1/* Software floating-point emulation.
2   Basic four-word fraction declaration and manipulation.
3   Copyright (C) 1997,1998,1999 Free Software Foundation, Inc.
4   This file is part of the GNU C Library.
5   Contributed by Richard Henderson (rth@cygnus.com),
6		  Jakub Jelinek (jj@ultra.linux.cz),
7		  David S. Miller (davem@redhat.com) and
8		  Peter Maydell (pmaydell@chiark.greenend.org.uk).
9
10   The GNU C Library is free software; you can redistribute it and/or
11   modify it under the terms of the GNU Library General Public License as
12   published by the Free Software Foundation; either version 2 of the
13   License, or (at your option) any later version.
14
15   The GNU C Library is distributed in the hope that it will be useful,
16   but WITHOUT ANY WARRANTY; without even the implied warranty of
17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18   Library General Public License for more details.
19
20   You should have received a copy of the GNU Library General Public
21   License along with the GNU C Library; see the file COPYING.LIB.  If
22   not, write to the Free Software Foundation, Inc.,
23   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
24
25#ifndef __MATH_EMU_OP_4_H__
26#define __MATH_EMU_OP_4_H__
27
28#define _FP_FRAC_DECL_4(X)	_FP_W_TYPE X##_f[4]
29#define _FP_FRAC_COPY_4(D,S)			\
30  (D##_f[0] = S##_f[0], D##_f[1] = S##_f[1],	\
31   D##_f[2] = S##_f[2], D##_f[3] = S##_f[3])
32#define _FP_FRAC_SET_4(X,I)	__FP_FRAC_SET_4(X, I)
33#define _FP_FRAC_HIGH_4(X)	(X##_f[3])
34#define _FP_FRAC_LOW_4(X)	(X##_f[0])
35#define _FP_FRAC_WORD_4(X,w)	(X##_f[w])
36
37#define _FP_FRAC_SLL_4(X,N)						\
38  do {									\
39    _FP_I_TYPE _up, _down, _skip, _i;					\
40    _skip = (N) / _FP_W_TYPE_SIZE;					\
41    _up = (N) % _FP_W_TYPE_SIZE;					\
42    _down = _FP_W_TYPE_SIZE - _up;					\
43    if (!_up)								\
44      for (_i = 3; _i >= _skip; --_i)					\
45	X##_f[_i] = X##_f[_i-_skip];					\
46    else								\
47      {									\
48	for (_i = 3; _i > _skip; --_i)					\
49	  X##_f[_i] = X##_f[_i-_skip] << _up				\
50		      | X##_f[_i-_skip-1] >> _down;			\
51	X##_f[_i--] = X##_f[0] << _up; 					\
52      }									\
53    for (; _i >= 0; --_i)						\
54      X##_f[_i] = 0;							\
55  } while (0)
56
57/* This one was broken too */
58#define _FP_FRAC_SRL_4(X,N)						\
59  do {									\
60    _FP_I_TYPE _up, _down, _skip, _i;					\
61    _skip = (N) / _FP_W_TYPE_SIZE;					\
62    _down = (N) % _FP_W_TYPE_SIZE;					\
63    _up = _FP_W_TYPE_SIZE - _down;					\
64    if (!_down)								\
65      for (_i = 0; _i <= 3-_skip; ++_i)					\
66	X##_f[_i] = X##_f[_i+_skip];					\
67    else								\
68      {									\
69	for (_i = 0; _i < 3-_skip; ++_i)				\
70	  X##_f[_i] = X##_f[_i+_skip] >> _down				\
71		      | X##_f[_i+_skip+1] << _up;			\
72	X##_f[_i++] = X##_f[3] >> _down;				\
73      }									\
74    for (; _i < 4; ++_i)						\
75      X##_f[_i] = 0;							\
76  } while (0)
77
78
79/* Right shift with sticky-lsb.
80 * What this actually means is that we do a standard right-shift,
81 * but that if any of the bits that fall off the right hand side
82 * were one then we always set the LSbit.
83 */
84#define _FP_FRAC_SRS_4(X,N,size)					\
85  do {									\
86    _FP_I_TYPE _up, _down, _skip, _i;					\
87    _FP_W_TYPE _s;							\
88    _skip = (N) / _FP_W_TYPE_SIZE;					\
89    _down = (N) % _FP_W_TYPE_SIZE;					\
90    _up = _FP_W_TYPE_SIZE - _down;					\
91    for (_s = _i = 0; _i < _skip; ++_i)					\
92      _s |= X##_f[_i];							\
93    _s |= X##_f[_i] << _up;						\
94/* s is now != 0 if we want to set the LSbit */				\
95    if (!_down)								\
96      for (_i = 0; _i <= 3-_skip; ++_i)					\
97	X##_f[_i] = X##_f[_i+_skip];					\
98    else								\
99      {									\
100	for (_i = 0; _i < 3-_skip; ++_i)				\
101	  X##_f[_i] = X##_f[_i+_skip] >> _down				\
102		      | X##_f[_i+_skip+1] << _up;			\
103	X##_f[_i++] = X##_f[3] >> _down;				\
104      }									\
105    for (; _i < 4; ++_i)						\
106      X##_f[_i] = 0;							\
107    /* don't fix the LSB until the very end when we're sure f[0] is stable */	\
108    X##_f[0] |= (_s != 0);						\
109  } while (0)
110
111#define _FP_FRAC_ADD_4(R,X,Y)						\
112  __FP_FRAC_ADD_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0],		\
113		  X##_f[3], X##_f[2], X##_f[1], X##_f[0],		\
114		  Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])
115
116#define _FP_FRAC_SUB_4(R,X,Y)						\
117  __FP_FRAC_SUB_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0],		\
118		  X##_f[3], X##_f[2], X##_f[1], X##_f[0],		\
119		  Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])
120
121#define _FP_FRAC_DEC_4(X,Y)						\
122  __FP_FRAC_DEC_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0],		\
123		  Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])
124
125#define _FP_FRAC_ADDI_4(X,I)						\
126  __FP_FRAC_ADDI_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0], I)
127
128#define _FP_ZEROFRAC_4  0,0,0,0
129#define _FP_MINFRAC_4   0,0,0,1
130#define _FP_MAXFRAC_4	(~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0)
131
132#define _FP_FRAC_ZEROP_4(X)     ((X##_f[0] | X##_f[1] | X##_f[2] | X##_f[3]) == 0)
133#define _FP_FRAC_NEGP_4(X)      ((_FP_WS_TYPE)X##_f[3] < 0)
134#define _FP_FRAC_OVERP_4(fs,X)  (_FP_FRAC_HIGH_##fs(X) & _FP_OVERFLOW_##fs)
135#define _FP_FRAC_CLEAR_OVERP_4(fs,X)  (_FP_FRAC_HIGH_##fs(X) &= ~_FP_OVERFLOW_##fs)
136
137#define _FP_FRAC_EQ_4(X,Y)				\
138 (X##_f[0] == Y##_f[0] && X##_f[1] == Y##_f[1]		\
139  && X##_f[2] == Y##_f[2] && X##_f[3] == Y##_f[3])
140
141#define _FP_FRAC_GT_4(X,Y)				\
142 (X##_f[3] > Y##_f[3] ||				\
143  (X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] ||	\
144   (X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] ||	\
145    (X##_f[1] == Y##_f[1] && X##_f[0] > Y##_f[0])	\
146   ))							\
147  ))							\
148 )
149
150#define _FP_FRAC_GE_4(X,Y)				\
151 (X##_f[3] > Y##_f[3] ||				\
152  (X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] ||	\
153   (X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] ||	\
154    (X##_f[1] == Y##_f[1] && X##_f[0] >= Y##_f[0])	\
155   ))							\
156  ))							\
157 )
158
159
160#define _FP_FRAC_CLZ_4(R,X)		\
161  do {					\
162    if (X##_f[3])			\
163    {					\
164	__FP_CLZ(R,X##_f[3]);		\
165    }					\
166    else if (X##_f[2])			\
167    {					\
168	__FP_CLZ(R,X##_f[2]);		\
169	R += _FP_W_TYPE_SIZE;		\
170    }					\
171    else if (X##_f[1])			\
172    {					\
173	__FP_CLZ(R,X##_f[2]);		\
174	R += _FP_W_TYPE_SIZE*2;		\
175    }					\
176    else				\
177    {					\
178	__FP_CLZ(R,X##_f[0]);		\
179	R += _FP_W_TYPE_SIZE*3;		\
180    }					\
181  } while(0)
182
183
184#define _FP_UNPACK_RAW_4(fs, X, val)				\
185  do {								\
186    union _FP_UNION_##fs _flo; _flo.flt = (val);		\
187    X##_f[0] = _flo.bits.frac0;					\
188    X##_f[1] = _flo.bits.frac1;					\
189    X##_f[2] = _flo.bits.frac2;					\
190    X##_f[3] = _flo.bits.frac3;					\
191    X##_e  = _flo.bits.exp;					\
192    X##_s  = _flo.bits.sign;					\
193  } while (0)
194
195#define _FP_UNPACK_RAW_4_P(fs, X, val)				\
196  do {								\
197    union _FP_UNION_##fs *_flo =				\
198      (union _FP_UNION_##fs *)(val);				\
199								\
200    X##_f[0] = _flo->bits.frac0;				\
201    X##_f[1] = _flo->bits.frac1;				\
202    X##_f[2] = _flo->bits.frac2;				\
203    X##_f[3] = _flo->bits.frac3;				\
204    X##_e  = _flo->bits.exp;					\
205    X##_s  = _flo->bits.sign;					\
206  } while (0)
207
208#define _FP_PACK_RAW_4(fs, val, X)				\
209  do {								\
210    union _FP_UNION_##fs _flo;					\
211    _flo.bits.frac0 = X##_f[0];					\
212    _flo.bits.frac1 = X##_f[1];					\
213    _flo.bits.frac2 = X##_f[2];					\
214    _flo.bits.frac3 = X##_f[3];					\
215    _flo.bits.exp   = X##_e;					\
216    _flo.bits.sign  = X##_s;					\
217    (val) = _flo.flt;				   		\
218  } while (0)
219
220#define _FP_PACK_RAW_4_P(fs, val, X)				\
221  do {								\
222    union _FP_UNION_##fs *_flo =				\
223      (union _FP_UNION_##fs *)(val);				\
224								\
225    _flo->bits.frac0 = X##_f[0];				\
226    _flo->bits.frac1 = X##_f[1];				\
227    _flo->bits.frac2 = X##_f[2];				\
228    _flo->bits.frac3 = X##_f[3];				\
229    _flo->bits.exp   = X##_e;					\
230    _flo->bits.sign  = X##_s;					\
231  } while (0)
232
233/*
234 * Multiplication algorithms:
235 */
236
237/* Given a 1W * 1W => 2W primitive, do the extended multiplication.  */
238
239#define _FP_MUL_MEAT_4_wide(wfracbits, R, X, Y, doit)			    \
240  do {									    \
241    _FP_FRAC_DECL_8(_z); _FP_FRAC_DECL_2(_b); _FP_FRAC_DECL_2(_c);	    \
242    _FP_FRAC_DECL_2(_d); _FP_FRAC_DECL_2(_e); _FP_FRAC_DECL_2(_f);	    \
243									    \
244    doit(_FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0), X##_f[0], Y##_f[0]); \
245    doit(_b_f1, _b_f0, X##_f[0], Y##_f[1]);				    \
246    doit(_c_f1, _c_f0, X##_f[1], Y##_f[0]);				    \
247    doit(_d_f1, _d_f0, X##_f[1], Y##_f[1]);				    \
248    doit(_e_f1, _e_f0, X##_f[0], Y##_f[2]);				    \
249    doit(_f_f1, _f_f0, X##_f[2], Y##_f[0]);				    \
250    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),	    \
251		    _FP_FRAC_WORD_8(_z,1), 0,_b_f1,_b_f0,		    \
252		    0,0,_FP_FRAC_WORD_8(_z,1));				    \
253    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),	    \
254		    _FP_FRAC_WORD_8(_z,1), 0,_c_f1,_c_f0,		    \
255		    _FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),	    \
256		    _FP_FRAC_WORD_8(_z,1));				    \
257    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),	    \
258		    _FP_FRAC_WORD_8(_z,2), 0,_d_f1,_d_f0,		    \
259		    0,_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2));	    \
260    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),	    \
261		    _FP_FRAC_WORD_8(_z,2), 0,_e_f1,_e_f0,		    \
262		    _FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),	    \
263		    _FP_FRAC_WORD_8(_z,2));				    \
264    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),	    \
265		    _FP_FRAC_WORD_8(_z,2), 0,_f_f1,_f_f0,		    \
266		    _FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),	    \
267		    _FP_FRAC_WORD_8(_z,2));				    \
268    doit(_b_f1, _b_f0, X##_f[0], Y##_f[3]);				    \
269    doit(_c_f1, _c_f0, X##_f[3], Y##_f[0]);				    \
270    doit(_d_f1, _d_f0, X##_f[1], Y##_f[2]);				    \
271    doit(_e_f1, _e_f0, X##_f[2], Y##_f[1]);				    \
272    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
273		    _FP_FRAC_WORD_8(_z,3), 0,_b_f1,_b_f0,		    \
274		    0,_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3));	    \
275    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
276		    _FP_FRAC_WORD_8(_z,3), 0,_c_f1,_c_f0,		    \
277		    _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
278		    _FP_FRAC_WORD_8(_z,3));				    \
279    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
280		    _FP_FRAC_WORD_8(_z,3), 0,_d_f1,_d_f0,		    \
281		    _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
282		    _FP_FRAC_WORD_8(_z,3));				    \
283    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
284		    _FP_FRAC_WORD_8(_z,3), 0,_e_f1,_e_f0,		    \
285		    _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),	    \
286		    _FP_FRAC_WORD_8(_z,3));				    \
287    doit(_b_f1, _b_f0, X##_f[2], Y##_f[2]);				    \
288    doit(_c_f1, _c_f0, X##_f[1], Y##_f[3]);				    \
289    doit(_d_f1, _d_f0, X##_f[3], Y##_f[1]);				    \
290    doit(_e_f1, _e_f0, X##_f[2], Y##_f[3]);				    \
291    doit(_f_f1, _f_f0, X##_f[3], Y##_f[2]);				    \
292    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),	    \
293		    _FP_FRAC_WORD_8(_z,4), 0,_b_f1,_b_f0,		    \
294		    0,_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4));	    \
295    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),	    \
296		    _FP_FRAC_WORD_8(_z,4), 0,_c_f1,_c_f0,		    \
297		    _FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),	    \
298		    _FP_FRAC_WORD_8(_z,4));				    \
299    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),	    \
300		    _FP_FRAC_WORD_8(_z,4), 0,_d_f1,_d_f0,		    \
301		    _FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),	    \
302		    _FP_FRAC_WORD_8(_z,4));				    \
303    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),	    \
304		    _FP_FRAC_WORD_8(_z,5), 0,_e_f1,_e_f0,		    \
305		    0,_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5));	    \
306    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),	    \
307		    _FP_FRAC_WORD_8(_z,5), 0,_f_f1,_f_f0,		    \
308		    _FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),	    \
309		    _FP_FRAC_WORD_8(_z,5));				    \
310    doit(_b_f1, _b_f0, X##_f[3], Y##_f[3]);				    \
311    __FP_FRAC_ADD_2(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),	    \
312		    _b_f1,_b_f0,					    \
313		    _FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6));	    \
314									    \
315    /* Normalize since we know where the msb of the multiplicands	    \
316       were (bit B), we know that the msb of the of the product is	    \
317       at either 2B or 2B-1.  */					    \
318    _FP_FRAC_SRS_8(_z, wfracbits-1, 2*wfracbits);			    \
319    __FP_FRAC_SET_4(R, _FP_FRAC_WORD_8(_z,3), _FP_FRAC_WORD_8(_z,2),	    \
320		    _FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0));	    \
321  } while (0)
322
323#define _FP_MUL_MEAT_4_gmp(wfracbits, R, X, Y)				    \
324  do {									    \
325    _FP_FRAC_DECL_8(_z);						    \
326									    \
327    mpn_mul_n(_z_f, _x_f, _y_f, 4);					    \
328									    \
329    /* Normalize since we know where the msb of the multiplicands	    \
330       were (bit B), we know that the msb of the of the product is	    \
331       at either 2B or 2B-1.  */					    \
332    _FP_FRAC_SRS_8(_z, wfracbits-1, 2*wfracbits);	 		    \
333    __FP_FRAC_SET_4(R, _FP_FRAC_WORD_8(_z,3), _FP_FRAC_WORD_8(_z,2),	    \
334		    _FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0));	    \
335  } while (0)
336
337/*
338 * Helper utility for _FP_DIV_MEAT_4_udiv:
339 * pppp = m * nnn
340 */
341#define umul_ppppmnnn(p3,p2,p1,p0,m,n2,n1,n0)				    \
342  do {									    \
343    UWtype _t;								    \
344    umul_ppmm(p1,p0,m,n0);						    \
345    umul_ppmm(p2,_t,m,n1);						    \
346    __FP_FRAC_ADDI_2(p2,p1,_t);						    \
347    umul_ppmm(p3,_t,m,n2);						    \
348    __FP_FRAC_ADDI_2(p3,p2,_t);						    \
349  } while (0)
350
351/*
352 * Division algorithms:
353 */
354
355#define _FP_DIV_MEAT_4_udiv(fs, R, X, Y)				    \
356  do {									    \
357    int _i;								    \
358    _FP_FRAC_DECL_4(_n); _FP_FRAC_DECL_4(_m);				    \
359    _FP_FRAC_SET_4(_n, _FP_ZEROFRAC_4);					    \
360    if (_FP_FRAC_GT_4(X, Y))						    \
361      {									    \
362	_n_f[3] = X##_f[0] << (_FP_W_TYPE_SIZE - 1);			    \
363	_FP_FRAC_SRL_4(X, 1);						    \
364      }									    \
365    else								    \
366      R##_e--;								    \
367									    \
368    /* Normalize, i.e. make the most significant bit of the 		    \
369       denominator set. */						    \
370    _FP_FRAC_SLL_4(Y, _FP_WFRACXBITS_##fs);				    \
371									    \
372    for (_i = 3; ; _i--)						    \
373      {									    \
374        if (X##_f[3] == Y##_f[3])					    \
375          {								    \
376            /* This is a special case, not an optimization		    \
377               (X##_f[3]/Y##_f[3] would not fit into UWtype).		    \
378               As X## is guaranteed to be < Y,  R##_f[_i] can be either	    \
379               (UWtype)-1 or (UWtype)-2.  */				    \
380            R##_f[_i] = -1;						    \
381            if (!_i)							    \
382	      break;							    \
383            __FP_FRAC_SUB_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0],	    \
384			    Y##_f[2], Y##_f[1], Y##_f[0], 0,		    \
385			    X##_f[2], X##_f[1], X##_f[0], _n_f[_i]);	    \
386            _FP_FRAC_SUB_4(X, Y, X);					    \
387            if (X##_f[3] > Y##_f[3])					    \
388              {								    \
389                R##_f[_i] = -2;						    \
390                _FP_FRAC_ADD_4(X, Y, X);				    \
391              }								    \
392          }								    \
393        else								    \
394          {								    \
395            udiv_qrnnd(R##_f[_i], X##_f[3], X##_f[3], X##_f[2], Y##_f[3]);  \
396            umul_ppppmnnn(_m_f[3], _m_f[2], _m_f[1], _m_f[0],		    \
397			  R##_f[_i], Y##_f[2], Y##_f[1], Y##_f[0]);	    \
398            X##_f[2] = X##_f[1];					    \
399            X##_f[1] = X##_f[0];					    \
400            X##_f[0] = _n_f[_i];					    \
401            if (_FP_FRAC_GT_4(_m, X))					    \
402              {								    \
403                R##_f[_i]--;						    \
404                _FP_FRAC_ADD_4(X, Y, X);				    \
405                if (_FP_FRAC_GE_4(X, Y) && _FP_FRAC_GT_4(_m, X))	    \
406                  {							    \
407		    R##_f[_i]--;					    \
408		    _FP_FRAC_ADD_4(X, Y, X);				    \
409                  }							    \
410              }								    \
411            _FP_FRAC_DEC_4(X, _m);					    \
412            if (!_i)							    \
413	      {								    \
414		if (!_FP_FRAC_EQ_4(X, _m))				    \
415		  R##_f[0] |= _FP_WORK_STICKY;				    \
416		break;							    \
417	      }								    \
418          }								    \
419      }									    \
420  } while (0)
421
422
423/*
424 * Square root algorithms:
425 * We have just one right now, maybe Newton approximation
426 * should be added for those machines where division is fast.
427 */
428
429#define _FP_SQRT_MEAT_4(R, S, T, X, q)				\
430  do {								\
431    while (q)							\
432      {								\
433	T##_f[3] = S##_f[3] + q;				\
434	if (T##_f[3] <= X##_f[3])				\
435	  {							\
436	    S##_f[3] = T##_f[3] + q;				\
437	    X##_f[3] -= T##_f[3];				\
438	    R##_f[3] += q;					\
439	  }							\
440	_FP_FRAC_SLL_4(X, 1);					\
441	q >>= 1;						\
442      }								\
443    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
444    while (q)							\
445      {								\
446	T##_f[2] = S##_f[2] + q;				\
447	T##_f[3] = S##_f[3];					\
448	if (T##_f[3] < X##_f[3] || 				\
449	    (T##_f[3] == X##_f[3] && T##_f[2] <= X##_f[2]))	\
450	  {							\
451	    S##_f[2] = T##_f[2] + q;				\
452	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
453	    __FP_FRAC_DEC_2(X##_f[3], X##_f[2],			\
454			    T##_f[3], T##_f[2]);		\
455	    R##_f[2] += q;					\
456	  }							\
457	_FP_FRAC_SLL_4(X, 1);					\
458	q >>= 1;						\
459      }								\
460    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
461    while (q)							\
462      {								\
463	T##_f[1] = S##_f[1] + q;				\
464	T##_f[2] = S##_f[2];					\
465	T##_f[3] = S##_f[3];					\
466	if (T##_f[3] < X##_f[3] || 				\
467	    (T##_f[3] == X##_f[3] && (T##_f[2] < X##_f[2] ||	\
468	     (T##_f[2] == X##_f[2] && T##_f[1] <= X##_f[1]))))	\
469	  {							\
470	    S##_f[1] = T##_f[1] + q;				\
471	    S##_f[2] += (T##_f[1] > S##_f[1]);			\
472	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
473	    __FP_FRAC_DEC_3(X##_f[3], X##_f[2], X##_f[1],	\
474	    		    T##_f[3], T##_f[2], T##_f[1]);	\
475	    R##_f[1] += q;					\
476	  }							\
477	_FP_FRAC_SLL_4(X, 1);					\
478	q >>= 1;						\
479      }								\
480    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
481    while (q != _FP_WORK_ROUND)					\
482      {								\
483	T##_f[0] = S##_f[0] + q;				\
484	T##_f[1] = S##_f[1];					\
485	T##_f[2] = S##_f[2];					\
486	T##_f[3] = S##_f[3];					\
487	if (_FP_FRAC_GE_4(X,T))					\
488	  {							\
489	    S##_f[0] = T##_f[0] + q;				\
490	    S##_f[1] += (T##_f[0] > S##_f[0]);			\
491	    S##_f[2] += (T##_f[1] > S##_f[1]);			\
492	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
493	    _FP_FRAC_DEC_4(X, T);				\
494	    R##_f[0] += q;					\
495	  }							\
496	_FP_FRAC_SLL_4(X, 1);					\
497	q >>= 1;						\
498      }								\
499    if (!_FP_FRAC_ZEROP_4(X))					\
500      {								\
501	if (_FP_FRAC_GT_4(X,S))					\
502	  R##_f[0] |= _FP_WORK_ROUND;				\
503	R##_f[0] |= _FP_WORK_STICKY;				\
504      }								\
505  } while (0)
506
507
508/*
509 * Internals
510 */
511
512#define __FP_FRAC_SET_4(X,I3,I2,I1,I0)					\
513  (X##_f[3] = I3, X##_f[2] = I2, X##_f[1] = I1, X##_f[0] = I0)
514
515#ifndef __FP_FRAC_ADD_3
516#define __FP_FRAC_ADD_3(r2,r1,r0,x2,x1,x0,y2,y1,y0)		\
517  do {								\
518    int _c1, _c2;							\
519    r0 = x0 + y0;						\
520    _c1 = r0 < x0;						\
521    r1 = x1 + y1;						\
522    _c2 = r1 < x1;						\
523    r1 += _c1;							\
524    _c2 |= r1 < _c1;						\
525    r2 = x2 + y2 + _c2;						\
526  } while (0)
527#endif
528
529#ifndef __FP_FRAC_ADD_4
530#define __FP_FRAC_ADD_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)	\
531  do {								\
532    int _c1, _c2, _c3;						\
533    r0 = x0 + y0;						\
534    _c1 = r0 < x0;						\
535    r1 = x1 + y1;						\
536    _c2 = r1 < x1;						\
537    r1 += _c1;							\
538    _c2 |= r1 < _c1;						\
539    r2 = x2 + y2;						\
540    _c3 = r2 < x2;						\
541    r2 += _c2;							\
542    _c3 |= r2 < _c2;						\
543    r3 = x3 + y3 + _c3;						\
544  } while (0)
545#endif
546
547#ifndef __FP_FRAC_SUB_3
548#define __FP_FRAC_SUB_3(r2,r1,r0,x2,x1,x0,y2,y1,y0)		\
549  do {								\
550    int _c1, _c2;							\
551    r0 = x0 - y0;						\
552    _c1 = r0 > x0;						\
553    r1 = x1 - y1;						\
554    _c2 = r1 > x1;						\
555    r1 -= _c1;							\
556    _c2 |= r1 > _c1;						\
557    r2 = x2 - y2 - _c2;						\
558  } while (0)
559#endif
560
561#ifndef __FP_FRAC_SUB_4
562#define __FP_FRAC_SUB_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)	\
563  do {								\
564    int _c1, _c2, _c3;						\
565    r0 = x0 - y0;						\
566    _c1 = r0 > x0;						\
567    r1 = x1 - y1;						\
568    _c2 = r1 > x1;						\
569    r1 -= _c1;							\
570    _c2 |= r1 > _c1;						\
571    r2 = x2 - y2;						\
572    _c3 = r2 > x2;						\
573    r2 -= _c2;							\
574    _c3 |= r2 > _c2;						\
575    r3 = x3 - y3 - _c3;						\
576  } while (0)
577#endif
578
579#ifndef __FP_FRAC_DEC_3
580#define __FP_FRAC_DEC_3(x2,x1,x0,y2,y1,y0)				\
581  do {									\
582    UWtype _t0, _t1, _t2;						\
583    _t0 = x0, _t1 = x1, _t2 = x2;					\
584    __FP_FRAC_SUB_3 (x2, x1, x0, _t2, _t1, _t0, y2, y1, y0);		\
585  } while (0)
586#endif
587
588#ifndef __FP_FRAC_DEC_4
589#define __FP_FRAC_DEC_4(x3,x2,x1,x0,y3,y2,y1,y0)			\
590  do {									\
591    UWtype _t0, _t1, _t2, _t3;						\
592    _t0 = x0, _t1 = x1, _t2 = x2, _t3 = x3;				\
593    __FP_FRAC_SUB_4 (x3,x2,x1,x0,_t3,_t2,_t1,_t0, y3,y2,y1,y0);		\
594  } while (0)
595#endif
596
597#ifndef __FP_FRAC_ADDI_4
598#define __FP_FRAC_ADDI_4(x3,x2,x1,x0,i)					\
599  do {									\
600    UWtype _t;								\
601    _t = ((x0 += i) < i);						\
602    x1 += _t; _t = (x1 < _t);						\
603    x2 += _t; _t = (x2 < _t);						\
604    x3 += _t;								\
605  } while (0)
606#endif
607
608/* Convert FP values between word sizes. This appears to be more
609 * complicated than I'd have expected it to be, so these might be
610 * wrong... These macros are in any case somewhat bogus because they
611 * use information about what various FRAC_n variables look like
612 * internally [eg, that 2 word vars are X_f0 and x_f1]. But so do
613 * the ones in op-2.h and op-1.h.
614 */
615#define _FP_FRAC_CONV_1_4(dfs, sfs, D, S)				\
616   do {									\
617     if (S##_c != FP_CLS_NAN)						\
618       _FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs),	\
619			  _FP_WFRACBITS_##sfs);				\
620     else								\
621       _FP_FRAC_SRL_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs));	\
622     D##_f = S##_f[0];							\
623  } while (0)
624
625#define _FP_FRAC_CONV_2_4(dfs, sfs, D, S)				\
626   do {									\
627     if (S##_c != FP_CLS_NAN)						\
628       _FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs),	\
629		      _FP_WFRACBITS_##sfs);				\
630     else								\
631       _FP_FRAC_SRL_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs));	\
632     D##_f0 = S##_f[0];							\
633     D##_f1 = S##_f[1];							\
634  } while (0)
635
636/* Assembly/disassembly for converting to/from integral types.
637 * No shifting or overflow handled here.
638 */
639/* Put the FP value X into r, which is an integer of size rsize. */
640#define _FP_FRAC_ASSEMBLE_4(r, X, rsize)				\
641  do {									\
642    if (rsize <= _FP_W_TYPE_SIZE)					\
643      r = X##_f[0];							\
644    else if (rsize <= 2*_FP_W_TYPE_SIZE)				\
645    {									\
646      r = X##_f[1];							\
647      r <<= _FP_W_TYPE_SIZE;						\
648      r += X##_f[0];							\
649    }									\
650    else								\
651    {									\
652      /* I'm feeling lazy so we deal with int == 3words (implausible)*/	\
653      /* and int == 4words as a single case.			 */	\
654      r = X##_f[3];							\
655      r <<= _FP_W_TYPE_SIZE;						\
656      r += X##_f[2];							\
657      r <<= _FP_W_TYPE_SIZE;						\
658      r += X##_f[1];							\
659      r <<= _FP_W_TYPE_SIZE;						\
660      r += X##_f[0];							\
661    }									\
662  } while (0)
663
664/* "No disassemble Number Five!" */
665/* move an integer of size rsize into X's fractional part. We rely on
666 * the _f[] array consisting of words of size _FP_W_TYPE_SIZE to avoid
667 * having to mask the values we store into it.
668 */
669#define _FP_FRAC_DISASSEMBLE_4(X, r, rsize)				\
670  do {									\
671    X##_f[0] = r;							\
672    X##_f[1] = (rsize <= _FP_W_TYPE_SIZE ? 0 : r >> _FP_W_TYPE_SIZE);	\
673    X##_f[2] = (rsize <= 2*_FP_W_TYPE_SIZE ? 0 : r >> 2*_FP_W_TYPE_SIZE); \
674    X##_f[3] = (rsize <= 3*_FP_W_TYPE_SIZE ? 0 : r >> 3*_FP_W_TYPE_SIZE); \
675  } while (0)
676
677#define _FP_FRAC_CONV_4_1(dfs, sfs, D, S)				\
678   do {									\
679     D##_f[0] = S##_f;							\
680     D##_f[1] = D##_f[2] = D##_f[3] = 0;				\
681     _FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs));	\
682   } while (0)
683
684#define _FP_FRAC_CONV_4_2(dfs, sfs, D, S)				\
685   do {									\
686     D##_f[0] = S##_f0;							\
687     D##_f[1] = S##_f1;							\
688     D##_f[2] = D##_f[3] = 0;						\
689     _FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs));	\
690   } while (0)
691
692#endif
693