extended.h revision 1.1.1.6
1/* Software floating-point emulation.
2   Definitions for IEEE Extended Precision.
3   Copyright (C) 1999-2019 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
69typedef float XFtype __attribute__ ((mode (XF)));
70
71#if _FP_W_TYPE_SIZE < 64
72
73union _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;
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##_f[1] &= ~_FP_IMPLBIT_E;			\
108      X##_e  = FP_UNPACK_RAW_E_flo.bits.exp;		\
109      X##_s  = FP_UNPACK_RAW_E_flo.bits.sign;		\
110    }							\
111  while (0)
112
113# define FP_UNPACK_RAW_EP(X, val)			\
114  do							\
115    {							\
116      union _FP_UNION_E *FP_UNPACK_RAW_EP_flo		\
117	= (union _FP_UNION_E *) (val);			\
118							\
119      X##_f[2] = 0;					\
120      X##_f[3] = 0;					\
121      X##_f[0] = FP_UNPACK_RAW_EP_flo->bits.frac0;	\
122      X##_f[1] = FP_UNPACK_RAW_EP_flo->bits.frac1;	\
123      X##_f[1] &= ~_FP_IMPLBIT_E;			\
124      X##_e  = FP_UNPACK_RAW_EP_flo->bits.exp;		\
125      X##_s  = FP_UNPACK_RAW_EP_flo->bits.sign;		\
126    }							\
127  while (0)
128
129# define FP_PACK_RAW_E(val, X)			\
130  do						\
131    {						\
132      union _FP_UNION_E FP_PACK_RAW_E_flo;	\
133						\
134      if (X##_e)				\
135	X##_f[1] |= _FP_IMPLBIT_E;		\
136      else					\
137	X##_f[1] &= ~(_FP_IMPLBIT_E);		\
138      FP_PACK_RAW_E_flo.bits.frac0 = X##_f[0];	\
139      FP_PACK_RAW_E_flo.bits.frac1 = X##_f[1];	\
140      FP_PACK_RAW_E_flo.bits.exp   = X##_e;	\
141      FP_PACK_RAW_E_flo.bits.sign  = X##_s;	\
142						\
143      (val) = FP_PACK_RAW_E_flo.flt;		\
144    }						\
145  while (0)
146
147# define FP_PACK_RAW_EP(val, X)				\
148  do							\
149    {							\
150      if (!FP_INHIBIT_RESULTS)				\
151	{						\
152	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
153	    = (union _FP_UNION_E *) (val);		\
154							\
155	  if (X##_e)					\
156	    X##_f[1] |= _FP_IMPLBIT_E;			\
157	  else						\
158	    X##_f[1] &= ~(_FP_IMPLBIT_E);		\
159	  FP_PACK_RAW_EP_flo->bits.frac0 = X##_f[0];	\
160	  FP_PACK_RAW_EP_flo->bits.frac1 = X##_f[1];	\
161	  FP_PACK_RAW_EP_flo->bits.exp   = X##_e;	\
162	  FP_PACK_RAW_EP_flo->bits.sign  = X##_s;	\
163	}						\
164    }							\
165  while (0)
166
167# define FP_UNPACK_E(X, val)			\
168  do						\
169    {						\
170      FP_UNPACK_RAW_E (X, (val));		\
171      _FP_UNPACK_CANONICAL (E, 4, X);		\
172    }						\
173  while (0)
174
175# define FP_UNPACK_EP(X, val)			\
176  do						\
177    {						\
178      FP_UNPACK_RAW_EP (X, (val));		\
179      _FP_UNPACK_CANONICAL (E, 4, X);		\
180    }						\
181  while (0)
182
183# define FP_UNPACK_SEMIRAW_E(X, val)		\
184  do						\
185    {						\
186      FP_UNPACK_RAW_E (X, (val));		\
187      _FP_UNPACK_SEMIRAW (E, 4, X);		\
188    }						\
189  while (0)
190
191# define FP_UNPACK_SEMIRAW_EP(X, val)		\
192  do						\
193    {						\
194      FP_UNPACK_RAW_EP (X, (val));		\
195      _FP_UNPACK_SEMIRAW (E, 4, X);		\
196    }						\
197  while (0)
198
199# define FP_PACK_E(val, X)			\
200  do						\
201    {						\
202      _FP_PACK_CANONICAL (E, 4, X);		\
203      FP_PACK_RAW_E ((val), X);			\
204    }						\
205  while (0)
206
207# define FP_PACK_EP(val, X)			\
208  do						\
209    {						\
210      _FP_PACK_CANONICAL (E, 4, X);		\
211      FP_PACK_RAW_EP ((val), X);		\
212    }						\
213  while (0)
214
215# define FP_PACK_SEMIRAW_E(val, X)		\
216  do						\
217    {						\
218      _FP_PACK_SEMIRAW (E, 4, X);		\
219      FP_PACK_RAW_E ((val), X);			\
220    }						\
221  while (0)
222
223# define FP_PACK_SEMIRAW_EP(val, X)		\
224  do						\
225    {						\
226      _FP_PACK_SEMIRAW (E, 4, X);		\
227      FP_PACK_RAW_EP ((val), X);		\
228    }						\
229  while (0)
230
231# define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 4, X)
232# define FP_NEG_E(R, X)		_FP_NEG (E, 4, R, X)
233# define FP_ADD_E(R, X, Y)	_FP_ADD (E, 4, R, X, Y)
234# define FP_SUB_E(R, X, Y)	_FP_SUB (E, 4, R, X, Y)
235# define FP_MUL_E(R, X, Y)	_FP_MUL (E, 4, R, X, Y)
236# define FP_DIV_E(R, X, Y)	_FP_DIV (E, 4, R, X, Y)
237# define FP_SQRT_E(R, X)	_FP_SQRT (E, 4, R, X)
238# define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 4, 8, R, X, Y, Z)
239
240/* Square root algorithms:
241   We have just one right now, maybe Newton approximation
242   should be added for those machines where division is fast.
243   This has special _E version because standard _4 square
244   root would not work (it has to start normally with the
245   second word and not the first), but as we have to do it
246   anyway, we optimize it by doing most of the calculations
247   in two UWtype registers instead of four.  */
248
249# define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
250  do							\
251    {							\
252      (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
253      _FP_FRAC_SRL_4 (X, (_FP_WORKBITS));		\
254      while (q)						\
255	{						\
256	  T##_f[1] = S##_f[1] + (q);			\
257	  if (T##_f[1] <= X##_f[1])			\
258	    {						\
259	      S##_f[1] = T##_f[1] + (q);		\
260	      X##_f[1] -= T##_f[1];			\
261	      R##_f[1] += (q);				\
262	    }						\
263	  _FP_FRAC_SLL_2 (X, 1);			\
264	  (q) >>= 1;					\
265	}						\
266      (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
267      while (q)						\
268	{						\
269	  T##_f[0] = S##_f[0] + (q);			\
270	  T##_f[1] = S##_f[1];				\
271	  if (T##_f[1] < X##_f[1]			\
272	      || (T##_f[1] == X##_f[1]			\
273		  && T##_f[0] <= X##_f[0]))		\
274	    {						\
275	      S##_f[0] = T##_f[0] + (q);		\
276	      S##_f[1] += (T##_f[0] > S##_f[0]);	\
277	      _FP_FRAC_DEC_2 (X, T);			\
278	      R##_f[0] += (q);				\
279	    }						\
280	  _FP_FRAC_SLL_2 (X, 1);			\
281	  (q) >>= 1;					\
282	}						\
283      _FP_FRAC_SLL_4 (R, (_FP_WORKBITS));		\
284      if (X##_f[0] | X##_f[1])				\
285	{						\
286	  if (S##_f[1] < X##_f[1]			\
287	      || (S##_f[1] == X##_f[1]			\
288		  && S##_f[0] < X##_f[0]))		\
289	    R##_f[0] |= _FP_WORK_ROUND;			\
290	  R##_f[0] |= _FP_WORK_STICKY;			\
291	}						\
292    }							\
293  while (0)
294
295# define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 4, (r), X, Y, (un), (ex))
296# define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 4, (r), X, Y, (ex))
297# define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 4, (r), X, Y, (ex))
298
299# define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 4, (r), X, (rsz), (rsg))
300# define FP_TO_INT_ROUND_E(r, X, rsz, rsg)	\
301  _FP_TO_INT_ROUND (E, 4, (r), X, (rsz), (rsg))
302# define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 4, X, (r), (rs), rt)
303
304# define _FP_FRAC_HIGH_E(X)	(X##_f[2])
305# define _FP_FRAC_HIGH_RAW_E(X)	(X##_f[1])
306
307# define _FP_FRAC_HIGH_DW_E(X)	(X##_f[4])
308
309#else   /* not _FP_W_TYPE_SIZE < 64 */
310union _FP_UNION_E
311{
312  XFtype flt;
313  struct _FP_STRUCT_LAYOUT
314  {
315# if __BYTE_ORDER == __BIG_ENDIAN
316    _FP_W_TYPE pad  : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
317    unsigned sign   : 1;
318    unsigned exp    : _FP_EXPBITS_E;
319    _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
320# else
321    _FP_W_TYPE frac : _FP_W_TYPE_SIZE;
322    unsigned exp    : _FP_EXPBITS_E;
323    unsigned sign   : 1;
324# endif
325  } bits;
326};
327
328# define FP_DECL_E(X)		_FP_DECL (2, X)
329
330# define FP_UNPACK_RAW_E(X, val)		\
331  do						\
332    {						\
333      union _FP_UNION_E FP_UNPACK_RAW_E_flo;	\
334      FP_UNPACK_RAW_E_flo.flt = (val);		\
335						\
336      X##_f0 = FP_UNPACK_RAW_E_flo.bits.frac;	\
337      X##_f0 &= ~_FP_IMPLBIT_E;			\
338      X##_f1 = 0;				\
339      X##_e = FP_UNPACK_RAW_E_flo.bits.exp;	\
340      X##_s = FP_UNPACK_RAW_E_flo.bits.sign;	\
341    }						\
342  while (0)
343
344# define FP_UNPACK_RAW_EP(X, val)		\
345  do						\
346    {						\
347      union _FP_UNION_E *FP_UNPACK_RAW_EP_flo	\
348	= (union _FP_UNION_E *) (val);		\
349						\
350      X##_f0 = FP_UNPACK_RAW_EP_flo->bits.frac;	\
351      X##_f0 &= ~_FP_IMPLBIT_E;			\
352      X##_f1 = 0;				\
353      X##_e = FP_UNPACK_RAW_EP_flo->bits.exp;	\
354      X##_s = FP_UNPACK_RAW_EP_flo->bits.sign;	\
355    }						\
356  while (0)
357
358# define FP_PACK_RAW_E(val, X)			\
359  do						\
360    {						\
361      union _FP_UNION_E FP_PACK_RAW_E_flo;	\
362						\
363      if (X##_e)				\
364	X##_f0 |= _FP_IMPLBIT_E;		\
365      else					\
366	X##_f0 &= ~(_FP_IMPLBIT_E);		\
367      FP_PACK_RAW_E_flo.bits.frac = X##_f0;	\
368      FP_PACK_RAW_E_flo.bits.exp  = X##_e;	\
369      FP_PACK_RAW_E_flo.bits.sign = X##_s;	\
370						\
371      (val) = FP_PACK_RAW_E_flo.flt;		\
372    }						\
373  while (0)
374
375# define FP_PACK_RAW_EP(fs, val, X)			\
376  do							\
377    {							\
378      if (!FP_INHIBIT_RESULTS)				\
379	{						\
380	  union _FP_UNION_E *FP_PACK_RAW_EP_flo		\
381	    = (union _FP_UNION_E *) (val);		\
382							\
383	  if (X##_e)					\
384	    X##_f0 |= _FP_IMPLBIT_E;			\
385	  else						\
386	    X##_f0 &= ~(_FP_IMPLBIT_E);			\
387	  FP_PACK_RAW_EP_flo->bits.frac = X##_f0;	\
388	  FP_PACK_RAW_EP_flo->bits.exp  = X##_e;	\
389	  FP_PACK_RAW_EP_flo->bits.sign = X##_s;	\
390	}						\
391    }							\
392  while (0)
393
394
395# define FP_UNPACK_E(X, val)			\
396  do						\
397    {						\
398      FP_UNPACK_RAW_E (X, (val));		\
399      _FP_UNPACK_CANONICAL (E, 2, X);		\
400    }						\
401  while (0)
402
403# define FP_UNPACK_EP(X, val)			\
404  do						\
405    {						\
406      FP_UNPACK_RAW_EP (X, (val));		\
407      _FP_UNPACK_CANONICAL (E, 2, X);		\
408    }						\
409  while (0)
410
411# define FP_UNPACK_SEMIRAW_E(X, val)		\
412  do						\
413    {						\
414      FP_UNPACK_RAW_E (X, (val));		\
415      _FP_UNPACK_SEMIRAW (E, 2, X);		\
416    }						\
417  while (0)
418
419# define FP_UNPACK_SEMIRAW_EP(X, val)		\
420  do						\
421    {						\
422      FP_UNPACK_RAW_EP (X, (val));		\
423      _FP_UNPACK_SEMIRAW (E, 2, X);		\
424    }						\
425  while (0)
426
427# define FP_PACK_E(val, X)			\
428  do						\
429    {						\
430      _FP_PACK_CANONICAL (E, 2, X);		\
431      FP_PACK_RAW_E ((val), X);			\
432    }						\
433  while (0)
434
435# define FP_PACK_EP(val, X)			\
436  do						\
437    {						\
438      _FP_PACK_CANONICAL (E, 2, X);		\
439      FP_PACK_RAW_EP ((val), X);		\
440    }						\
441  while (0)
442
443# define FP_PACK_SEMIRAW_E(val, X)		\
444  do						\
445    {						\
446      _FP_PACK_SEMIRAW (E, 2, X);		\
447      FP_PACK_RAW_E ((val), X);			\
448    }						\
449  while (0)
450
451# define FP_PACK_SEMIRAW_EP(val, X)		\
452  do						\
453    {						\
454      _FP_PACK_SEMIRAW (E, 2, X);		\
455      FP_PACK_RAW_EP ((val), X);		\
456    }						\
457  while (0)
458
459# define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN (E, 2, X)
460# define FP_NEG_E(R, X)		_FP_NEG (E, 2, R, X)
461# define FP_ADD_E(R, X, Y)	_FP_ADD (E, 2, R, X, Y)
462# define FP_SUB_E(R, X, Y)	_FP_SUB (E, 2, R, X, Y)
463# define FP_MUL_E(R, X, Y)	_FP_MUL (E, 2, R, X, Y)
464# define FP_DIV_E(R, X, Y)	_FP_DIV (E, 2, R, X, Y)
465# define FP_SQRT_E(R, X)	_FP_SQRT (E, 2, R, X)
466# define FP_FMA_E(R, X, Y, Z)	_FP_FMA (E, 2, 4, R, X, Y, Z)
467
468/* Square root algorithms:
469   We have just one right now, maybe Newton approximation
470   should be added for those machines where division is fast.
471   We optimize it by doing most of the calculations
472   in one UWtype registers instead of two, although we don't
473   have to.  */
474# define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
475  do							\
476    {							\
477      (q) = (_FP_W_TYPE) 1 << (_FP_W_TYPE_SIZE - 1);	\
478      _FP_FRAC_SRL_2 (X, (_FP_WORKBITS));		\
479      while (q)						\
480	{						\
481	  T##_f0 = S##_f0 + (q);			\
482	  if (T##_f0 <= X##_f0)				\
483	    {						\
484	      S##_f0 = T##_f0 + (q);			\
485	      X##_f0 -= T##_f0;				\
486	      R##_f0 += (q);				\
487	    }						\
488	  _FP_FRAC_SLL_1 (X, 1);			\
489	  (q) >>= 1;					\
490	}						\
491      _FP_FRAC_SLL_2 (R, (_FP_WORKBITS));		\
492      if (X##_f0)					\
493	{						\
494	  if (S##_f0 < X##_f0)				\
495	    R##_f0 |= _FP_WORK_ROUND;			\
496	  R##_f0 |= _FP_WORK_STICKY;			\
497	}						\
498    }							\
499  while (0)
500
501# define FP_CMP_E(r, X, Y, un, ex)	_FP_CMP (E, 2, (r), X, Y, (un), (ex))
502# define FP_CMP_EQ_E(r, X, Y, ex)	_FP_CMP_EQ (E, 2, (r), X, Y, (ex))
503# define FP_CMP_UNORD_E(r, X, Y, ex)	_FP_CMP_UNORD (E, 2, (r), X, Y, (ex))
504
505# define FP_TO_INT_E(r, X, rsz, rsg)	_FP_TO_INT (E, 2, (r), X, (rsz), (rsg))
506# define FP_TO_INT_ROUND_E(r, X, rsz, rsg)	\
507  _FP_TO_INT_ROUND (E, 2, (r), X, (rsz), (rsg))
508# define FP_FROM_INT_E(X, r, rs, rt)	_FP_FROM_INT (E, 2, X, (r), (rs), rt)
509
510# define _FP_FRAC_HIGH_E(X)	(X##_f1)
511# define _FP_FRAC_HIGH_RAW_E(X)	(X##_f0)
512
513# define _FP_FRAC_HIGH_DW_E(X)	(X##_f[2])
514
515#endif /* not _FP_W_TYPE_SIZE < 64 */
516
517#endif /* !SOFT_FP_EXTENDED_H */
518