xref: /netbsd-src/external/gpl3/gcc.old/dist/libgcc/soft-fp/extended.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Software floating-point emulation.
2    Definitions for IEEE Extended Precision.
3    Copyright (C) 1999-2014 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 #if _FP_W_TYPE_SIZE < 32
31 # error "Here's a nickel, kid. Go buy yourself a real computer."
32 #endif
33 
34 #if _FP_W_TYPE_SIZE < 64
35 # define _FP_FRACTBITS_E	(4*_FP_W_TYPE_SIZE)
36 # define _FP_FRACTBITS_DW_E	(8*_FP_W_TYPE_SIZE)
37 #else
38 # define _FP_FRACTBITS_E	(2*_FP_W_TYPE_SIZE)
39 # define _FP_FRACTBITS_DW_E	(4*_FP_W_TYPE_SIZE)
40 #endif
41 
42 #define _FP_FRACBITS_E		64
43 #define _FP_FRACXBITS_E		(_FP_FRACTBITS_E - _FP_FRACBITS_E)
44 #define _FP_WFRACBITS_E		(_FP_WORKBITS + _FP_FRACBITS_E)
45 #define _FP_WFRACXBITS_E	(_FP_FRACTBITS_E - _FP_WFRACBITS_E)
46 #define _FP_EXPBITS_E		15
47 #define _FP_EXPBIAS_E		16383
48 #define _FP_EXPMAX_E		32767
49 
50 #define _FP_QNANBIT_E		\
51 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-2) % _FP_W_TYPE_SIZE)
52 #define _FP_QNANBIT_SH_E		\
53 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-2+_FP_WORKBITS) % _FP_W_TYPE_SIZE)
54 #define _FP_IMPLBIT_E		\
55 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-1) % _FP_W_TYPE_SIZE)
56 #define _FP_IMPLBIT_SH_E		\
57 	((_FP_W_TYPE) 1 << (_FP_FRACBITS_E-1+_FP_WORKBITS) % _FP_W_TYPE_SIZE)
58 #define _FP_OVERFLOW_E		\
59 	((_FP_W_TYPE) 1 << (_FP_WFRACBITS_E % _FP_W_TYPE_SIZE))
60 
61 #define _FP_WFRACBITS_DW_E	(2 * _FP_WFRACBITS_E)
62 #define _FP_WFRACXBITS_DW_E	(_FP_FRACTBITS_DW_E - _FP_WFRACBITS_DW_E)
63 #define _FP_HIGHBIT_DW_E	\
64   ((_FP_W_TYPE) 1 << (_FP_WFRACBITS_DW_E - 1) % _FP_W_TYPE_SIZE)
65 
66 typedef float XFtype __attribute__ ((mode (XF)));
67 
68 #if _FP_W_TYPE_SIZE < 64
69 
70 union _FP_UNION_E
71 {
72   XFtype flt;
73   struct _FP_STRUCT_LAYOUT
74   {
75 # if __BYTE_ORDER == __BIG_ENDIAN
76     unsigned long pad1 : _FP_W_TYPE_SIZE;
77     unsigned long pad2 : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
78     unsigned long sign : 1;
79     unsigned long exp : _FP_EXPBITS_E;
80     unsigned long frac1 : _FP_W_TYPE_SIZE;
81     unsigned long frac0 : _FP_W_TYPE_SIZE;
82 # else
83     unsigned long frac0 : _FP_W_TYPE_SIZE;
84     unsigned long frac1 : _FP_W_TYPE_SIZE;
85     unsigned exp : _FP_EXPBITS_E;
86     unsigned sign : 1;
87 # endif /* not bigendian */
88   } bits __attribute__ ((packed));
89 };
90 
91 
92 # define FP_DECL_E(X)		_FP_DECL (4, X)
93 
94 # define FP_UNPACK_RAW_E(X, val)			\
95   do							\
96     {							\
97       union _FP_UNION_E FP_UNPACK_RAW_E_flo;		\
98       FP_UNPACK_RAW_E_flo.flt = (val);			\
99 							\
100       X##_f[2] = 0;					\
101       X##_f[3] = 0;					\
102       X##_f[0] = FP_UNPACK_RAW_E_flo.bits.frac0;	\
103       X##_f[1] = FP_UNPACK_RAW_E_flo.bits.frac1;	\
104       X##_e  = FP_UNPACK_RAW_E_flo.bits.exp;		\
105       X##_s  = FP_UNPACK_RAW_E_flo.bits.sign;		\
106     }							\
107   while (0)
108 
109 # define FP_UNPACK_RAW_EP(X, val)			\
110   do							\
111     {							\
112       union _FP_UNION_E *FP_UNPACK_RAW_EP_flo		\
113 	= (union _FP_UNION_E *) (val);			\
114 							\
115       X##_f[2] = 0;					\
116       X##_f[3] = 0;					\
117       X##_f[0] = FP_UNPACK_RAW_EP_flo->bits.frac0;	\
118       X##_f[1] = FP_UNPACK_RAW_EP_flo->bits.frac1;	\
119       X##_e  = FP_UNPACK_RAW_EP_flo->bits.exp;		\
120       X##_s  = FP_UNPACK_RAW_EP_flo->bits.sign;		\
121     }							\
122   while (0)
123 
124 # define FP_PACK_RAW_E(val, X)			\
125   do						\
126     {						\
127       union _FP_UNION_E FP_PACK_RAW_E_flo;	\
128 						\
129       if (X##_e)				\
130 	X##_f[1] |= _FP_IMPLBIT_E;		\
131       else					\
132 	X##_f[1] &= ~(_FP_IMPLBIT_E);		\
133       FP_PACK_RAW_E_flo.bits.frac0 = X##_f[0];	\
134       FP_PACK_RAW_E_flo.bits.frac1 = X##_f[1];	\
135       FP_PACK_RAW_E_flo.bits.exp   = X##_e;	\
136       FP_PACK_RAW_E_flo.bits.sign  = X##_s;	\
137 						\
138       (val) = FP_PACK_RAW_E_flo.flt;		\
139     }						\
140   while (0)
141 
142 # define FP_PACK_RAW_EP(val, X)				\
143   do							\
144     {							\
145       if (!FP_INHIBIT_RESULTS)				\
146 	{						\
147 	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
148 	    = (union _FP_UNION_E *) (val);		\
149 							\
150 	  if (X##_e)					\
151 	    X##_f[1] |= _FP_IMPLBIT_E;			\
152 	  else						\
153 	    X##_f[1] &= ~(_FP_IMPLBIT_E);		\
154 	  FP_PACK_RAW_EP_flo->bits.frac0 = X##_f[0];	\
155 	  FP_PACK_RAW_EP_flo->bits.frac1 = X##_f[1];	\
156 	  FP_PACK_RAW_EP_flo->bits.exp   = X##_e;	\
157 	  FP_PACK_RAW_EP_flo->bits.sign  = X##_s;	\
158 	}						\
159     }							\
160   while (0)
161 
162 # define FP_UNPACK_E(X, val)			\
163   do						\
164     {						\
165       FP_UNPACK_RAW_E (X, (val));		\
166       _FP_UNPACK_CANONICAL (E, 4, X);		\
167     }						\
168   while (0)
169 
170 # define FP_UNPACK_EP(X, val)			\
171   do						\
172     {						\
173       FP_UNPACK_RAW_EP (X, (val));		\
174       _FP_UNPACK_CANONICAL (E, 4, X);		\
175     }						\
176   while (0)
177 
178 # define FP_UNPACK_SEMIRAW_E(X, val)		\
179   do						\
180     {						\
181       FP_UNPACK_RAW_E (X, (val));		\
182       _FP_UNPACK_SEMIRAW (E, 4, X);		\
183     }						\
184   while (0)
185 
186 # define FP_UNPACK_SEMIRAW_EP(X, val)		\
187   do						\
188     {						\
189       FP_UNPACK_RAW_EP (X, (val));		\
190       _FP_UNPACK_SEMIRAW (E, 4, X);		\
191     }						\
192   while (0)
193 
194 # define FP_PACK_E(val, X)			\
195   do						\
196     {						\
197       _FP_PACK_CANONICAL (E, 4, X);		\
198       FP_PACK_RAW_E ((val), X);			\
199     }						\
200   while (0)
201 
202 # define FP_PACK_EP(val, X)			\
203   do						\
204     {						\
205       _FP_PACK_CANONICAL (E, 4, X);		\
206       FP_PACK_RAW_EP ((val), X);		\
207     }						\
208   while (0)
209 
210 # define FP_PACK_SEMIRAW_E(val, X)		\
211   do						\
212     {						\
213       _FP_PACK_SEMIRAW (E, 4, X);		\
214       FP_PACK_RAW_E ((val), X);			\
215     }						\
216   while (0)
217 
218 # define FP_PACK_SEMIRAW_EP(val, X)		\
219   do						\
220     {						\
221       _FP_PACK_SEMIRAW (E, 4, X);		\
222       FP_PACK_RAW_EP ((val), X);		\
223     }						\
224   while (0)
225 
226 # define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 4, X)
227 # define FP_NEG_E(R, X)		_FP_NEG (E, 4, R, X)
228 # define FP_ADD_E(R, X, Y)	_FP_ADD (E, 4, R, X, Y)
229 # define FP_SUB_E(R, X, Y)	_FP_SUB (E, 4, R, X, Y)
230 # define FP_MUL_E(R, X, Y)	_FP_MUL (E, 4, R, X, Y)
231 # define FP_DIV_E(R, X, Y)	_FP_DIV (E, 4, R, X, Y)
232 # define FP_SQRT_E(R, X)	_FP_SQRT (E, 4, R, X)
233 # define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 4, 8, R, X, Y, Z)
234 
235 /* Square root algorithms:
236    We have just one right now, maybe Newton approximation
237    should be added for those machines where division is fast.
238    This has special _E version because standard _4 square
239    root would not work (it has to start normally with the
240    second word and not the first), but as we have to do it
241    anyway, we optimize it by doing most of the calculations
242    in two UWtype registers instead of four.  */
243 
244 # define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
245   do							\
246     {							\
247       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
248       _FP_FRAC_SRL_4 (X, (_FP_WORKBITS));		\
249       while (q)						\
250 	{						\
251 	  T##_f[1] = S##_f[1] + (q);			\
252 	  if (T##_f[1] <= X##_f[1])			\
253 	    {						\
254 	      S##_f[1] = T##_f[1] + (q);		\
255 	      X##_f[1] -= T##_f[1];			\
256 	      R##_f[1] += (q);				\
257 	    }						\
258 	  _FP_FRAC_SLL_2 (X, 1);			\
259 	  (q) >>= 1;					\
260 	}						\
261       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
262       while (q)						\
263 	{						\
264 	  T##_f[0] = S##_f[0] + (q);			\
265 	  T##_f[1] = S##_f[1];				\
266 	  if (T##_f[1] < X##_f[1]			\
267 	      || (T##_f[1] == X##_f[1]			\
268 		  && T##_f[0] <= X##_f[0]))		\
269 	    {						\
270 	      S##_f[0] = T##_f[0] + (q);		\
271 	      S##_f[1] += (T##_f[0] > S##_f[0]);	\
272 	      _FP_FRAC_DEC_2 (X, T);			\
273 	      R##_f[0] += (q);				\
274 	    }						\
275 	  _FP_FRAC_SLL_2 (X, 1);			\
276 	  (q) >>= 1;					\
277 	}						\
278       _FP_FRAC_SLL_4 (R, (_FP_WORKBITS));		\
279       if (X##_f[0] | X##_f[1])				\
280 	{						\
281 	  if (S##_f[1] < X##_f[1]			\
282 	      || (S##_f[1] == X##_f[1]			\
283 		  && S##_f[0] < X##_f[0]))		\
284 	    R##_f[0] |= _FP_WORK_ROUND;			\
285 	  R##_f[0] |= _FP_WORK_STICKY;			\
286 	}						\
287     }							\
288   while (0)
289 
290 # define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 4, (r), X, Y, (un), (ex))
291 # define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 4, (r), X, Y, (ex))
292 # define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 4, (r), X, Y, (ex))
293 
294 # define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 4, (r), X, (rsz), (rsg))
295 # define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 4, X, (r), (rs), rt)
296 
297 # define _FP_FRAC_HIGH_E(X)	(X##_f[2])
298 # define _FP_FRAC_HIGH_RAW_E(X)	(X##_f[1])
299 
300 # define _FP_FRAC_HIGH_DW_E(X)	(X##_f[4])
301 
302 #else   /* not _FP_W_TYPE_SIZE < 64 */
303 union _FP_UNION_E
304 {
305   XFtype flt;
306   struct _FP_STRUCT_LAYOUT
307   {
308 # if __BYTE_ORDER == __BIG_ENDIAN
309     _FP_W_TYPE pad  : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
310     unsigned sign   : 1;
311     unsigned exp    : _FP_EXPBITS_E;
312     _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
313 # else
314     _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
315     unsigned exp    : _FP_EXPBITS_E;
316     unsigned sign   : 1;
317 # endif
318   } bits;
319 };
320 
321 # define FP_DECL_E(X)		_FP_DECL (2, X)
322 
323 # define FP_UNPACK_RAW_E(X, val)		\
324   do						\
325     {						\
326       union _FP_UNION_E FP_UNPACK_RAW_E_flo;	\
327       FP_UNPACK_RAW_E_flo.flt = (val);		\
328 						\
329       X##_f0 = FP_UNPACK_RAW_E_flo.bits.frac;	\
330       X##_f1 = 0;				\
331       X##_e = FP_UNPACK_RAW_E_flo.bits.exp;	\
332       X##_s = FP_UNPACK_RAW_E_flo.bits.sign;	\
333     }						\
334   while (0)
335 
336 # define FP_UNPACK_RAW_EP(X, val)		\
337   do						\
338     {						\
339       union _FP_UNION_E *FP_UNPACK_RAW_EP_flo	\
340 	= (union _FP_UNION_E *) (val);		\
341 						\
342       X##_f0 = FP_UNPACK_RAW_EP_flo->bits.frac;	\
343       X##_f1 = 0;				\
344       X##_e = FP_UNPACK_RAW_EP_flo->bits.exp;	\
345       X##_s = FP_UNPACK_RAW_EP_flo->bits.sign;	\
346     }						\
347   while (0)
348 
349 # define FP_PACK_RAW_E(val, X)			\
350   do						\
351     {						\
352       union _FP_UNION_E FP_PACK_RAW_E_flo;	\
353 						\
354       if (X##_e)				\
355 	X##_f0 |= _FP_IMPLBIT_E;		\
356       else					\
357 	X##_f0 &= ~(_FP_IMPLBIT_E);		\
358       FP_PACK_RAW_E_flo.bits.frac = X##_f0;	\
359       FP_PACK_RAW_E_flo.bits.exp  = X##_e;	\
360       FP_PACK_RAW_E_flo.bits.sign = X##_s;	\
361 						\
362       (val) = FP_PACK_RAW_E_flo.flt;		\
363     }						\
364   while (0)
365 
366 # define FP_PACK_RAW_EP(fs, val, X)			\
367   do							\
368     {							\
369       if (!FP_INHIBIT_RESULTS)				\
370 	{						\
371 	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
372 	    = (union _FP_UNION_E *) (val);		\
373 							\
374 	  if (X##_e)					\
375 	    X##_f0 |= _FP_IMPLBIT_E;			\
376 	  else						\
377 	    X##_f0 &= ~(_FP_IMPLBIT_E);			\
378 	  FP_PACK_RAW_EP_flo->bits.frac = X##_f0;	\
379 	  FP_PACK_RAW_EP_flo->bits.exp  = X##_e;	\
380 	  FP_PACK_RAW_EP_flo->bits.sign = X##_s;	\
381 	}						\
382     }							\
383   while (0)
384 
385 
386 # define FP_UNPACK_E(X, val)			\
387   do						\
388     {						\
389       FP_UNPACK_RAW_E (X, (val));		\
390       _FP_UNPACK_CANONICAL (E, 2, X);		\
391     }						\
392   while (0)
393 
394 # define FP_UNPACK_EP(X, val)			\
395   do						\
396     {						\
397       FP_UNPACK_RAW_EP (X, (val));		\
398       _FP_UNPACK_CANONICAL (E, 2, X);		\
399     }						\
400   while (0)
401 
402 # define FP_UNPACK_SEMIRAW_E(X, val)		\
403   do						\
404     {						\
405       FP_UNPACK_RAW_E (X, (val));		\
406       _FP_UNPACK_SEMIRAW (E, 2, X);		\
407     }						\
408   while (0)
409 
410 # define FP_UNPACK_SEMIRAW_EP(X, val)		\
411   do						\
412     {						\
413       FP_UNPACK_RAW_EP (X, (val));		\
414       _FP_UNPACK_SEMIRAW (E, 2, X);		\
415     }						\
416   while (0)
417 
418 # define FP_PACK_E(val, X)			\
419   do						\
420     {						\
421       _FP_PACK_CANONICAL (E, 2, X);		\
422       FP_PACK_RAW_E ((val), X);			\
423     }						\
424   while (0)
425 
426 # define FP_PACK_EP(val, X)			\
427   do						\
428     {						\
429       _FP_PACK_CANONICAL (E, 2, X);		\
430       FP_PACK_RAW_EP ((val), X);		\
431     }						\
432   while (0)
433 
434 # define FP_PACK_SEMIRAW_E(val, X)		\
435   do						\
436     {						\
437       _FP_PACK_SEMIRAW (E, 2, X);		\
438       FP_PACK_RAW_E ((val), X);			\
439     }						\
440   while (0)
441 
442 # define FP_PACK_SEMIRAW_EP(val, X)		\
443   do						\
444     {						\
445       _FP_PACK_SEMIRAW (E, 2, X);		\
446       FP_PACK_RAW_EP ((val), X);		\
447     }						\
448   while (0)
449 
450 # define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 2, X)
451 # define FP_NEG_E(R, X)		_FP_NEG (E, 2, R, X)
452 # define FP_ADD_E(R, X, Y)	_FP_ADD (E, 2, R, X, Y)
453 # define FP_SUB_E(R, X, Y)	_FP_SUB (E, 2, R, X, Y)
454 # define FP_MUL_E(R, X, Y)	_FP_MUL (E, 2, R, X, Y)
455 # define FP_DIV_E(R, X, Y)	_FP_DIV (E, 2, R, X, Y)
456 # define FP_SQRT_E(R, X)	_FP_SQRT (E, 2, R, X)
457 # define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 2, 4, R, X, Y, Z)
458 
459 /* Square root algorithms:
460    We have just one right now, maybe Newton approximation
461    should be added for those machines where division is fast.
462    We optimize it by doing most of the calculations
463    in one UWtype registers instead of two, although we don't
464    have to.  */
465 # define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
466   do							\
467     {							\
468       (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
469       _FP_FRAC_SRL_2 (X, (_FP_WORKBITS));		\
470       while (q)						\
471 	{						\
472 	  T##_f0 = S##_f0 + (q);			\
473 	  if (T##_f0 <= X##_f0)				\
474 	    {						\
475 	      S##_f0 = T##_f0 + (q);			\
476 	      X##_f0 -= T##_f0;				\
477 	      R##_f0 += (q);				\
478 	    }						\
479 	  _FP_FRAC_SLL_1 (X, 1);			\
480 	  (q) >>= 1;					\
481 	}						\
482       _FP_FRAC_SLL_2 (R, (_FP_WORKBITS));		\
483       if (X##_f0)					\
484 	{						\
485 	  if (S##_f0 < X##_f0)				\
486 	    R##_f0 |= _FP_WORK_ROUND;			\
487 	  R##_f0 |= _FP_WORK_STICKY;			\
488 	}						\
489     }							\
490   while (0)
491 
492 # define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 2, (r), X, Y, (un), (ex))
493 # define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 2, (r), X, Y, (ex))
494 # define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 2, (r), X, Y, (ex))
495 
496 # define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 2, (r), X, (rsz), (rsg))
497 # define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 2, X, (r), (rs), rt)
498 
499 # define _FP_FRAC_HIGH_E(X)	(X##_f1)
500 # define _FP_FRAC_HIGH_RAW_E(X)	(X##_f0)
501 
502 # define _FP_FRAC_HIGH_DW_E(X)	(X##_f[2])
503 
504 #endif /* not _FP_W_TYPE_SIZE < 64 */
505