d03ab969 |
1 | /* -*-c-*- |
2 | * |
dd22938e |
3 | * $Id: mpx.h,v 1.14 2002/10/09 00:36:03 mdw Exp $ |
d03ab969 |
4 | * |
5 | * Low level multiprecision arithmetic |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: mpx.h,v $ |
dd22938e |
33 | * Revision 1.14 2002/10/09 00:36:03 mdw |
34 | * Fix bounds on workspace for Karatsuba operations. |
35 | * |
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36 | * Revision 1.13 2002/10/06 22:52:50 mdw |
37 | * Pile of changes for supporting two's complement properly. |
38 | * |
0f32e0f8 |
39 | * Revision 1.12 2001/04/03 19:36:05 mdw |
40 | * Add some simple bitwise operations so that Perl can use them. |
41 | * |
52cdaca9 |
42 | * Revision 1.11 2000/10/08 15:48:35 mdw |
43 | * Rename Karatsuba constants now that we have @gfx_kmul@ too. |
44 | * |
1a05a8ef |
45 | * Revision 1.10 2000/10/08 12:06:12 mdw |
46 | * Provide @mpx_ueq@ for rapidly testing equality of two integers. |
47 | * |
698bd937 |
48 | * Revision 1.9 1999/12/22 15:49:07 mdw |
49 | * New function for division by a small integer. |
50 | * |
5bf74dea |
51 | * Revision 1.8 1999/12/11 10:57:43 mdw |
52 | * Karatsuba squaring algorithm. |
53 | * |
652a6acf |
54 | * Revision 1.7 1999/12/11 01:51:28 mdw |
55 | * Change Karatsuba parameters slightly. |
56 | * |
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57 | * Revision 1.6 1999/12/10 23:23:51 mdw |
58 | * Karatsuba-Ofman multiplication algorithm. |
59 | * |
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60 | * Revision 1.5 1999/11/20 22:23:27 mdw |
61 | * Add function versions of some low-level macros with wider use. |
62 | * |
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63 | * Revision 1.4 1999/11/17 18:04:43 mdw |
64 | * Add two's complement support. Fix a bug in MPX_UMLAN. |
65 | * |
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66 | * Revision 1.3 1999/11/13 01:51:29 mdw |
67 | * Minor interface changes. Should be stable now. |
68 | * |
b9b1c853 |
69 | * Revision 1.2 1999/11/11 17:47:55 mdw |
70 | * Minor changes for different `mptypes.h' format. |
71 | * |
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72 | * Revision 1.1 1999/09/03 08:41:12 mdw |
73 | * Initial import. |
74 | * |
75 | */ |
76 | |
a86e33af |
77 | #ifndef CATACOMB_MPX_H |
78 | #define CATACOMB_MPX_H |
d03ab969 |
79 | |
80 | #ifdef __cplusplus |
81 | extern "C" { |
82 | #endif |
83 | |
84 | /*----- The idea ----------------------------------------------------------* |
85 | * |
86 | * This file provides functions and macros which work on vectors of words as |
87 | * unsigned multiprecision integers. The interface works in terms of base |
88 | * and limit pointers (i.e., a pointer to the start of a vector, and a |
89 | * pointer just past its end) rather than base pointer and length, because |
90 | * that requires more arithmetic and state to work on. |
91 | * |
92 | * The interfaces are slightly bizarre in other ways. Try to use the |
93 | * higher-level functions where you can: they're rather better designed to |
94 | * actually be friendly and useful. |
95 | */ |
96 | |
97 | /*----- Header files ------------------------------------------------------*/ |
98 | |
99 | #include <string.h> |
100 | |
a86e33af |
101 | #ifndef CATACOMB_MPW_H |
3c9ede17 |
102 | # include "mpw.h" |
d03ab969 |
103 | #endif |
104 | |
105 | /*----- General manipulation ----------------------------------------------*/ |
106 | |
107 | /* --- @MPX_SHRINK@ --- * |
108 | * |
109 | * Arguments: @const mpw *v@ = pointer to vector of words |
110 | * @const mpw *vl@ = (updated) current limit of vector |
111 | * |
112 | * Use: Shrinks down the limit of a multiprecision integer vector. |
113 | */ |
114 | |
115 | #define MPX_SHRINK(v, vl) do { \ |
3c9ede17 |
116 | const mpw *_vv = (v), *_vvl = (vl); \ |
117 | while (_vvl > _vv && !_vvl[-1]) \ |
118 | _vvl--; \ |
119 | (vl) = (mpw *)_vvl; \ |
d03ab969 |
120 | } while (0) |
121 | |
122 | /* --- @MPX_BITS@ --- * |
123 | * |
124 | * Arguments: @unsigned long b@ = result variable |
125 | * @const mpw *v@ = pointer to array of words |
126 | * @const mpw *vl@ = limit of vector (from @MPX_SHRINK@) |
127 | * |
128 | * Use: Calculates the number of bits in a multiprecision value. |
129 | */ |
130 | |
131 | #define MPX_BITS(b, v, vl) do { \ |
132 | const mpw *_v = (v), *_vl = (vl); \ |
3c9ede17 |
133 | MPX_SHRINK(_v, _vl); \ |
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134 | if (_v == _vl) \ |
135 | (b) = 0; \ |
136 | else { \ |
137 | unsigned long _b = MPW_BITS * (_vl - _v - 1) + 1; \ |
138 | mpw _w = _vl[-1]; \ |
139 | unsigned _k = MPW_BITS / 2; \ |
140 | while (_k) { \ |
141 | if (_w >> _k) { \ |
142 | _w >>= _k; \ |
143 | _b += _k; \ |
144 | } \ |
145 | _k >>= 1; \ |
146 | } \ |
147 | (b) = _b; \ |
148 | } \ |
149 | } while (0) |
150 | |
151 | /* --- @MPX_OCTETS@ --- * |
152 | * |
153 | * Arguments: @size_t o@ = result variable |
3c9ede17 |
154 | * @const mpw *v, *vl@ = pointer to array of words |
d03ab969 |
155 | * |
156 | * Use: Calculates the number of octets in a multiprecision value. |
157 | */ |
158 | |
3c9ede17 |
159 | #define MPX_OCTETS(o, v, vl) do { \ |
f09e814a |
160 | unsigned long _bb; \ |
161 | MPX_BITS(_bb, (v), (vl)); \ |
162 | (o) = (_bb + 7) >> 3; \ |
163 | } while (0) |
164 | |
165 | /* --- @MPX_OCTETS2C@ --- * |
166 | * |
167 | * Arguments: @size_t o@ = result variable |
168 | * @const mpw *v, *vl@ = pointer to array of words |
169 | * |
170 | * Use: Calculates the number of octets in a multiprecision value, if |
171 | * you represent it as two's complement. |
172 | */ |
173 | |
174 | #define MPX_OCTETS2C(o, v, vl) do { \ |
175 | unsigned long _bb; \ |
176 | MPX_BITS(_bb, (v), (vl)); \ |
177 | (o) = (_bb >> 3) + 1; \ |
d03ab969 |
178 | } while (0) |
179 | |
180 | /* --- @MPX_COPY@ --- * |
181 | * |
182 | * Arguments: @dv, dvl@ = destination vector base and limit |
183 | * @av, avl@ = source vector base and limit |
184 | * |
185 | * Use: Copies a multiprecision integer. |
186 | */ |
187 | |
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188 | #define MPX_COPY(dv, dvl, av, avl) do { \ |
189 | mpw *_dv = (dv), *_dvl = (dvl); \ |
190 | size_t _dn = _dvl - _dv; \ |
191 | const mpw *_av = (av), *_avl = (avl); \ |
192 | size_t _an = _avl - _av; \ |
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193 | if (_av == _dv) { \ |
194 | if (_dvl > _avl) \ |
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195 | memset(_dv, 0, MPWS(_dn - _an)); \ |
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196 | } else if (_an >= _dn) \ |
197 | memmove(_dv, _av, MPWS(_dn)); \ |
198 | else { \ |
199 | memmove(_dv, _av, MPWS(_an)); \ |
200 | memset(_dv + _an, 0, MPWS(_dn - _an)); \ |
201 | } \ |
202 | } while (0) |
203 | |
204 | /* --- @MPX_ZERO@ --- * |
205 | * |
206 | * Arguments: @v, vl@ = base and limit of vector to clear |
207 | * |
208 | * Use: Zeroes the area between the two vector pointers. |
209 | */ |
210 | |
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211 | #define MPX_ZERO(v, vl) do { \ |
d03ab969 |
212 | mpw *_v = (v), *_vl = (vl); \ |
3c9ede17 |
213 | if (_v < _vl) \ |
214 | memset(_v, 0, MPWS(_vl - _v)); \ |
d03ab969 |
215 | } while (0) |
216 | |
217 | /*----- Loading and storing -----------------------------------------------*/ |
218 | |
219 | /* --- @mpx_storel@ --- * |
220 | * |
221 | * Arguments: @const mpw *v, *vl@ = base and limit of source vector |
3c9ede17 |
222 | * @void *p@ = pointer to octet array |
d03ab969 |
223 | * @size_t sz@ = size of octet array |
224 | * |
225 | * Returns: --- |
226 | * |
227 | * Use: Stores an MP in an octet array, least significant octet |
228 | * first. High-end octets are silently discarded if there |
229 | * isn't enough space for them. |
230 | */ |
231 | |
232 | extern void mpx_storel(const mpw */*v*/, const mpw */*vl*/, |
3c9ede17 |
233 | void */*p*/, size_t /*sz*/); |
d03ab969 |
234 | |
235 | /* --- @mpx_loadl@ --- * |
236 | * |
237 | * Arguments: @mpw *v, *vl@ = base and limit of destination vector |
3c9ede17 |
238 | * @const void *p@ = pointer to octet array |
d03ab969 |
239 | * @size_t sz@ = size of octet array |
240 | * |
241 | * Returns: --- |
242 | * |
243 | * Use: Loads an MP in an octet array, least significant octet |
244 | * first. High-end octets are ignored if there isn't enough |
245 | * space for them. |
246 | */ |
247 | |
248 | extern void mpx_loadl(mpw */*v*/, mpw */*vl*/, |
3c9ede17 |
249 | const void */*p*/, size_t /*sz*/); |
d03ab969 |
250 | |
251 | /* --- @mpx_storeb@ --- * |
252 | * |
253 | * Arguments: @const mpw *v, *vl@ = base and limit of source vector |
3c9ede17 |
254 | * @void *p@ = pointer to octet array |
d03ab969 |
255 | * @size_t sz@ = size of octet array |
256 | * |
257 | * Returns: --- |
258 | * |
259 | * Use: Stores an MP in an octet array, most significant octet |
260 | * first. High-end octets are silently discarded if there |
261 | * isn't enough space for them. |
262 | */ |
263 | |
264 | extern void mpx_storeb(const mpw */*v*/, const mpw */*vl*/, |
3c9ede17 |
265 | void */*p*/, size_t /*sz*/); |
d03ab969 |
266 | |
267 | /* --- @mpx_loadb@ --- * |
268 | * |
269 | * Arguments: @mpw *v, *vl@ = base and limit of destination vector |
3c9ede17 |
270 | * @const void *p@ = pointer to octet array |
d03ab969 |
271 | * @size_t sz@ = size of octet array |
272 | * |
273 | * Returns: --- |
274 | * |
275 | * Use: Loads an MP in an octet array, most significant octet |
276 | * first. High-end octets are ignored if there isn't enough |
277 | * space for them. |
278 | */ |
279 | |
280 | extern void mpx_loadb(mpw */*v*/, mpw */*vl*/, |
3c9ede17 |
281 | const void */*p*/, size_t /*sz*/); |
d03ab969 |
282 | |
f09e814a |
283 | /* --- @mpx_storel2cn@ --- * |
284 | * |
285 | * Arguments: @const mpw *v, *vl@ = base and limit of source vector |
286 | * @void *pp@ = pointer to octet array |
287 | * @size_t sz@ = size of octet array |
288 | * |
289 | * Returns: --- |
290 | * |
291 | * Use: Stores a negative MP in an octet array, least significant |
292 | * octet first, as two's complement. High-end octets are |
293 | * silently discarded if there isn't enough space for them. |
294 | * This obviously makes the output bad. |
295 | */ |
296 | |
297 | extern void mpx_storel2cn(const mpw */*v*/, const mpw */*vl*/, |
298 | void */*p*/, size_t /*sz*/); |
299 | |
300 | /* --- @mpx_loadl2cn@ --- * |
301 | * |
302 | * Arguments: @mpw *v, *vl@ = base and limit of destination vector |
303 | * @const void *pp@ = pointer to octet array |
304 | * @size_t sz@ = size of octet array |
305 | * |
306 | * Returns: --- |
307 | * |
308 | * Use: Loads a negative MP in an octet array, least significant |
309 | * octet first, as two's complement. High-end octets are |
310 | * ignored if there isn't enough space for them. This probably |
311 | * means you made the wrong choice coming here. |
312 | */ |
313 | |
314 | extern void mpx_loadl2cn(mpw */*v*/, mpw */*vl*/, |
315 | const void */*p*/, size_t /*sz*/); |
316 | |
317 | /* --- @mpx_storeb2cn@ --- * |
318 | * |
319 | * Arguments: @const mpw *v, *vl@ = base and limit of source vector |
320 | * @void *pp@ = pointer to octet array |
321 | * @size_t sz@ = size of octet array |
322 | * |
323 | * Returns: --- |
324 | * |
325 | * Use: Stores a negative MP in an octet array, most significant |
326 | * octet first, as two's complement. High-end octets are |
327 | * silently discarded if there isn't enough space for them, |
328 | * which probably isn't what you meant. |
329 | */ |
330 | |
331 | extern void mpx_storeb2cn(const mpw */*v*/, const mpw */*vl*/, |
332 | void */*p*/, size_t /*sz*/); |
333 | |
334 | /* --- @mpx_loadb2cn@ --- * |
335 | * |
336 | * Arguments: @mpw *v, *vl@ = base and limit of destination vector |
337 | * @const void *pp@ = pointer to octet array |
338 | * @size_t sz@ = size of octet array |
339 | * |
340 | * Returns: --- |
341 | * |
342 | * Use: Loads a negative MP in an octet array, most significant octet |
343 | * first as two's complement. High-end octets are ignored if |
344 | * there isn't enough space for them. This probably means you |
345 | * chose this function wrongly. |
346 | */ |
347 | |
348 | extern void mpx_loadb2cn(mpw */*v*/, mpw */*vl*/, |
349 | const void */*p*/, size_t /*sz*/); |
350 | |
351 | |
d03ab969 |
352 | /*----- Logical shifting --------------------------------------------------*/ |
353 | |
354 | /* --- @mpx_lsl@ --- * |
355 | * |
356 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
357 | * @const mpw *av, *avl@ = source vector base and limit |
358 | * @size_t n@ = number of bit positions to shift by |
359 | * |
360 | * Returns: --- |
361 | * |
362 | * Use: Performs a logical shift left operation on an integer. |
363 | */ |
364 | |
365 | extern void mpx_lsl(mpw */*dv*/, mpw */*dvl*/, |
366 | const mpw */*av*/, const mpw */*avl*/, |
367 | size_t /*n*/); |
368 | |
369 | /* --- @mpx_lsr@ --- * |
370 | * |
371 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
372 | * @const mpw *av, *avl@ = source vector base and limit |
373 | * @size_t n@ = number of bit positions to shift by |
374 | * |
375 | * Returns: --- |
376 | * |
377 | * Use: Performs a logical shift right operation on an integer. |
378 | */ |
379 | |
380 | extern void mpx_lsr(mpw */*dv*/, mpw */*dvl*/, |
381 | const mpw */*av*/, const mpw */*avl*/, |
382 | size_t /*n*/); |
383 | |
0f32e0f8 |
384 | /*----- Bitwise operations ------------------------------------------------*/ |
385 | |
f09e814a |
386 | /* --- How to implement them --- * |
387 | * |
388 | * x: 0011 |
389 | * y: 0101 |
390 | */ |
391 | |
392 | #define MPX_B0000(x, y) (0u) |
393 | #define MPX_B0001(x, y) ((x) & (y)) |
394 | #define MPX_B0010(x, y) ((x) & ~(y)) |
395 | #define MPX_B0011(x, y) (x) |
396 | #define MPX_B0100(x, y) (~(x) & ~(y)) |
397 | #define MPX_B0101(x, y) (y) |
398 | #define MPX_B0110(x, y) ((x) ^ (y)) |
399 | #define MPX_B0111(x, y) ((x) | (y)) |
400 | #define MPX_B1000(x, y) (~((x) | (y))) |
401 | #define MPX_B1001(x, y) (~((x) ^ (y))) |
402 | #define MPX_B1010(x, y) (~(y)) |
403 | #define MPX_B1011(x, y) ((x) | ~(y)) |
404 | #define MPX_B1100(x, y) (~(x)) |
405 | #define MPX_B1101(x, y) (~(x) | (y)) |
406 | #define MPX_B1110(x, y) (~((x) & (y))) |
407 | #define MPX_B1111(x, y) (~0u) |
408 | |
409 | /* --- @mpx_bitop@ --- * |
0f32e0f8 |
410 | * |
411 | * Arguments: @mpw *dv, *dvl@ = destination vector |
412 | * @const mpw *av, *avl@ = first source vector |
413 | * @const mpw *bv, *bvl@ = second source vector |
414 | * |
415 | * Returns: --- |
416 | * |
f09e814a |
417 | * Use: Provide the dyadic boolean functions. The functions are |
418 | * named after the truth table they generate: |
419 | * |
420 | * a: 0011 |
421 | * b: 0101 |
422 | * @mpx_bitXXXX@ |
0f32e0f8 |
423 | */ |
424 | |
f09e814a |
425 | #define MPX_DOBIN(what) \ |
426 | what(0000) what(0001) what(0010) what(0011) \ |
427 | what(0100) what(0101) what(0110) what(0111) \ |
428 | what(1000) what(1001) what(1010) what(1011) \ |
429 | what(1100) what(1101) what(1110) what(1111) |
0f32e0f8 |
430 | |
f09e814a |
431 | #define MPX_BITDECL(string) \ |
432 | extern void mpx_bit##string(mpw */*dv*/, mpw */*dvl*/, \ |
433 | const mpw */*av*/, const mpw */*avl*/, \ |
434 | const mpw */*bv*/, const mpw */*bvl*/); |
435 | MPX_DOBIN(MPX_BITDECL) |
0f32e0f8 |
436 | |
f09e814a |
437 | /* --- @mpx_[n]and@, @mpx_[n]or@, @mpx_xor@ --- * |
438 | * |
439 | * Synonyms for the commonly-used functions above. |
440 | */ |
441 | |
442 | #define mpx_and mpx_bit0001 |
443 | #define mpx_or mpx_bit0111 |
444 | #define mpx_nand mpx_bit1110 |
445 | #define mpx_nor mpx_bit1000 |
446 | #define mpx_xor mpx_bit0110 |
447 | |
448 | /* --- @mpx_not@ --- * |
449 | * |
450 | * Arguments: @mpw *dv, *dvl@ = destination vector |
451 | * @const mpw *av, *avl@ = first source vector |
452 | * |
453 | * Returns: --- |
454 | * |
455 | * Use; Bitwise NOT. |
456 | */ |
0f32e0f8 |
457 | |
458 | extern void mpx_not(mpw */*dv*/, mpw */*dvl*/, |
459 | const mpw */*av*/, const mpw */*avl*/); |
460 | |
d03ab969 |
461 | /*----- Unsigned arithmetic -----------------------------------------------*/ |
462 | |
7c13f461 |
463 | /* --- @mpx_2c@ --- * |
464 | * |
465 | * Arguments: @mpw *dv, *dvl@ = destination vector |
466 | * @const mpw *v, *vl@ = source vector |
467 | * |
468 | * Returns: --- |
469 | * |
470 | * Use: Calculates the two's complement of @v@. |
471 | */ |
472 | |
473 | extern void mpx_2c(mpw */*dv*/, mpw */*dvl*/, |
474 | const mpw */*v*/, const mpw */*vl*/); |
475 | |
1a05a8ef |
476 | /* --- @mpx_ueq@ --- * |
477 | * |
478 | * Arguments: @const mpw *av, *avl@ = first argument vector base and limit |
479 | * @const mpw *bv, *bvl@ = second argument vector base and limit |
480 | * |
481 | * Returns: Nonzero if the two vectors are equal. |
482 | * |
483 | * Use: Performs an unsigned integer test for equality. |
484 | */ |
485 | |
486 | extern int mpx_ueq(const mpw */*av*/, const mpw */*avl*/, |
487 | const mpw */*bv*/, const mpw */*bvl*/); |
488 | |
d03ab969 |
489 | /* --- @mpx_ucmp@ --- * |
490 | * |
491 | * Arguments: @const mpw *av, *avl@ = first argument vector base and limit |
492 | * @const mpw *bv, *bvl@ = second argument vector base and limit |
493 | * |
494 | * Returns: Less than, equal to, or greater than zero depending on |
495 | * whether @a@ is less than, equal to or greater than @b@, |
496 | * respectively. |
497 | * |
498 | * Use: Performs an unsigned integer comparison. |
499 | */ |
500 | |
501 | #define MPX_UCMP(av, avl, op, dv, dvl) \ |
502 | (mpx_ucmp((av), (avl), (dv), (dvl)) op 0) |
503 | |
504 | extern int mpx_ucmp(const mpw */*av*/, const mpw */*avl*/, |
505 | const mpw */*bv*/, const mpw */*bvl*/); |
506 | |
507 | /* --- @mpx_uadd@ --- * |
508 | * |
509 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
510 | * @const mpw *av, *avl@ = first addend vector base and limit |
511 | * @const mpw *bv, *bvl@ = second addend vector base and limit |
512 | * |
513 | * Returns: --- |
514 | * |
515 | * Use: Performs unsigned integer addition. If the result overflows |
516 | * the destination vector, high-order bits are discarded. This |
517 | * means that two's complement addition happens more or less for |
518 | * free, although that's more a side-effect than anything else. |
519 | * The result vector may be equal to either or both source |
520 | * vectors, but may not otherwise overlap them. |
521 | */ |
522 | |
523 | extern void mpx_uadd(mpw */*dv*/, mpw */*dvl*/, |
524 | const mpw */*av*/, const mpw */*avl*/, |
525 | const mpw */*bv*/, const mpw */*bvl*/); |
526 | |
dd517851 |
527 | /* --- @mpx_uaddn@ --- * |
528 | * |
529 | * Arguments: @mpw *dv, *dvl@ = source and destination base and limit |
530 | * @mpw n@ = other addend |
3c9ede17 |
531 | * |
dd517851 |
532 | * Returns: --- |
3c9ede17 |
533 | * |
534 | * Use: Adds a small integer to a multiprecision number. |
535 | */ |
536 | |
537 | #define MPX_UADDN(dv, dvl, n) do { \ |
538 | mpw *_ddv = (dv), *_ddvl = (dvl); \ |
539 | mpw _c = (n); \ |
540 | \ |
541 | while (_c && _ddv < _ddvl) { \ |
542 | mpd _x = (mpd)*_ddv + (mpd)_c; \ |
543 | *_ddv++ = MPW(_x); \ |
544 | _c = _x >> MPW_BITS; \ |
545 | } \ |
546 | } while (0) |
547 | |
dd517851 |
548 | extern void mpx_uaddn(mpw */*dv*/, mpw */*dvl*/, mpw /*n*/); |
549 | |
d03ab969 |
550 | /* --- @mpx_usub@ --- * |
551 | * |
552 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
553 | * @const mpw *av, *avl@ = first argument vector base and limit |
554 | * @const mpw *bv, *bvl@ = second argument vector base and limit |
555 | * |
556 | * Returns: --- |
557 | * |
558 | * Use: Performs unsigned integer subtraction. If the result |
559 | * overflows the destination vector, high-order bits are |
560 | * discarded. This means that two's complement subtraction |
3c9ede17 |
561 | * happens more or less for free, although that's more a side- |
d03ab969 |
562 | * effect than anything else. The result vector may be equal to |
563 | * either or both source vectors, but may not otherwise overlap |
564 | * them. |
565 | */ |
566 | |
567 | extern void mpx_usub(mpw */*dv*/, mpw */*dvl*/, |
568 | const mpw */*av*/, const mpw */*avl*/, |
569 | const mpw */*bv*/, const mpw */*bvl*/); |
570 | |
dd517851 |
571 | /* --- @mpx_usubn@ --- * |
3c9ede17 |
572 | * |
dd517851 |
573 | * Arguments: @mpw *dv, *dvl@ = source and destination base and limit |
574 | * @n@ = subtrahend |
575 | * |
576 | * Returns: --- |
3c9ede17 |
577 | * |
578 | * Use: Subtracts a small integer from a multiprecision number. |
579 | */ |
580 | |
581 | #define MPX_USUBN(dv, dvl, n) do { \ |
582 | mpw *_ddv = (dv), *_ddvl = (dvl); \ |
583 | mpw _c = (n); \ |
584 | \ |
585 | while (_ddv < _ddvl) { \ |
586 | mpd _x = (mpd)*_ddv - (mpd)_c; \ |
587 | *_ddv++ = MPW(_x); \ |
588 | if (_x >> MPW_BITS) \ |
589 | _c = 1; \ |
590 | else \ |
591 | break; \ |
592 | } \ |
593 | } while (0) |
594 | |
dd517851 |
595 | extern void mpx_usubn(mpw */*dv*/, mpw */*dvl*/, mpw /*n*/); |
596 | |
3c9ede17 |
597 | /* --- @mpx_umul@ --- * |
598 | * |
599 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
600 | * @const mpw *av, *avl@ = multiplicand vector base and limit |
601 | * @const mpw *bv, *bvl@ = multiplier vector base and limit |
602 | * |
603 | * Returns: --- |
604 | * |
605 | * Use: Performs unsigned integer multiplication. If the result |
606 | * overflows the desination vector, high-order bits are |
607 | * discarded. The result vector may not overlap the argument |
608 | * vectors in any way. |
609 | */ |
610 | |
611 | extern void mpx_umul(mpw */*dv*/, mpw */*dvl*/, |
612 | const mpw */*av*/, const mpw */*avl*/, |
613 | const mpw */*bv*/, const mpw */*bvl*/); |
614 | |
dd517851 |
615 | /* --- @mpx_umuln@ --- * |
d03ab969 |
616 | * |
dd517851 |
617 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
618 | * @const mpw *av, *avl@ = multiplicand vector base and limit |
619 | * @mpw m@ = multiplier |
620 | * |
621 | * Returns: --- |
d03ab969 |
622 | * |
623 | * Use: Multiplies a multiprecision integer by a single-word value. |
624 | * The destination and source may be equal. The destination |
625 | * is completely cleared after use. |
626 | */ |
627 | |
628 | #define MPX_UMULN(dv, dvl, av, avl, m) do { \ |
629 | mpw *_dv = (dv), *_dvl = (dvl); \ |
630 | const mpw *_av = (av), *_avl = (avl); \ |
631 | mpw _c = 0; \ |
632 | mpd _m = (m); \ |
633 | \ |
634 | while (_av < _avl) { \ |
635 | mpd _x; \ |
636 | if (_dv >= _dvl) \ |
637 | break; \ |
3c9ede17 |
638 | _x = (mpd)_m * (mpd)*_av++ + _c; \ |
d03ab969 |
639 | *_dv++ = MPW(_x); \ |
640 | _c = _x >> MPW_BITS; \ |
641 | } \ |
642 | if (_dv < _dvl) { \ |
643 | *_dv++ = MPW(_c); \ |
644 | MPX_ZERO(_dv, _dvl); \ |
645 | } \ |
646 | } while (0) |
647 | |
dd517851 |
648 | extern void mpx_umuln(mpw */*dv*/, mpw */*dvl*/, |
649 | const mpw */*av*/, const mpw */*avl*/, mpw m); |
650 | |
651 | /* --- @mpx_umlan@ --- * |
d03ab969 |
652 | * |
dd517851 |
653 | * Arguments: @mpw *dv, *dvl@ = destination/accumulator base and limit |
654 | * @const mpw *av, *avl@ = multiplicand vector base and limit |
655 | * @mpw m@ = multiplier |
656 | * |
657 | * Returns: --- |
d03ab969 |
658 | * |
659 | * Use: Multiplies a multiprecision integer by a single-word value |
660 | * and adds the result to an accumulator. |
661 | */ |
662 | |
663 | #define MPX_UMLAN(dv, dvl, av, avl, m) do { \ |
664 | mpw *_dv = (dv), *_dvl = (dvl); \ |
665 | const mpw *_av = (av), *_avl = (avl); \ |
7c13f461 |
666 | mpw _cc = 0; \ |
d03ab969 |
667 | mpd _m = (m); \ |
668 | \ |
5bf74dea |
669 | while (_dv < _dvl && _av < _avl) { \ |
d03ab969 |
670 | mpd _x; \ |
7c13f461 |
671 | _x = (mpd)*_dv + (mpd)_m * (mpd)*_av++ + _cc; \ |
d03ab969 |
672 | *_dv++ = MPW(_x); \ |
7c13f461 |
673 | _cc = _x >> MPW_BITS; \ |
d03ab969 |
674 | } \ |
7c13f461 |
675 | MPX_UADDN(_dv, _dvl, _cc); \ |
d03ab969 |
676 | } while (0) |
677 | |
dd517851 |
678 | extern void mpx_umlan(mpw */*dv*/, mpw */*dvl*/, |
679 | const mpw */*av*/, const mpw */*avl*/, mpw m); |
680 | |
3c9ede17 |
681 | /* --- @mpx_usqr@ --- * |
d03ab969 |
682 | * |
683 | * Arguments: @mpw *dv, *dvl@ = destination vector base and limit |
3c9ede17 |
684 | * @const mpw *av, *av@ = source vector base and limit |
d03ab969 |
685 | * |
686 | * Returns: --- |
687 | * |
3c9ede17 |
688 | * Use: Performs unsigned integer squaring. The result vector must |
689 | * not overlap the source vector in any way. |
d03ab969 |
690 | */ |
691 | |
3c9ede17 |
692 | extern void mpx_usqr(mpw */*dv*/, mpw */*dvl*/, |
693 | const mpw */*av*/, const mpw */*avl*/); |
d03ab969 |
694 | |
5bf74dea |
695 | /* --- @mpx_udiv@ --- * |
696 | * |
697 | * Arguments: @mpw *qv, *qvl@ = quotient vector base and limit |
698 | * @mpw *rv, *rvl@ = dividend/remainder vector base and limit |
699 | * @const mpw *dv, *dvl@ = divisor vector base and limit |
700 | * @mpw *sv, *svl@ = scratch workspace |
701 | * |
702 | * Returns: --- |
703 | * |
704 | * Use: Performs unsigned integer division. If the result overflows |
705 | * the quotient vector, high-order bits are discarded. (Clearly |
706 | * the remainder vector can't overflow.) The various vectors |
707 | * may not overlap in any way. Yes, I know it's a bit odd |
708 | * requiring the dividend to be in the result position but it |
709 | * does make some sense really. The remainder must have |
710 | * headroom for at least two extra words. The scratch space |
711 | * must be at least one word larger than the divisor. |
712 | */ |
713 | |
714 | extern void mpx_udiv(mpw */*qv*/, mpw */*qvl*/, mpw */*rv*/, mpw */*rvl*/, |
715 | const mpw */*dv*/, const mpw */*dvl*/, |
716 | mpw */*sv*/, mpw */*svl*/); |
717 | |
698bd937 |
718 | /* --- @mpx_udivn@ --- * |
719 | * |
720 | * Arguments: @mpw *qv, *qvl@ = storage for the quotient (may overlap |
721 | * dividend) |
722 | * @const mpw *rv, *rvl@ = dividend |
723 | * @mpw d@ = single-precision divisor |
724 | * |
725 | * Returns: Remainder after divison. |
726 | * |
727 | * Use: Performs a single-precision division operation. |
728 | */ |
729 | |
730 | extern mpw mpx_udivn(mpw */*qv*/, mpw */*qvl*/, |
731 | const mpw */*rv*/, const mpw */*rvl*/, mpw /*d*/); |
732 | |
5bf74dea |
733 | /*----- Karatsuba multiplication algorithms -------------------------------*/ |
734 | |
52cdaca9 |
735 | /* --- @MPK_THRESH@ --- * |
5bf74dea |
736 | * |
737 | * This is the limiting length for using Karatsuba algorithms. It's best to |
738 | * use the simpler classical multiplication method on numbers smaller than |
dd22938e |
739 | * this. It is unsafe to make this constant less than four (i.e., the |
740 | * algorithms will fail). |
5bf74dea |
741 | */ |
742 | |
52cdaca9 |
743 | #define MPK_THRESH 16 |
5bf74dea |
744 | |
a86e33af |
745 | /* --- @mpx_kmul@ --- * |
746 | * |
747 | * Arguments: @mpw *dv, *dvl@ = pointer to destination buffer |
748 | * @const mpw *av, *avl@ = pointer to first argument |
749 | * @const mpw *bv, *bvl@ = pointer to second argument |
750 | * @mpw *sv, *svl@ = pointer to scratch workspace |
751 | * |
752 | * Returns: --- |
753 | * |
754 | * Use: Multiplies two multiprecision integers using Karatsuba's |
755 | * algorithm. This is rather faster than traditional long |
756 | * multiplication (e.g., @mpx_umul@) on large numbers, although |
757 | * more expensive on small ones. |
758 | * |
dd22938e |
759 | * The destination must be three times as large as the larger |
760 | * argument. The scratch space must be five times as large as |
761 | * the larger argument. |
a86e33af |
762 | */ |
763 | |
a86e33af |
764 | extern void mpx_kmul(mpw */*dv*/, mpw */*dvl*/, |
765 | const mpw */*av*/, const mpw */*avl*/, |
766 | const mpw */*bv*/, const mpw */*bvl*/, |
767 | mpw */*sv*/, mpw */*svl*/); |
768 | |
5bf74dea |
769 | /* --- @mpx_ksqr@ --- * |
d03ab969 |
770 | * |
5bf74dea |
771 | * Arguments: @mpw *dv, *dvl@ = pointer to destination buffer |
772 | * @const mpw *av, *avl@ = pointer to first argument |
773 | * @mpw *sv, *svl@ = pointer to scratch workspace |
d03ab969 |
774 | * |
775 | * Returns: --- |
776 | * |
5bf74dea |
777 | * Use: Squares a multiprecision integers using something similar to |
778 | * Karatsuba's multiplication algorithm. This is rather faster |
779 | * than traditional long multiplication (e.g., @mpx_umul@) on |
780 | * large numbers, although more expensive on small ones, and |
781 | * rather simpler than full-blown Karatsuba multiplication. |
782 | * |
dd22938e |
783 | * The destination must be three times as large as the larger |
784 | * argument. The scratch space must be five times as large as |
785 | * the larger argument. |
d03ab969 |
786 | */ |
787 | |
5bf74dea |
788 | extern void mpx_ksqr(mpw */*dv*/, mpw */*dvl*/, |
789 | const mpw */*av*/, const mpw */*avl*/, |
3c9ede17 |
790 | mpw */*sv*/, mpw */*svl*/); |
d03ab969 |
791 | |
792 | /*----- That's all, folks -------------------------------------------------*/ |
793 | |
794 | #ifdef __cplusplus |
795 | } |
796 | #endif |
797 | |
798 | #endif |