xref: /netbsd-src/external/gpl3/gcc/dist/libgcc/soft-fp/extended.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Software floating-point emulation.
2    Definitions for IEEE Extended Precision.
3    Copyright (C) 1999-2015 Free Software Foundation, Inc.
4    This file is part of the GNU C Library.
5    Contributed by Jakub Jelinek (jj@ultra.linux.cz).
6 
7    The GNU C Library is free software; you can redistribute it and/or
8    modify it under the terms of the GNU Lesser General Public
9    License as published by the Free Software Foundation; either
10    version 2.1 of the License, or (at your option) any later version.
11 
12    In addition to the permissions in the GNU Lesser General Public
13    License, the Free Software Foundation gives you unlimited
14    permission to link the compiled version of this file into
15    combinations with other programs, and to distribute those
16    combinations without any restriction coming from the use of this
17    file.  (The Lesser General Public License restrictions do apply in
18    other respects; for example, they cover modification of the file,
19    and distribution when not linked into a combine executable.)
20 
21    The GNU C Library is distributed in the hope that it will be useful,
22    but WITHOUT ANY WARRANTY; without even the implied warranty of
23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24    Lesser General Public License for more details.
25 
26    You should have received a copy of the GNU Lesser General Public
27    License along with the GNU C Library; if not, see
28    <http://www.gnu.org/licenses/>.  */
29 
30 #ifndef SOFT_FP_EXTENDED_H
31 #define SOFT_FP_EXTENDED_H	1
32 
33 #if _FP_W_TYPE_SIZE < 32
34 # error "Here's a nickel, kid. Go buy yourself a real computer."
35 #endif
36 
37 #if _FP_W_TYPE_SIZE < 64
38 # define _FP_FRACTBITS_E	(4*_FP_W_TYPE_SIZE)
39 # define _FP_FRACTBITS_DW_E	(8*_FP_W_TYPE_SIZE)
40 #else
41 # define _FP_FRACTBITS_E	(2*_FP_W_TYPE_SIZE)
42 # define _FP_FRACTBITS_DW_E	(4*_FP_W_TYPE_SIZE)
43 #endif
44 
45 #define _FP_FRACBITS_E		64
46 #define _FP_FRACXBITS_E		(_FP_FRACTBITS_E - _FP_FRACBITS_E)
47 #define _FP_WFRACBITS_E		(_FP_WORKBITS + _FP_FRACBITS_E)
48 #define _FP_WFRACXBITS_E	(_FP_FRACTBITS_E - _FP_WFRACBITS_E)
49 #define _FP_EXPBITS_E		15
50 #define _FP_EXPBIAS_E		16383
51 #define _FP_EXPMAX_E		32767
52 
53 #define _FP_QNANBIT_E		\
54 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-2) % _FP_W_TYPE_SIZE)
55 #define _FP_QNANBIT_SH_E		\
56 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-2+_FP_WORKBITS) % _FP_W_TYPE_SIZE)
57 #define _FP_IMPLBIT_E		\
58 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-1) % _FP_W_TYPE_SIZE)
59 #define _FP_IMPLBIT_SH_E		\
60 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-1+_FP_WORKBITS) % _FP_W_TYPE_SIZE)
61 #define _FP_OVERFLOW_E		\
62 	((_FP_W_TYPE) 1 << (_FP_WFRACBITS_E % _FP_W_TYPE_SIZE))
63 
64 #define _FP_WFRACBITS_DW_E	(2 * _FP_WFRACBITS_E)
65 #define _FP_WFRACXBITS_DW_E	(_FP_FRACTBITS_DW_E - _FP_WFRACBITS_DW_E)
66 #define _FP_HIGHBIT_DW_E	\
67   ((_FP_W_TYPE) 1 << (_FP_WFRACBITS_DW_E - 1) % _FP_W_TYPE_SIZE)
68 
69 typedef float XFtype __attribute__ ((mode (XF)));
70 
71 #if _FP_W_TYPE_SIZE < 64
72 
73 union _FP_UNION_E
74 {
75   XFtype flt;
76   struct _FP_STRUCT_LAYOUT
77   {
78 # if __BYTE_ORDER == __BIG_ENDIAN
79     unsigned long pad1 : _FP_W_TYPE_SIZE;
80     unsigned long pad2 : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
81     unsigned long sign : 1;
82     unsigned long exp : _FP_EXPBITS_E;
83     unsigned long frac1 : _FP_W_TYPE_SIZE;
84     unsigned long frac0 : _FP_W_TYPE_SIZE;
85 # else
86     unsigned long frac0 : _FP_W_TYPE_SIZE;
87     unsigned long frac1 : _FP_W_TYPE_SIZE;
88     unsigned exp : _FP_EXPBITS_E;
89     unsigned sign : 1;
90 # endif /* not bigendian */
91   } bits __attribute__ ((packed));
92 };
93 
94 
95 # define FP_DECL_E(X)		_FP_DECL (4, X)
96 
97 # define FP_UNPACK_RAW_E(X, val)			\
98   do							\
99     {							\
100       union _FP_UNION_E FP_UNPACK_RAW_E_flo;		\
101       FP_UNPACK_RAW_E_flo.flt = (val);			\
102 							\
103       X##_f[2] = 0;					\
104       X##_f[3] = 0;					\
105       X##_f[0] = FP_UNPACK_RAW_E_flo.bits.frac0;	\
106       X##_f[1] = FP_UNPACK_RAW_E_flo.bits.frac1;	\
107       X##_e  = FP_UNPACK_RAW_E_flo.bits.exp;		\
108       X##_s  = FP_UNPACK_RAW_E_flo.bits.sign;		\
109     }							\
110   while (0)
111 
112 # define FP_UNPACK_RAW_EP(X, val)			\
113   do							\
114     {							\
115       union _FP_UNION_E *FP_UNPACK_RAW_EP_flo		\
116 	= (union _FP_UNION_E *) (val);			\
117 							\
118       X##_f[2] = 0;					\
119       X##_f[3] = 0;					\
120       X##_f[0] = FP_UNPACK_RAW_EP_flo->bits.frac0;	\
121       X##_f[1] = FP_UNPACK_RAW_EP_flo->bits.frac1;	\
122       X##_e  = FP_UNPACK_RAW_EP_flo->bits.exp;		\
123       X##_s  = FP_UNPACK_RAW_EP_flo->bits.sign;		\
124     }							\
125   while (0)
126 
127 # define FP_PACK_RAW_E(val, X)			\
128   do						\
129     {						\
130       union _FP_UNION_E FP_PACK_RAW_E_flo;	\
131 						\
132       if (X##_e)				\
133 	X##_f[1] |= _FP_IMPLBIT_E;		\
134       else					\
135 	X##_f[1] &= ~(_FP_IMPLBIT_E);		\
136       FP_PACK_RAW_E_flo.bits.frac0 = X##_f[0];	\
137       FP_PACK_RAW_E_flo.bits.frac1 = X##_f[1];	\
138       FP_PACK_RAW_E_flo.bits.exp   = X##_e;	\
139       FP_PACK_RAW_E_flo.bits.sign  = X##_s;	\
140 						\
141       (val) = FP_PACK_RAW_E_flo.flt;		\
142     }						\
143   while (0)
144 
145 # define FP_PACK_RAW_EP(val, X)				\
146   do							\
147     {							\
148       if (!FP_INHIBIT_RESULTS)				\
149 	{						\
150 	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
151 	    = (union _FP_UNION_E *) (val);		\
152 							\
153 	  if (X##_e)					\
154 	    X##_f[1] |= _FP_IMPLBIT_E;			\
155 	  else						\
156 	    X##_f[1] &= ~(_FP_IMPLBIT_E);		\
157 	  FP_PACK_RAW_EP_flo->bits.frac0 = X##_f[0];	\
158 	  FP_PACK_RAW_EP_flo->bits.frac1 = X##_f[1];	\
159 	  FP_PACK_RAW_EP_flo->bits.exp   = X##_e;	\
160 	  FP_PACK_RAW_EP_flo->bits.sign  = X##_s;	\
161 	}						\
162     }							\
163   while (0)
164 
165 # define FP_UNPACK_E(X, val)			\
166   do						\
167     {						\
168       FP_UNPACK_RAW_E (X, (val));		\
169       _FP_UNPACK_CANONICAL (E, 4, X);		\
170     }						\
171   while (0)
172 
173 # define FP_UNPACK_EP(X, val)			\
174   do						\
175     {						\
176       FP_UNPACK_RAW_EP (X, (val));		\
177       _FP_UNPACK_CANONICAL (E, 4, X);		\
178     }						\
179   while (0)
180 
181 # define FP_UNPACK_SEMIRAW_E(X, val)		\
182   do						\
183     {						\
184       FP_UNPACK_RAW_E (X, (val));		\
185       _FP_UNPACK_SEMIRAW (E, 4, X);		\
186     }						\
187   while (0)
188 
189 # define FP_UNPACK_SEMIRAW_EP(X, val)		\
190   do						\
191     {						\
192       FP_UNPACK_RAW_EP (X, (val));		\
193       _FP_UNPACK_SEMIRAW (E, 4, X);		\
194     }						\
195   while (0)
196 
197 # define FP_PACK_E(val, X)			\
198   do						\
199     {						\
200       _FP_PACK_CANONICAL (E, 4, X);		\
201       FP_PACK_RAW_E ((val), X);			\
202     }						\
203   while (0)
204 
205 # define FP_PACK_EP(val, X)			\
206   do						\
207     {						\
208       _FP_PACK_CANONICAL (E, 4, X);		\
209       FP_PACK_RAW_EP ((val), X);		\
210     }						\
211   while (0)
212 
213 # define FP_PACK_SEMIRAW_E(val, X)		\
214   do						\
215     {						\
216       _FP_PACK_SEMIRAW (E, 4, X);		\
217       FP_PACK_RAW_E ((val), X);			\
218     }						\
219   while (0)
220 
221 # define FP_PACK_SEMIRAW_EP(val, X)		\
222   do						\
223     {						\
224       _FP_PACK_SEMIRAW (E, 4, X);		\
225       FP_PACK_RAW_EP ((val), X);		\
226     }						\
227   while (0)
228 
229 # define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 4, X)
230 # define FP_NEG_E(R, X)		_FP_NEG (E, 4, R, X)
231 # define FP_ADD_E(R, X, Y)	_FP_ADD (E, 4, R, X, Y)
232 # define FP_SUB_E(R, X, Y)	_FP_SUB (E, 4, R, X, Y)
233 # define FP_MUL_E(R, X, Y)	_FP_MUL (E, 4, R, X, Y)
234 # define FP_DIV_E(R, X, Y)	_FP_DIV (E, 4, R, X, Y)
235 # define FP_SQRT_E(R, X)	_FP_SQRT (E, 4, R, X)
236 # define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 4, 8, R, X, Y, Z)
237 
238 /* Square root algorithms:
239    We have just one right now, maybe Newton approximation
240    should be added for those machines where division is fast.
241    This has special _E version because standard _4 square
242    root would not work (it has to start normally with the
243    second word and not the first), but as we have to do it
244    anyway, we optimize it by doing most of the calculations
245    in two UWtype registers instead of four.  */
246 
247 # define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
248   do							\
249     {							\
250       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
251       _FP_FRAC_SRL_4 (X, (_FP_WORKBITS));		\
252       while (q)						\
253 	{						\
254 	  T##_f[1] = S##_f[1] + (q);			\
255 	  if (T##_f[1] <= X##_f[1])			\
256 	    {						\
257 	      S##_f[1] = T##_f[1] + (q);		\
258 	      X##_f[1] -= T##_f[1];			\
259 	      R##_f[1] += (q);				\
260 	    }						\
261 	  _FP_FRAC_SLL_2 (X, 1);			\
262 	  (q) >>= 1;					\
263 	}						\
264       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
265       while (q)						\
266 	{						\
267 	  T##_f[0] = S##_f[0] + (q);			\
268 	  T##_f[1] = S##_f[1];				\
269 	  if (T##_f[1] < X##_f[1]			\
270 	      || (T##_f[1] == X##_f[1]			\
271 		  && T##_f[0] <= X##_f[0]))		\
272 	    {						\
273 	      S##_f[0] = T##_f[0] + (q);		\
274 	      S##_f[1] += (T##_f[0] > S##_f[0]);	\
275 	      _FP_FRAC_DEC_2 (X, T);			\
276 	      R##_f[0] += (q);				\
277 	    }						\
278 	  _FP_FRAC_SLL_2 (X, 1);			\
279 	  (q) >>= 1;					\
280 	}						\
281       _FP_FRAC_SLL_4 (R, (_FP_WORKBITS));		\
282       if (X##_f[0] | X##_f[1])				\
283 	{						\
284 	  if (S##_f[1] < X##_f[1]			\
285 	      || (S##_f[1] == X##_f[1]			\
286 		  && S##_f[0] < X##_f[0]))		\
287 	    R##_f[0] |= _FP_WORK_ROUND;			\
288 	  R##_f[0] |= _FP_WORK_STICKY;			\
289 	}						\
290     }							\
291   while (0)
292 
293 # define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 4, (r), X, Y, (un), (ex))
294 # define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 4, (r), X, Y, (ex))
295 # define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 4, (r), X, Y, (ex))
296 
297 # define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 4, (r), X, (rsz), (rsg))
298 # define FP_TO_INT_ROUND_E(r, X, rsz, rsg)	\
299   _FP_TO_INT_ROUND (E, 4, (r), X, (rsz), (rsg))
300 # define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 4, X, (r), (rs), rt)
301 
302 # define _FP_FRAC_HIGH_E(X)	(X##_f[2])
303 # define _FP_FRAC_HIGH_RAW_E(X)	(X##_f[1])
304 
305 # define _FP_FRAC_HIGH_DW_E(X)	(X##_f[4])
306 
307 #else   /* not _FP_W_TYPE_SIZE < 64 */
308 union _FP_UNION_E
309 {
310   XFtype flt;
311   struct _FP_STRUCT_LAYOUT
312   {
313 # if __BYTE_ORDER == __BIG_ENDIAN
314     _FP_W_TYPE pad  : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
315     unsigned sign   : 1;
316     unsigned exp    : _FP_EXPBITS_E;
317     _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
318 # else
319     _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
320     unsigned exp    : _FP_EXPBITS_E;
321     unsigned sign   : 1;
322 # endif
323   } bits;
324 };
325 
326 # define FP_DECL_E(X)		_FP_DECL (2, X)
327 
328 # define FP_UNPACK_RAW_E(X, val)		\
329   do						\
330     {						\
331       union _FP_UNION_E FP_UNPACK_RAW_E_flo;	\
332       FP_UNPACK_RAW_E_flo.flt = (val);		\
333 						\
334       X##_f0 = FP_UNPACK_RAW_E_flo.bits.frac;	\
335       X##_f1 = 0;				\
336       X##_e = FP_UNPACK_RAW_E_flo.bits.exp;	\
337       X##_s = FP_UNPACK_RAW_E_flo.bits.sign;	\
338     }						\
339   while (0)
340 
341 # define FP_UNPACK_RAW_EP(X, val)		\
342   do						\
343     {						\
344       union _FP_UNION_E *FP_UNPACK_RAW_EP_flo	\
345 	= (union _FP_UNION_E *) (val);		\
346 						\
347       X##_f0 = FP_UNPACK_RAW_EP_flo->bits.frac;	\
348       X##_f1 = 0;				\
349       X##_e = FP_UNPACK_RAW_EP_flo->bits.exp;	\
350       X##_s = FP_UNPACK_RAW_EP_flo->bits.sign;	\
351     }						\
352   while (0)
353 
354 # define FP_PACK_RAW_E(val, X)			\
355   do						\
356     {						\
357       union _FP_UNION_E FP_PACK_RAW_E_flo;	\
358 						\
359       if (X##_e)				\
360 	X##_f0 |= _FP_IMPLBIT_E;		\
361       else					\
362 	X##_f0 &= ~(_FP_IMPLBIT_E);		\
363       FP_PACK_RAW_E_flo.bits.frac = X##_f0;	\
364       FP_PACK_RAW_E_flo.bits.exp  = X##_e;	\
365       FP_PACK_RAW_E_flo.bits.sign = X##_s;	\
366 						\
367       (val) = FP_PACK_RAW_E_flo.flt;		\
368     }						\
369   while (0)
370 
371 # define FP_PACK_RAW_EP(fs, val, X)			\
372   do							\
373     {							\
374       if (!FP_INHIBIT_RESULTS)				\
375 	{						\
376 	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
377 	    = (union _FP_UNION_E *) (val);		\
378 							\
379 	  if (X##_e)					\
380 	    X##_f0 |= _FP_IMPLBIT_E;			\
381 	  else						\
382 	    X##_f0 &= ~(_FP_IMPLBIT_E);			\
383 	  FP_PACK_RAW_EP_flo->bits.frac = X##_f0;	\
384 	  FP_PACK_RAW_EP_flo->bits.exp  = X##_e;	\
385 	  FP_PACK_RAW_EP_flo->bits.sign = X##_s;	\
386 	}						\
387     }							\
388   while (0)
389 
390 
391 # define FP_UNPACK_E(X, val)			\
392   do						\
393     {						\
394       FP_UNPACK_RAW_E (X, (val));		\
395       _FP_UNPACK_CANONICAL (E, 2, X);		\
396     }						\
397   while (0)
398 
399 # define FP_UNPACK_EP(X, val)			\
400   do						\
401     {						\
402       FP_UNPACK_RAW_EP (X, (val));		\
403       _FP_UNPACK_CANONICAL (E, 2, X);		\
404     }						\
405   while (0)
406 
407 # define FP_UNPACK_SEMIRAW_E(X, val)		\
408   do						\
409     {						\
410       FP_UNPACK_RAW_E (X, (val));		\
411       _FP_UNPACK_SEMIRAW (E, 2, X);		\
412     }						\
413   while (0)
414 
415 # define FP_UNPACK_SEMIRAW_EP(X, val)		\
416   do						\
417     {						\
418       FP_UNPACK_RAW_EP (X, (val));		\
419       _FP_UNPACK_SEMIRAW (E, 2, X);		\
420     }						\
421   while (0)
422 
423 # define FP_PACK_E(val, X)			\
424   do						\
425     {						\
426       _FP_PACK_CANONICAL (E, 2, X);		\
427       FP_PACK_RAW_E ((val), X);			\
428     }						\
429   while (0)
430 
431 # define FP_PACK_EP(val, X)			\
432   do						\
433     {						\
434       _FP_PACK_CANONICAL (E, 2, X);		\
435       FP_PACK_RAW_EP ((val), X);		\
436     }						\
437   while (0)
438 
439 # define FP_PACK_SEMIRAW_E(val, X)		\
440   do						\
441     {						\
442       _FP_PACK_SEMIRAW (E, 2, X);		\
443       FP_PACK_RAW_E ((val), X);			\
444     }						\
445   while (0)
446 
447 # define FP_PACK_SEMIRAW_EP(val, X)		\
448   do						\
449     {						\
450       _FP_PACK_SEMIRAW (E, 2, X);		\
451       FP_PACK_RAW_EP ((val), X);		\
452     }						\
453   while (0)
454 
455 # define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 2, X)
456 # define FP_NEG_E(R, X)		_FP_NEG (E, 2, R, X)
457 # define FP_ADD_E(R, X, Y)	_FP_ADD (E, 2, R, X, Y)
458 # define FP_SUB_E(R, X, Y)	_FP_SUB (E, 2, R, X, Y)
459 # define FP_MUL_E(R, X, Y)	_FP_MUL (E, 2, R, X, Y)
460 # define FP_DIV_E(R, X, Y)	_FP_DIV (E, 2, R, X, Y)
461 # define FP_SQRT_E(R, X)	_FP_SQRT (E, 2, R, X)
462 # define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 2, 4, R, X, Y, Z)
463 
464 /* Square root algorithms:
465    We have just one right now, maybe Newton approximation
466    should be added for those machines where division is fast.
467    We optimize it by doing most of the calculations
468    in one UWtype registers instead of two, although we don't
469    have to.  */
470 # define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
471   do							\
472     {							\
473       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
474       _FP_FRAC_SRL_2 (X, (_FP_WORKBITS));		\
475       while (q)						\
476 	{						\
477 	  T##_f0 = S##_f0 + (q);			\
478 	  if (T##_f0 <= X##_f0)				\
479 	    {						\
480 	      S##_f0 = T##_f0 + (q);			\
481 	      X##_f0 -= T##_f0;				\
482 	      R##_f0 += (q);				\
483 	    }						\
484 	  _FP_FRAC_SLL_1 (X, 1);			\
485 	  (q) >>= 1;					\
486 	}						\
487       _FP_FRAC_SLL_2 (R, (_FP_WORKBITS));		\
488       if (X##_f0)					\
489 	{						\
490 	  if (S##_f0 < X##_f0)				\
491 	    R##_f0 |= _FP_WORK_ROUND;			\
492 	  R##_f0 |= _FP_WORK_STICKY;			\
493 	}						\
494     }							\
495   while (0)
496 
497 # define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 2, (r), X, Y, (un), (ex))
498 # define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 2, (r), X, Y, (ex))
499 # define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 2, (r), X, Y, (ex))
500 
501 # define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 2, (r), X, (rsz), (rsg))
502 # define FP_TO_INT_ROUND_E(r, X, rsz, rsg)	\
503   _FP_TO_INT_ROUND (E, 2, (r), X, (rsz), (rsg))
504 # define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 2, X, (r), (rs), rt)
505 
506 # define _FP_FRAC_HIGH_E(X)	(X##_f1)
507 # define _FP_FRAC_HIGH_RAW_E(X)	(X##_f0)
508 
509 # define _FP_FRAC_HIGH_DW_E(X)	(X##_f[2])
510 
511 #endif /* not _FP_W_TYPE_SIZE < 64 */
512 
513 #endif /* !SOFT_FP_EXTENDED_H */
514