a << 1;
263 }
264 
265 static __inline int
266 float64_is_signaling_nan(float64 a)
267 {
268 	return (a >> 51 & 0xFFF) == 0xFFE && (a & 0x0007FFFFFFFFFFFFLL);
269 }
270 
271 float64 float64_round_to_int( float64 );
272 float64 float64_add( float64, float64 );
273 float64 float64_sub( float64, float64 );
274 float64 float64_mul( float64, float64 );
275 float64 float64_div( float64, float64 );
276 float64 float64_rem( float64, float64 );
277 float64 float64_sqrt( float64 );
278 int float64_eq( float64, float64 );
279 int float64_le( float64, float64 );
280 int float64_lt( float64, float64 );
281 int float64_eq_signaling( float64, float64 );
282 int float64_le_quiet( float64, float64 );
283 int float64_lt_quiet( float64, float64 );
284 #ifndef SOFTFLOAT_FOR_GCC
285 int float64_is_signaling_nan( float64 );
286 #endif
287 
288 #ifdef FLOATX80
289 
290 /*
291 -------------------------------------------------------------------------------
292 Software IEC/IEEE extended double-precision conversion routines.
293 -------------------------------------------------------------------------------
294 */
295 int floatx80_to_int32( floatx80 );
296 int floatx80_to_int32_round_to_zero( floatx80 );
297 int64_t floatx80_to_int64( floatx80 );
298 int64_t floatx80_to_int64_round_to_zero( floatx80 );
299 float32 floatx80_to_float32( floatx80 );
300 float64 floatx80_to_float64( floatx80 );
301 #ifdef FLOAT128
302 float128 floatx80_to_float128( floatx80 );
303 #endif
304 
305 /*
306 -------------------------------------------------------------------------------
307 Software IEC/IEEE extended double-precision rounding precision.  Valid
308 values are 32, 64, and 80.
309 -------------------------------------------------------------------------------
310 */
311 extern int floatx80_rounding_precision;
312 
313 /*
314 -------------------------------------------------------------------------------
315 Software IEC/IEEE extended double-precision operations.
316 -------------------------------------------------------------------------------
317 */
318 floatx80 floatx80_round_to_int( floatx80 );
319 floatx80 floatx80_add( floatx80, floatx80 );
320 floatx80 floatx80_sub( floatx80, floatx80 );
321 floatx80 floatx80_mul( floatx80, floatx80 );
322 floatx80 floatx80_div( floatx80, floatx80 );
323 floatx80 floatx80_rem( floatx80, floatx80 );
324 floatx80 floatx80_sqrt( floatx80 );
325 int floatx80_eq( floatx80, floatx80 );
326 int floatx80_le( floatx80, floatx80 );
327 int floatx80_lt( floatx80, floatx80 );
328 int floatx80_eq_signaling( floatx80, floatx80 );
329 int floatx80_le_quiet( floatx80, floatx80 );
330 int floatx80_lt_quiet( floatx80, floatx80 );
331 int floatx80_is_signaling_nan( floatx80 );
332 
333 #endif
334 
335 #ifdef FLOAT128
336 
337 /*
338 -------------------------------------------------------------------------------
339 Software IEC/IEEE quadruple-precision conversion routines.
340 -------------------------------------------------------------------------------
341 */
342 int float128_to_int32( float128 );
343 int float128_to_int32_round_to_zero( float128 );
344 int64_t float128_to_int64( float128 );
345 int64_t float128_to_int64_round_to_zero( float128 );
346 float32 float128_to_float32( float128 );
347 float64 float128_to_float64( float128 );
348 #ifdef FLOATX80
349 floatx80 float128_to_floatx80( float128 );
350 #endif
351 
352 /*
353 -------------------------------------------------------------------------------
354 Software IEC/IEEE quadruple-precision operations.
355 -------------------------------------------------------------------------------
356 */
357 float128 float128_round_to_int( float128 );
358 float128 float128_add( float128, float128 );
359 float128 float128_sub( float128, float128 );
360 float128 float128_mul( float128, float128 );
361 float128 float128_div( float128, float128 );
362 float128 float128_rem( float128, float128 );
363 float128 float128_sqrt( float128 );
364 int float128_eq( float128, float128 );
365 int float128_le( float128, float128 );
366 int float128_lt( float128, float128 );
367 int float128_eq_signaling( float128, float128 );
368 int float128_le_quiet( float128, float128 );
369 int float128_lt_quiet( float128, float128 );
370 int float128_is_signaling_nan( float128 );
371 
372 #endif
373