1/* Software floating-point emulation.
2   Definitions for IEEE Extended Precision.
3   Copyright (C) 1999 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 Library General Public License as
9   published by the Free Software Foundation; either version 2 of the
10   License, or (at your option) any later version.
11
12   The GNU C Library is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15   Library General Public License for more details.
16
17   You should have received a copy of the GNU Library General Public
18   License along with the GNU C Library; see the file COPYING.LIB.  If
19   not, write to the Free Software Foundation, Inc.,
20   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
21
22
23#ifndef    __MATH_EMU_EXTENDED_H__
24#define    __MATH_EMU_EXTENDED_H__
25
26#if _FP_W_TYPE_SIZE < 32
27#error "Here's a nickel, kid. Go buy yourself a real computer."
28#endif
29
30#if _FP_W_TYPE_SIZE < 64
31#define _FP_FRACTBITS_E         (4*_FP_W_TYPE_SIZE)
32#else
33#define _FP_FRACTBITS_E		(2*_FP_W_TYPE_SIZE)
34#endif
35
36#define _FP_FRACBITS_E		64
37#define _FP_FRACXBITS_E		(_FP_FRACTBITS_E - _FP_FRACBITS_E)
38#define _FP_WFRACBITS_E		(_FP_WORKBITS + _FP_FRACBITS_E)
39#define _FP_WFRACXBITS_E	(_FP_FRACTBITS_E - _FP_WFRACBITS_E)
40#define _FP_EXPBITS_E		15
41#define _FP_EXPBIAS_E		16383
42#define _FP_EXPMAX_E		32767
43
44#define _FP_QNANBIT_E		\
45	((_FP_W_TYPE)1 << (_FP_FRACBITS_E-2) % _FP_W_TYPE_SIZE)
46#define _FP_IMPLBIT_E		\
47	((_FP_W_TYPE)1 << (_FP_FRACBITS_E-1) % _FP_W_TYPE_SIZE)
48#define _FP_OVERFLOW_E		\
49	((_FP_W_TYPE)1 << (_FP_WFRACBITS_E % _FP_W_TYPE_SIZE))
50
51#if _FP_W_TYPE_SIZE < 64
52
53union _FP_UNION_E
54{
55   long double flt;
56   struct
57   {
58#if __BYTE_ORDER == __BIG_ENDIAN
59      unsigned long pad1 : _FP_W_TYPE_SIZE;
60      unsigned long pad2 : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
61      unsigned long sign : 1;
62      unsigned long exp : _FP_EXPBITS_E;
63      unsigned long frac1 : _FP_W_TYPE_SIZE;
64      unsigned long frac0 : _FP_W_TYPE_SIZE;
65#else
66      unsigned long frac0 : _FP_W_TYPE_SIZE;
67      unsigned long frac1 : _FP_W_TYPE_SIZE;
68      unsigned exp : _FP_EXPBITS_E;
69      unsigned sign : 1;
70#endif /* not bigendian */
71   } bits __attribute__((packed));
72};
73
74
75#define FP_DECL_E(X)		_FP_DECL(4,X)
76
77#define FP_UNPACK_RAW_E(X, val)				\
78  do {							\
79    union _FP_UNION_E _flo; _flo.flt = (val);		\
80							\
81    X##_f[2] = 0; X##_f[3] = 0;				\
82    X##_f[0] = _flo.bits.frac0;				\
83    X##_f[1] = _flo.bits.frac1;				\
84    X##_e  = _flo.bits.exp;				\
85    X##_s  = _flo.bits.sign;				\
86    if (!X##_e && (X##_f[1] || X##_f[0])		\
87        && !(X##_f[1] & _FP_IMPLBIT_E))			\
88      {							\
89        X##_e++;					\
90        FP_SET_EXCEPTION(FP_EX_DENORM);			\
91      }							\
92  } while (0)
93
94#define FP_UNPACK_RAW_EP(X, val)			\
95  do {							\
96    union _FP_UNION_E *_flo =				\
97    (union _FP_UNION_E *)(val);				\
98							\
99    X##_f[2] = 0; X##_f[3] = 0;				\
100    X##_f[0] = _flo->bits.frac0;			\
101    X##_f[1] = _flo->bits.frac1;			\
102    X##_e  = _flo->bits.exp;				\
103    X##_s  = _flo->bits.sign;				\
104    if (!X##_e && (X##_f[1] || X##_f[0])		\
105        && !(X##_f[1] & _FP_IMPLBIT_E))			\
106      {							\
107        X##_e++;					\
108        FP_SET_EXCEPTION(FP_EX_DENORM);			\
109      }							\
110  } while (0)
111
112#define FP_PACK_RAW_E(val, X)				\
113  do {							\
114    union _FP_UNION_E _flo;				\
115							\
116    if (X##_e) X##_f[1] |= _FP_IMPLBIT_E;		\
117    else X##_f[1] &= ~(_FP_IMPLBIT_E);			\
118    _flo.bits.frac0 = X##_f[0];				\
119    _flo.bits.frac1 = X##_f[1];				\
120    _flo.bits.exp   = X##_e;				\
121    _flo.bits.sign  = X##_s;				\
122							\
123    (val) = _flo.flt;					\
124  } while (0)
125
126#define FP_PACK_RAW_EP(val, X)				\
127  do {							\
128    if (!FP_INHIBIT_RESULTS)				\
129      {							\
130	union _FP_UNION_E *_flo =			\
131	  (union _FP_UNION_E *)(val);			\
132							\
133	if (X##_e) X##_f[1] |= _FP_IMPLBIT_E;		\
134	else X##_f[1] &= ~(_FP_IMPLBIT_E);		\
135	_flo->bits.frac0 = X##_f[0];			\
136	_flo->bits.frac1 = X##_f[1];			\
137	_flo->bits.exp   = X##_e;			\
138	_flo->bits.sign  = X##_s;			\
139      }							\
140  } while (0)
141
142#define FP_UNPACK_E(X,val)		\
143  do {					\
144    FP_UNPACK_RAW_E(X,val);		\
145    _FP_UNPACK_CANONICAL(E,4,X);	\
146  } while (0)
147
148#define FP_UNPACK_EP(X,val)		\
149  do {					\
150    FP_UNPACK_RAW_2_P(X,val);		\
151    _FP_UNPACK_CANONICAL(E,4,X);	\
152  } while (0)
153
154#define FP_PACK_E(val,X)		\
155  do {					\
156    _FP_PACK_CANONICAL(E,4,X);		\
157    FP_PACK_RAW_E(val,X);		\
158  } while (0)
159
160#define FP_PACK_EP(val,X)		\
161  do {					\
162    _FP_PACK_CANONICAL(E,4,X);		\
163    FP_PACK_RAW_EP(val,X);		\
164  } while (0)
165
166#define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN(E,4,X)
167#define FP_NEG_E(R,X)		_FP_NEG(E,4,R,X)
168#define FP_ADD_E(R,X,Y)		_FP_ADD(E,4,R,X,Y)
169#define FP_SUB_E(R,X,Y)		_FP_SUB(E,4,R,X,Y)
170#define FP_MUL_E(R,X,Y)		_FP_MUL(E,4,R,X,Y)
171#define FP_DIV_E(R,X,Y)		_FP_DIV(E,4,R,X,Y)
172#define FP_SQRT_E(R,X)		_FP_SQRT(E,4,R,X)
173
174/*
175 * Square root algorithms:
176 * We have just one right now, maybe Newton approximation
177 * should be added for those machines where division is fast.
178 * This has special _E version because standard _4 square
179 * root would not work (it has to start normally with the
180 * second word and not the first), but as we have to do it
181 * anyway, we optimize it by doing most of the calculations
182 * in two UWtype registers instead of four.
183 */
184
185#define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
186  do {							\
187    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
188    _FP_FRAC_SRL_4(X, (_FP_WORKBITS));			\
189    while (q)						\
190      {							\
191	T##_f[1] = S##_f[1] + q;			\
192	if (T##_f[1] <= X##_f[1])			\
193	  {						\
194	    S##_f[1] = T##_f[1] + q;			\
195	    X##_f[1] -= T##_f[1];			\
196	    R##_f[1] += q;				\
197	  }						\
198	_FP_FRAC_SLL_2(X, 1);				\
199	q >>= 1;					\
200      }							\
201    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
202    while (q)						\
203      {							\
204	T##_f[0] = S##_f[0] + q;			\
205	T##_f[1] = S##_f[1];				\
206	if (T##_f[1] < X##_f[1] || 			\
207	    (T##_f[1] == X##_f[1] &&			\
208	     T##_f[0] <= X##_f[0]))			\
209	  {						\
210	    S##_f[0] = T##_f[0] + q;			\
211	    S##_f[1] += (T##_f[0] > S##_f[0]);		\
212	    _FP_FRAC_DEC_2(X, T);			\
213	    R##_f[0] += q;				\
214	  }						\
215	_FP_FRAC_SLL_2(X, 1);				\
216	q >>= 1;					\
217      }							\
218    _FP_FRAC_SLL_4(R, (_FP_WORKBITS));			\
219    if (X##_f[0] | X##_f[1])				\
220      {							\
221	if (S##_f[1] < X##_f[1] || 			\
222	    (S##_f[1] == X##_f[1] &&			\
223	     S##_f[0] < X##_f[0]))			\
224	  R##_f[0] |= _FP_WORK_ROUND;			\
225	R##_f[0] |= _FP_WORK_STICKY;			\
226      }							\
227  } while (0)
228
229#define FP_CMP_E(r,X,Y,un)	_FP_CMP(E,4,r,X,Y,un)
230#define FP_CMP_EQ_E(r,X,Y)	_FP_CMP_EQ(E,4,r,X,Y)
231
232#define FP_TO_INT_E(r,X,rsz,rsg)	_FP_TO_INT(E,4,r,X,rsz,rsg)
233#define FP_TO_INT_ROUND_E(r,X,rsz,rsg)	_FP_TO_INT_ROUND(E,4,r,X,rsz,rsg)
234#define FP_FROM_INT_E(X,r,rs,rt)	_FP_FROM_INT(E,4,X,r,rs,rt)
235
236#define _FP_FRAC_HIGH_E(X)	(X##_f[2])
237#define _FP_FRAC_HIGH_RAW_E(X)	(X##_f[1])
238
239#else   /* not _FP_W_TYPE_SIZE < 64 */
240union _FP_UNION_E
241{
242  long double flt /* __attribute__((mode(TF))) */ ;
243  struct {
244#if __BYTE_ORDER == __BIG_ENDIAN
245    unsigned long pad : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
246    unsigned sign  : 1;
247    unsigned exp   : _FP_EXPBITS_E;
248    unsigned long frac : _FP_W_TYPE_SIZE;
249#else
250    unsigned long frac : _FP_W_TYPE_SIZE;
251    unsigned exp   : _FP_EXPBITS_E;
252    unsigned sign  : 1;
253#endif
254  } bits;
255};
256
257#define FP_DECL_E(X)		_FP_DECL(2,X)
258
259#define FP_UNPACK_RAW_E(X, val)					\
260  do {								\
261    union _FP_UNION_E _flo; _flo.flt = (val);			\
262								\
263    X##_f0 = _flo.bits.frac;					\
264    X##_f1 = 0;							\
265    X##_e = _flo.bits.exp;					\
266    X##_s = _flo.bits.sign;					\
267    if (!X##_e && X##_f0 && !(X##_f0 & _FP_IMPLBIT_E))		\
268      {								\
269        X##_e++;						\
270        FP_SET_EXCEPTION(FP_EX_DENORM);				\
271      }								\
272  } while (0)
273
274#define FP_UNPACK_RAW_EP(X, val)				\
275  do {								\
276    union _FP_UNION_E *_flo =					\
277      (union _FP_UNION_E *)(val);				\
278								\
279    X##_f0 = _flo->bits.frac;					\
280    X##_f1 = 0;							\
281    X##_e = _flo->bits.exp;					\
282    X##_s = _flo->bits.sign;					\
283    if (!X##_e && X##_f0 && !(X##_f0 & _FP_IMPLBIT_E))		\
284      {								\
285        X##_e++;						\
286        FP_SET_EXCEPTION(FP_EX_DENORM);				\
287      }								\
288  } while (0)
289
290#define FP_PACK_RAW_E(val, X)					\
291  do {								\
292    union _FP_UNION_E _flo;					\
293								\
294    if (X##_e) X##_f0 |= _FP_IMPLBIT_E;				\
295    else X##_f0 &= ~(_FP_IMPLBIT_E);				\
296    _flo.bits.frac = X##_f0;					\
297    _flo.bits.exp  = X##_e;					\
298    _flo.bits.sign = X##_s;					\
299								\
300    (val) = _flo.flt;						\
301  } while (0)
302
303#define FP_PACK_RAW_EP(fs, val, X)				\
304  do {								\
305    if (!FP_INHIBIT_RESULTS)					\
306      {								\
307	union _FP_UNION_E *_flo =				\
308	  (union _FP_UNION_E *)(val);				\
309								\
310	if (X##_e) X##_f0 |= _FP_IMPLBIT_E;			\
311	else X##_f0 &= ~(_FP_IMPLBIT_E);			\
312	_flo->bits.frac = X##_f0;				\
313	_flo->bits.exp  = X##_e;				\
314	_flo->bits.sign = X##_s;				\
315      }								\
316  } while (0)
317
318
319#define FP_UNPACK_E(X,val)		\
320  do {					\
321    FP_UNPACK_RAW_E(X,val);		\
322    _FP_UNPACK_CANONICAL(E,2,X);	\
323  } while (0)
324
325#define FP_UNPACK_EP(X,val)		\
326  do {					\
327    FP_UNPACK_RAW_EP(X,val);		\
328    _FP_UNPACK_CANONICAL(E,2,X);	\
329  } while (0)
330
331#define FP_PACK_E(val,X)		\
332  do {					\
333    _FP_PACK_CANONICAL(E,2,X);		\
334    FP_PACK_RAW_E(val,X);		\
335  } while (0)
336
337#define FP_PACK_EP(val,X)		\
338  do {					\
339    _FP_PACK_CANONICAL(E,2,X);		\
340    FP_PACK_RAW_EP(val,X);		\
341  } while (0)
342
343#define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN(E,2,X)
344#define FP_NEG_E(R,X)		_FP_NEG(E,2,R,X)
345#define FP_ADD_E(R,X,Y)		_FP_ADD(E,2,R,X,Y)
346#define FP_SUB_E(R,X,Y)		_FP_SUB(E,2,R,X,Y)
347#define FP_MUL_E(R,X,Y)		_FP_MUL(E,2,R,X,Y)
348#define FP_DIV_E(R,X,Y)		_FP_DIV(E,2,R,X,Y)
349#define FP_SQRT_E(R,X)		_FP_SQRT(E,2,R,X)
350
351/*
352 * Square root algorithms:
353 * We have just one right now, maybe Newton approximation
354 * should be added for those machines where division is fast.
355 * We optimize it by doing most of the calculations
356 * in one UWtype registers instead of two, although we don't
357 * have to.
358 */
359#define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
360  do {							\
361    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
362    _FP_FRAC_SRL_2(X, (_FP_WORKBITS));			\
363    while (q)						\
364      {							\
365        T##_f0 = S##_f0 + q;				\
366        if (T##_f0 <= X##_f0)				\
367          {						\
368            S##_f0 = T##_f0 + q;			\
369            X##_f0 -= T##_f0;				\
370            R##_f0 += q;				\
371          }						\
372        _FP_FRAC_SLL_1(X, 1);				\
373        q >>= 1;					\
374      }							\
375    _FP_FRAC_SLL_2(R, (_FP_WORKBITS));			\
376    if (X##_f0)						\
377      {							\
378	if (S##_f0 < X##_f0)				\
379	  R##_f0 |= _FP_WORK_ROUND;			\
380	R##_f0 |= _FP_WORK_STICKY;			\
381      }							\
382  } while (0)
383
384#define FP_CMP_E(r,X,Y,un)	_FP_CMP(E,2,r,X,Y,un)
385#define FP_CMP_EQ_E(r,X,Y)	_FP_CMP_EQ(E,2,r,X,Y)
386
387#define FP_TO_INT_E(r,X,rsz,rsg)	_FP_TO_INT(E,2,r,X,rsz,rsg)
388#define FP_TO_INT_ROUND_E(r,X,rsz,rsg)	_FP_TO_INT_ROUND(E,2,r,X,rsz,rsg)
389#define FP_FROM_INT_E(X,r,rs,rt)	_FP_FROM_INT(E,2,X,r,rs,rt)
390
391#define _FP_FRAC_HIGH_E(X)	(X##_f1)
392#define _FP_FRAC_HIGH_RAW_E(X)	(X##_f0)
393
394#endif /* not _FP_W_TYPE_SIZE < 64 */
395
396#endif /* __MATH_EMU_EXTENDED_H__ */
397