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Fix bit operations. Test them (a bit) better.
[u/mdw/catacomb] / mpx.c
CommitLineData
d03ab969 1/* -*-c-*-
2 *
75263f25 3 * $Id: mpx.c,v 1.13 2002/10/19 17:56:50 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.c,v $
75263f25 33 * Revision 1.13 2002/10/19 17:56:50 mdw
34 * Fix bit operations. Test them (a bit) better.
35 *
f09e814a 36 * Revision 1.12 2002/10/06 22:52:50 mdw
37 * Pile of changes for supporting two's complement properly.
38 *
0f32e0f8 39 * Revision 1.11 2001/04/03 19:36:05 mdw
40 * Add some simple bitwise operations so that Perl can use them.
41 *
1a05a8ef 42 * Revision 1.10 2000/10/08 12:06:12 mdw
43 * Provide @mpx_ueq@ for rapidly testing equality of two integers.
44 *
99b30c23 45 * Revision 1.9 2000/06/26 07:52:50 mdw
46 * Portability fix for the bug fix.
47 *
ce76ff16 48 * Revision 1.8 2000/06/25 12:59:02 mdw
49 * (mpx_udiv): Fix bug in quotient digit estimation.
50 *
698bd937 51 * Revision 1.7 1999/12/22 15:49:07 mdw
52 * New function for division by a small integer.
53 *
42684bdb 54 * Revision 1.6 1999/11/20 22:43:44 mdw
55 * Integrate testing for MPX routines.
56 *
dd517851 57 * Revision 1.5 1999/11/20 22:23:27 mdw
58 * Add function versions of some low-level macros with wider use.
59 *
f45a00c6 60 * Revision 1.4 1999/11/17 18:04:09 mdw
61 * Add two's-complement functionality. Improve mpx_udiv a little by
62 * performing the multiplication of the divisor by q with the subtraction
63 * from r.
64 *
501da53c 65 * Revision 1.3 1999/11/13 01:57:31 mdw
66 * Remove stray debugging code.
67 *
c8a2f9ef 68 * Revision 1.2 1999/11/13 01:50:59 mdw
69 * Multiprecision routines finished and tested.
70 *
d03ab969 71 * Revision 1.1 1999/09/03 08:41:12 mdw
72 * Initial import.
73 *
74 */
75
76/*----- Header files ------------------------------------------------------*/
77
c8a2f9ef 78#include <assert.h>
d03ab969 79#include <stdio.h>
80#include <stdlib.h>
81#include <string.h>
82
83#include <mLib/bits.h>
84
85#include "mptypes.h"
86#include "mpx.h"
75263f25 87#include "bitops.h"
d03ab969 88
89/*----- Loading and storing -----------------------------------------------*/
90
91/* --- @mpx_storel@ --- *
92 *
93 * Arguments: @const mpw *v, *vl@ = base and limit of source vector
c8a2f9ef 94 * @void *pp@ = pointer to octet array
d03ab969 95 * @size_t sz@ = size of octet array
96 *
97 * Returns: ---
98 *
99 * Use: Stores an MP in an octet array, least significant octet
100 * first. High-end octets are silently discarded if there
101 * isn't enough space for them.
102 */
103
c8a2f9ef 104void mpx_storel(const mpw *v, const mpw *vl, void *pp, size_t sz)
d03ab969 105{
106 mpw n, w = 0;
c8a2f9ef 107 octet *p = pp, *q = p + sz;
d03ab969 108 unsigned bits = 0;
109
110 while (p < q) {
111 if (bits < 8) {
112 if (v >= vl) {
113 *p++ = U8(w);
114 break;
115 }
116 n = *v++;
117 *p++ = U8(w | n << bits);
118 w = n >> (8 - bits);
119 bits += MPW_BITS - 8;
120 } else {
121 *p++ = U8(w);
122 w >>= 8;
123 bits -= 8;
124 }
125 }
126 memset(p, 0, q - p);
127}
128
129/* --- @mpx_loadl@ --- *
130 *
131 * Arguments: @mpw *v, *vl@ = base and limit of destination vector
c8a2f9ef 132 * @const void *pp@ = pointer to octet array
d03ab969 133 * @size_t sz@ = size of octet array
134 *
135 * Returns: ---
136 *
137 * Use: Loads an MP in an octet array, least significant octet
138 * first. High-end octets are ignored if there isn't enough
139 * space for them.
140 */
141
c8a2f9ef 142void mpx_loadl(mpw *v, mpw *vl, const void *pp, size_t sz)
d03ab969 143{
144 unsigned n;
c8a2f9ef 145 mpw w = 0;
146 const octet *p = pp, *q = p + sz;
d03ab969 147 unsigned bits = 0;
148
149 if (v >= vl)
150 return;
151 while (p < q) {
152 n = U8(*p++);
153 w |= n << bits;
154 bits += 8;
155 if (bits >= MPW_BITS) {
156 *v++ = MPW(w);
157 w = n >> (MPW_BITS - bits + 8);
158 bits -= MPW_BITS;
159 if (v >= vl)
160 return;
161 }
162 }
163 *v++ = w;
164 MPX_ZERO(v, vl);
165}
166
167/* --- @mpx_storeb@ --- *
168 *
169 * Arguments: @const mpw *v, *vl@ = base and limit of source vector
c8a2f9ef 170 * @void *pp@ = pointer to octet array
d03ab969 171 * @size_t sz@ = size of octet array
172 *
173 * Returns: ---
174 *
175 * Use: Stores an MP in an octet array, most significant octet
176 * first. High-end octets are silently discarded if there
177 * isn't enough space for them.
178 */
179
c8a2f9ef 180void mpx_storeb(const mpw *v, const mpw *vl, void *pp, size_t sz)
d03ab969 181{
182 mpw n, w = 0;
c8a2f9ef 183 octet *p = pp, *q = p + sz;
d03ab969 184 unsigned bits = 0;
185
186 while (q > p) {
187 if (bits < 8) {
188 if (v >= vl) {
189 *--q = U8(w);
190 break;
191 }
192 n = *v++;
193 *--q = U8(w | n << bits);
194 w = n >> (8 - bits);
195 bits += MPW_BITS - 8;
196 } else {
197 *--q = U8(w);
198 w >>= 8;
199 bits -= 8;
200 }
201 }
202 memset(p, 0, q - p);
203}
204
205/* --- @mpx_loadb@ --- *
206 *
207 * Arguments: @mpw *v, *vl@ = base and limit of destination vector
c8a2f9ef 208 * @const void *pp@ = pointer to octet array
d03ab969 209 * @size_t sz@ = size of octet array
210 *
211 * Returns: ---
212 *
213 * Use: Loads an MP in an octet array, most significant octet
214 * first. High-end octets are ignored if there isn't enough
215 * space for them.
216 */
217
c8a2f9ef 218void mpx_loadb(mpw *v, mpw *vl, const void *pp, size_t sz)
d03ab969 219{
220 unsigned n;
c8a2f9ef 221 mpw w = 0;
222 const octet *p = pp, *q = p + sz;
d03ab969 223 unsigned bits = 0;
224
225 if (v >= vl)
226 return;
227 while (q > p) {
228 n = U8(*--q);
229 w |= n << bits;
230 bits += 8;
231 if (bits >= MPW_BITS) {
232 *v++ = MPW(w);
233 w = n >> (MPW_BITS - bits + 8);
234 bits -= MPW_BITS;
235 if (v >= vl)
236 return;
237 }
238 }
239 *v++ = w;
240 MPX_ZERO(v, vl);
241}
242
f09e814a 243/* --- @mpx_storel2cn@ --- *
244 *
245 * Arguments: @const mpw *v, *vl@ = base and limit of source vector
246 * @void *pp@ = pointer to octet array
247 * @size_t sz@ = size of octet array
248 *
249 * Returns: ---
250 *
251 * Use: Stores a negative MP in an octet array, least significant
252 * octet first, as two's complement. High-end octets are
253 * silently discarded if there isn't enough space for them.
254 * This obviously makes the output bad.
255 */
256
257void mpx_storel2cn(const mpw *v, const mpw *vl, void *pp, size_t sz)
258{
259 unsigned c = 1;
260 unsigned b = 0;
261 mpw n, w = 0;
262 octet *p = pp, *q = p + sz;
263 unsigned bits = 0;
264
265 while (p < q) {
266 if (bits < 8) {
267 if (v >= vl) {
268 b = w;
269 break;
270 }
271 n = *v++;
272 b = w | n << bits;
273 w = n >> (8 - bits);
274 bits += MPW_BITS - 8;
275 } else {
276 b = w;
277 w >>= 8;
278 bits -= 8;
279 }
280 b = U8(~b + c);
281 c = !b;
282 *p++ = b;
283 }
284 while (p < q) {
285 b = U8(~b + c);
286 c = !b;
287 *p++ = b;
288 b = 0;
289 }
290}
291
292/* --- @mpx_loadl2cn@ --- *
293 *
294 * Arguments: @mpw *v, *vl@ = base and limit of destination vector
295 * @const void *pp@ = pointer to octet array
296 * @size_t sz@ = size of octet array
297 *
298 * Returns: ---
299 *
300 * Use: Loads a negative MP in an octet array, least significant
301 * octet first, as two's complement. High-end octets are
302 * ignored if there isn't enough space for them. This probably
303 * means you made the wrong choice coming here.
304 */
305
306void mpx_loadl2cn(mpw *v, mpw *vl, const void *pp, size_t sz)
307{
308 unsigned n;
309 unsigned c = 1;
310 mpw w = 0;
311 const octet *p = pp, *q = p + sz;
312 unsigned bits = 0;
313
314 if (v >= vl)
315 return;
316 while (p < q) {
317 n = U8(~(*p++) + c);
318 c = !n;
319 w |= n << bits;
320 bits += 8;
321 if (bits >= MPW_BITS) {
322 *v++ = MPW(w);
323 w = n >> (MPW_BITS - bits + 8);
324 bits -= MPW_BITS;
325 if (v >= vl)
326 return;
327 }
328 }
329 *v++ = w;
330 MPX_ZERO(v, vl);
331}
332
333/* --- @mpx_storeb2cn@ --- *
334 *
335 * Arguments: @const mpw *v, *vl@ = base and limit of source vector
336 * @void *pp@ = pointer to octet array
337 * @size_t sz@ = size of octet array
338 *
339 * Returns: ---
340 *
341 * Use: Stores a negative MP in an octet array, most significant
342 * octet first, as two's complement. High-end octets are
343 * silently discarded if there isn't enough space for them,
344 * which probably isn't what you meant.
345 */
346
347void mpx_storeb2cn(const mpw *v, const mpw *vl, void *pp, size_t sz)
348{
349 mpw n, w = 0;
350 unsigned b = 0;
351 unsigned c = 1;
352 octet *p = pp, *q = p + sz;
353 unsigned bits = 0;
354
355 while (q > p) {
356 if (bits < 8) {
357 if (v >= vl) {
358 b = w;
359 break;
360 }
361 n = *v++;
362 b = w | n << bits;
363 w = n >> (8 - bits);
364 bits += MPW_BITS - 8;
365 } else {
366 b = w;
367 w >>= 8;
368 bits -= 8;
369 }
370 b = U8(~b + c);
371 c = !b;
372 *--q = b;
373 }
374 while (q > p) {
375 b = ~b + c;
376 c = !(b & 0xff);
377 *--q = b;
378 b = 0;
379 }
380}
381
382/* --- @mpx_loadb2cn@ --- *
383 *
384 * Arguments: @mpw *v, *vl@ = base and limit of destination vector
385 * @const void *pp@ = pointer to octet array
386 * @size_t sz@ = size of octet array
387 *
388 * Returns: ---
389 *
390 * Use: Loads a negative MP in an octet array, most significant octet
391 * first as two's complement. High-end octets are ignored if
392 * there isn't enough space for them. This probably means you
393 * chose this function wrongly.
394 */
395
396void mpx_loadb2cn(mpw *v, mpw *vl, const void *pp, size_t sz)
397{
398 unsigned n;
399 unsigned c = 1;
400 mpw w = 0;
401 const octet *p = pp, *q = p + sz;
402 unsigned bits = 0;
403
404 if (v >= vl)
405 return;
406 while (q > p) {
407 n = U8(~(*--q) + c);
408 c = !n;
409 w |= n << bits;
410 bits += 8;
411 if (bits >= MPW_BITS) {
412 *v++ = MPW(w);
413 w = n >> (MPW_BITS - bits + 8);
414 bits -= MPW_BITS;
415 if (v >= vl)
416 return;
417 }
418 }
419 *v++ = w;
420 MPX_ZERO(v, vl);
421}
422
d03ab969 423/*----- Logical shifting --------------------------------------------------*/
424
425/* --- @mpx_lsl@ --- *
426 *
427 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
428 * @const mpw *av, *avl@ = source vector base and limit
429 * @size_t n@ = number of bit positions to shift by
430 *
431 * Returns: ---
432 *
433 * Use: Performs a logical shift left operation on an integer.
434 */
435
436void mpx_lsl(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, size_t n)
437{
438 size_t nw;
439 unsigned nb;
440
441 /* --- Trivial special case --- */
442
443 if (n == 0)
444 MPX_COPY(dv, dvl, av, avl);
445
446 /* --- Single bit shifting --- */
447
448 else if (n == 1) {
449 mpw w = 0;
450 while (av < avl) {
451 mpw t;
452 if (dv >= dvl)
453 goto done;
454 t = *av++;
455 *dv++ = MPW((t << 1) | w);
456 w = t >> (MPW_BITS - 1);
457 }
458 if (dv >= dvl)
459 goto done;
460 *dv++ = MPW(w);
461 MPX_ZERO(dv, dvl);
c8a2f9ef 462 goto done;
d03ab969 463 }
464
465 /* --- Break out word and bit shifts for more sophisticated work --- */
466
467 nw = n / MPW_BITS;
468 nb = n % MPW_BITS;
469
470 /* --- Handle a shift by a multiple of the word size --- */
471
472 if (nb == 0) {
473 MPX_COPY(dv + nw, dvl, av, avl);
474 memset(dv, 0, MPWS(nw));
475 }
476
c8a2f9ef 477 /* --- And finally the difficult case --- *
478 *
479 * This is a little convoluted, because I have to start from the end and
480 * work backwards to avoid overwriting the source, if they're both the same
481 * block of memory.
482 */
d03ab969 483
484 else {
485 mpw w;
486 size_t nr = MPW_BITS - nb;
c8a2f9ef 487 size_t dvn = dvl - dv;
488 size_t avn = avl - av;
d03ab969 489
c8a2f9ef 490 if (dvn <= nw) {
d03ab969 491 MPX_ZERO(dv, dvl);
492 goto done;
493 }
d03ab969 494
c8a2f9ef 495 if (dvn > avn + nw) {
496 size_t off = avn + nw + 1;
497 MPX_ZERO(dv + off, dvl);
498 dvl = dv + off;
499 w = 0;
500 } else {
501 avl = av + dvn - nw;
502 w = *--avl << nb;
d03ab969 503 }
504
c8a2f9ef 505 while (avl > av) {
506 mpw t = *--avl;
507 *--dvl = (t >> nr) | w;
508 w = t << nb;
d03ab969 509 }
c8a2f9ef 510
511 *--dvl = w;
512 MPX_ZERO(dv, dvl);
d03ab969 513 }
514
515done:;
516}
517
518/* --- @mpx_lsr@ --- *
519 *
520 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
521 * @const mpw *av, *avl@ = source vector base and limit
522 * @size_t n@ = number of bit positions to shift by
523 *
524 * Returns: ---
525 *
526 * Use: Performs a logical shift right operation on an integer.
527 */
528
529void mpx_lsr(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, size_t n)
530{
531 size_t nw;
532 unsigned nb;
533
534 /* --- Trivial special case --- */
535
536 if (n == 0)
537 MPX_COPY(dv, dvl, av, avl);
538
539 /* --- Single bit shifting --- */
540
541 else if (n == 1) {
542 mpw w = *av++ >> 1;
543 while (av < avl) {
544 mpw t;
545 if (dv >= dvl)
546 goto done;
547 t = *av++;
548 *dv++ = MPW((t << (MPW_BITS - 1)) | w);
549 w = t >> 1;
550 }
551 if (dv >= dvl)
552 goto done;
553 *dv++ = MPW(w);
554 MPX_ZERO(dv, dvl);
c8a2f9ef 555 goto done;
d03ab969 556 }
557
558 /* --- Break out word and bit shifts for more sophisticated work --- */
559
560 nw = n / MPW_BITS;
561 nb = n % MPW_BITS;
562
563 /* --- Handle a shift by a multiple of the word size --- */
564
565 if (nb == 0)
566 MPX_COPY(dv, dvl, av + nw, avl);
567
568 /* --- And finally the difficult case --- */
569
570 else {
571 mpw w;
572 size_t nr = MPW_BITS - nb;
573
574 av += nw;
575 w = *av++;
576 while (av < avl) {
577 mpw t;
578 if (dv >= dvl)
579 goto done;
580 t = *av++;
581 *dv++ = MPW((w >> nb) | (t << nr));
582 w = t;
583 }
584 if (dv < dvl) {
585 *dv++ = MPW(w >> nb);
586 MPX_ZERO(dv, dvl);
587 }
588 }
589
590done:;
591}
592
0f32e0f8 593/*----- Bitwise operations ------------------------------------------------*/
594
f09e814a 595/* --- @mpx_bitop@ --- *
0f32e0f8 596 *
597 * Arguments: @mpw *dv, *dvl@ = destination vector
598 * @const mpw *av, *avl@ = first source vector
599 * @const mpw *bv, *bvl@ = second source vector
600 *
601 * Returns: ---
602 *
f09e814a 603 * Use; Provides the dyadic boolean functions.
0f32e0f8 604 */
605
f09e814a 606#define MPX_BITBINOP(string) \
0f32e0f8 607 \
f09e814a 608void mpx_bit##string(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, \
609 const mpw *bv, const mpw *bvl) \
0f32e0f8 610{ \
611 MPX_SHRINK(av, avl); \
612 MPX_SHRINK(bv, bvl); \
613 \
614 while (dv < dvl) { \
615 mpw a, b; \
616 a = (av < avl) ? *av++ : 0; \
617 b = (bv < bvl) ? *bv++ : 0; \
75263f25 618 *dv++ = B##string(a, b); \
0f32e0f8 619 } \
620}
621
f09e814a 622MPX_DOBIN(MPX_BITBINOP)
0f32e0f8 623
624void mpx_not(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl)
625{
626 MPX_SHRINK(av, avl);
627
628 while (dv < dvl) {
629 mpw a;
630 a = (av < avl) ? *av++ : 0;
631 *dv++ = ~a;
632 }
633}
634
d03ab969 635/*----- Unsigned arithmetic -----------------------------------------------*/
636
f45a00c6 637/* --- @mpx_2c@ --- *
638 *
639 * Arguments: @mpw *dv, *dvl@ = destination vector
640 * @const mpw *v, *vl@ = source vector
641 *
642 * Returns: ---
643 *
644 * Use: Calculates the two's complement of @v@.
645 */
646
647void mpx_2c(mpw *dv, mpw *dvl, const mpw *v, const mpw *vl)
648{
649 mpw c = 0;
650 while (dv < dvl && v < vl)
651 *dv++ = c = MPW(~*v++);
652 if (dv < dvl) {
653 if (c > MPW_MAX / 2)
654 c = MPW(~0);
655 while (dv < dvl)
656 *dv++ = c;
657 }
658 MPX_UADDN(dv, dvl, 1);
659}
660
1a05a8ef 661/* --- @mpx_ueq@ --- *
662 *
663 * Arguments: @const mpw *av, *avl@ = first argument vector base and limit
664 * @const mpw *bv, *bvl@ = second argument vector base and limit
665 *
666 * Returns: Nonzero if the two vectors are equal.
667 *
668 * Use: Performs an unsigned integer test for equality.
669 */
670
671int mpx_ueq(const mpw *av, const mpw *avl, const mpw *bv, const mpw *bvl)
672{
673 MPX_SHRINK(av, avl);
674 MPX_SHRINK(bv, bvl);
675 if (avl - av != bvl - bv)
676 return (0);
677 while (av < avl) {
678 if (*av++ != *bv++)
679 return (0);
680 }
681 return (1);
682}
683
d03ab969 684/* --- @mpx_ucmp@ --- *
685 *
686 * Arguments: @const mpw *av, *avl@ = first argument vector base and limit
687 * @const mpw *bv, *bvl@ = second argument vector base and limit
688 *
689 * Returns: Less than, equal to, or greater than zero depending on
690 * whether @a@ is less than, equal to or greater than @b@,
691 * respectively.
692 *
693 * Use: Performs an unsigned integer comparison.
694 */
695
696int mpx_ucmp(const mpw *av, const mpw *avl, const mpw *bv, const mpw *bvl)
697{
698 MPX_SHRINK(av, avl);
699 MPX_SHRINK(bv, bvl);
700
701 if (avl - av > bvl - bv)
702 return (+1);
703 else if (avl - av < bvl - bv)
704 return (-1);
705 else while (avl > av) {
706 mpw a = *--avl, b = *--bvl;
707 if (a > b)
708 return (+1);
709 else if (a < b)
710 return (-1);
711 }
712 return (0);
713}
1a05a8ef 714
d03ab969 715/* --- @mpx_uadd@ --- *
716 *
717 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
718 * @const mpw *av, *avl@ = first addend vector base and limit
719 * @const mpw *bv, *bvl@ = second addend vector base and limit
720 *
721 * Returns: ---
722 *
723 * Use: Performs unsigned integer addition. If the result overflows
724 * the destination vector, high-order bits are discarded. This
725 * means that two's complement addition happens more or less for
726 * free, although that's more a side-effect than anything else.
727 * The result vector may be equal to either or both source
728 * vectors, but may not otherwise overlap them.
729 */
730
731void mpx_uadd(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl,
732 const mpw *bv, const mpw *bvl)
733{
734 mpw c = 0;
735
736 while (av < avl || bv < bvl) {
737 mpw a, b;
738 mpd x;
739 if (dv >= dvl)
740 return;
741 a = (av < avl) ? *av++ : 0;
742 b = (bv < bvl) ? *bv++ : 0;
743 x = (mpd)a + (mpd)b + c;
744 *dv++ = MPW(x);
745 c = x >> MPW_BITS;
746 }
747 if (dv < dvl) {
748 *dv++ = c;
749 MPX_ZERO(dv, dvl);
750 }
751}
752
dd517851 753/* --- @mpx_uaddn@ --- *
754 *
755 * Arguments: @mpw *dv, *dvl@ = source and destination base and limit
756 * @mpw n@ = other addend
757 *
758 * Returns: ---
759 *
760 * Use: Adds a small integer to a multiprecision number.
761 */
762
763void mpx_uaddn(mpw *dv, mpw *dvl, mpw n) { MPX_UADDN(dv, dvl, n); }
764
d03ab969 765/* --- @mpx_usub@ --- *
766 *
767 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
768 * @const mpw *av, *avl@ = first argument vector base and limit
769 * @const mpw *bv, *bvl@ = second argument vector base and limit
770 *
771 * Returns: ---
772 *
773 * Use: Performs unsigned integer subtraction. If the result
774 * overflows the destination vector, high-order bits are
775 * discarded. This means that two's complement subtraction
776 * happens more or less for free, althuogh that's more a side-
777 * effect than anything else. The result vector may be equal to
778 * either or both source vectors, but may not otherwise overlap
779 * them.
780 */
781
782void mpx_usub(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl,
783 const mpw *bv, const mpw *bvl)
784{
785 mpw c = 0;
786
787 while (av < avl || bv < bvl) {
788 mpw a, b;
789 mpd x;
790 if (dv >= dvl)
791 return;
792 a = (av < avl) ? *av++ : 0;
793 b = (bv < bvl) ? *bv++ : 0;
c8a2f9ef 794 x = (mpd)a - (mpd)b - c;
d03ab969 795 *dv++ = MPW(x);
c8a2f9ef 796 if (x >> MPW_BITS)
797 c = 1;
798 else
799 c = 0;
d03ab969 800 }
c8a2f9ef 801 if (c)
802 c = MPW_MAX;
d03ab969 803 while (dv < dvl)
c8a2f9ef 804 *dv++ = c;
d03ab969 805}
806
dd517851 807/* --- @mpx_usubn@ --- *
808 *
809 * Arguments: @mpw *dv, *dvl@ = source and destination base and limit
810 * @n@ = subtrahend
811 *
812 * Returns: ---
813 *
814 * Use: Subtracts a small integer from a multiprecision number.
815 */
816
817void mpx_usubn(mpw *dv, mpw *dvl, mpw n) { MPX_USUBN(dv, dvl, n); }
818
d03ab969 819/* --- @mpx_umul@ --- *
820 *
821 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
822 * @const mpw *av, *avl@ = multiplicand vector base and limit
823 * @const mpw *bv, *bvl@ = multiplier vector base and limit
824 *
825 * Returns: ---
826 *
827 * Use: Performs unsigned integer multiplication. If the result
828 * overflows the desination vector, high-order bits are
829 * discarded. The result vector may not overlap the argument
830 * vectors in any way.
831 */
832
833void mpx_umul(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl,
834 const mpw *bv, const mpw *bvl)
835{
836 /* --- This is probably worthwhile on a multiply --- */
837
838 MPX_SHRINK(av, avl);
839 MPX_SHRINK(bv, bvl);
840
841 /* --- Deal with a multiply by zero --- */
842
843 if (bv == bvl) {
c8a2f9ef 844 MPX_ZERO(dv, dvl);
d03ab969 845 return;
846 }
847
848 /* --- Do the initial multiply and initialize the accumulator --- */
849
850 MPX_UMULN(dv, dvl, av, avl, *bv++);
851
852 /* --- Do the remaining multiply/accumulates --- */
853
c8a2f9ef 854 while (dv < dvl && bv < bvl) {
d03ab969 855 mpw m = *bv++;
c8a2f9ef 856 mpw c = 0;
d03ab969 857 const mpw *avv = av;
858 mpw *dvv = ++dv;
859
860 while (avv < avl) {
861 mpd x;
862 if (dvv >= dvl)
863 goto next;
c8a2f9ef 864 x = (mpd)*dvv + (mpd)m * (mpd)*avv++ + c;
865 *dvv++ = MPW(x);
d03ab969 866 c = x >> MPW_BITS;
867 }
c8a2f9ef 868 MPX_UADDN(dvv, dvl, c);
d03ab969 869 next:;
870 }
871}
872
dd517851 873/* --- @mpx_umuln@ --- *
874 *
875 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
876 * @const mpw *av, *avl@ = multiplicand vector base and limit
877 * @mpw m@ = multiplier
878 *
879 * Returns: ---
880 *
881 * Use: Multiplies a multiprecision integer by a single-word value.
882 * The destination and source may be equal. The destination
883 * is completely cleared after use.
884 */
885
886void mpx_umuln(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, mpw m)
887{
888 MPX_UMULN(dv, dvl, av, avl, m);
889}
890
891/* --- @mpx_umlan@ --- *
892 *
893 * Arguments: @mpw *dv, *dvl@ = destination/accumulator base and limit
894 * @const mpw *av, *avl@ = multiplicand vector base and limit
895 * @mpw m@ = multiplier
896 *
897 * Returns: ---
898 *
899 * Use: Multiplies a multiprecision integer by a single-word value
900 * and adds the result to an accumulator.
901 */
902
903void mpx_umlan(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, mpw m)
904{
905 MPX_UMLAN(dv, dvl, av, avl, m);
906}
907
c8a2f9ef 908/* --- @mpx_usqr@ --- *
909 *
910 * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
911 * @const mpw *av, *av@ = source vector base and limit
912 *
913 * Returns: ---
914 *
915 * Use: Performs unsigned integer squaring. The result vector must
916 * not overlap the source vector in any way.
917 */
918
919void mpx_usqr(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl)
920{
921 MPX_ZERO(dv, dvl);
922
923 /* --- Main loop --- */
924
925 while (av < avl) {
926 const mpw *avv = av;
927 mpw *dvv = dv;
928 mpw a = *av;
929 mpd c;
930
931 /* --- Stop if I've run out of destination --- */
932
933 if (dvv >= dvl)
934 break;
935
936 /* --- Work out the square at this point in the proceedings --- */
937
938 {
c8a2f9ef 939 mpd x = (mpd)a * (mpd)a + *dvv;
940 *dvv++ = MPW(x);
941 c = MPW(x >> MPW_BITS);
942 }
943
944 /* --- Now fix up the rest of the vector upwards --- */
945
946 avv++;
947 while (dvv < dvl && avv < avl) {
c8a2f9ef 948 mpd x = (mpd)a * (mpd)*avv++;
949 mpd y = ((x << 1) & MPW_MAX) + c + *dvv;
950 c = (x >> (MPW_BITS - 1)) + (y >> MPW_BITS);
951 *dvv++ = MPW(y);
952 }
953 while (dvv < dvl && c) {
954 mpd x = c + *dvv;
955 *dvv++ = MPW(x);
956 c = x >> MPW_BITS;
957 }
958
959 /* --- Get ready for the next round --- */
960
961 av++;
962 dv += 2;
963 }
964}
965
d03ab969 966/* --- @mpx_udiv@ --- *
967 *
968 * Arguments: @mpw *qv, *qvl@ = quotient vector base and limit
969 * @mpw *rv, *rvl@ = dividend/remainder vector base and limit
970 * @const mpw *dv, *dvl@ = divisor vector base and limit
c8a2f9ef 971 * @mpw *sv, *svl@ = scratch workspace
d03ab969 972 *
973 * Returns: ---
974 *
975 * Use: Performs unsigned integer division. If the result overflows
976 * the quotient vector, high-order bits are discarded. (Clearly
977 * the remainder vector can't overflow.) The various vectors
978 * may not overlap in any way. Yes, I know it's a bit odd
979 * requiring the dividend to be in the result position but it
980 * does make some sense really. The remainder must have
c8a2f9ef 981 * headroom for at least two extra words. The scratch space
f45a00c6 982 * must be at least one word larger than the divisor.
d03ab969 983 */
984
985void mpx_udiv(mpw *qv, mpw *qvl, mpw *rv, mpw *rvl,
c8a2f9ef 986 const mpw *dv, const mpw *dvl,
987 mpw *sv, mpw *svl)
d03ab969 988{
d03ab969 989 unsigned norm = 0;
990 size_t scale;
991 mpw d, dd;
992
993 /* --- Initialize the quotient --- */
994
995 MPX_ZERO(qv, qvl);
996
c8a2f9ef 997 /* --- Perform some sanity checks --- */
998
999 MPX_SHRINK(dv, dvl);
1000 assert(((void)"division by zero in mpx_udiv", dv < dvl));
1001
d03ab969 1002 /* --- Normalize the divisor --- *
1003 *
1004 * The algorithm requires that the divisor be at least two digits long.
1005 * This is easy to fix.
1006 */
1007
c8a2f9ef 1008 {
1009 unsigned b;
d03ab969 1010
c8a2f9ef 1011 d = dvl[-1];
1012 for (b = MPW_BITS / 2; b; b >>= 1) {
1013 if (d < (MPW_MAX >> b)) {
1014 d <<= b;
1015 norm += b;
1016 }
1017 }
1018 if (dv + 1 == dvl)
1019 norm += MPW_BITS;
d03ab969 1020 }
d03ab969 1021
1022 /* --- Normalize the dividend/remainder to match --- */
1023
c8a2f9ef 1024 if (norm) {
c8a2f9ef 1025 mpx_lsl(rv, rvl, rv, rvl, norm);
f45a00c6 1026 mpx_lsl(sv, svl, dv, dvl, norm);
c8a2f9ef 1027 dv = sv;
f45a00c6 1028 dvl = svl;
c8a2f9ef 1029 MPX_SHRINK(dv, dvl);
1030 }
1031
d03ab969 1032 MPX_SHRINK(rv, rvl);
c8a2f9ef 1033 d = dvl[-1];
1034 dd = dvl[-2];
d03ab969 1035
1036 /* --- Work out the relative scales --- */
1037
1038 {
1039 size_t rvn = rvl - rv;
c8a2f9ef 1040 size_t dvn = dvl - dv;
d03ab969 1041
1042 /* --- If the divisor is clearly larger, notice this --- */
1043
1044 if (dvn > rvn) {
1045 mpx_lsr(rv, rvl, rv, rvl, norm);
1046 return;
1047 }
1048
1049 scale = rvn - dvn;
1050 }
1051
1052 /* --- Calculate the most significant quotient digit --- *
1053 *
1054 * Because the divisor has its top bit set, this can only happen once. The
1055 * pointer arithmetic is a little contorted, to make sure that the
1056 * behaviour is defined.
1057 */
1058
1059 if (MPX_UCMP(rv + scale, rvl, >=, dv, dvl)) {
1060 mpx_usub(rv + scale, rvl, rv + scale, rvl, dv, dvl);
1061 if (qvl - qv > scale)
1062 qv[scale] = 1;
1063 }
1064
1065 /* --- Now for the main loop --- */
1066
1067 {
c8a2f9ef 1068 mpw *rvv = rvl - 2;
d03ab969 1069
1070 while (scale) {
c8a2f9ef 1071 mpw q;
1072 mpd rh;
d03ab969 1073
1074 /* --- Get an estimate for the next quotient digit --- */
1075
c8a2f9ef 1076 mpw r = rvv[1];
1077 mpw rr = rvv[0];
1078 mpw rrr = *--rvv;
1079
1080 scale--;
1081 rh = ((mpd)r << MPW_BITS) | rr;
d03ab969 1082 if (r == d)
1083 q = MPW_MAX;
c8a2f9ef 1084 else
1085 q = MPW(rh / d);
d03ab969 1086
1087 /* --- Refine the estimate --- */
1088
1089 {
1090 mpd yh = (mpd)d * q;
ce76ff16 1091 mpd yy = (mpd)dd * q;
1092 mpw yl;
c8a2f9ef 1093
ce76ff16 1094 if (yy > MPW_MAX)
1095 yh += yy >> MPW_BITS;
1096 yl = MPW(yy);
c8a2f9ef 1097
1098 while (yh > rh || (yh == rh && yl > rrr)) {
1099 q--;
1100 yh -= d;
ce76ff16 1101 if (yl < dd)
1102 yh--;
99b30c23 1103 yl = MPW(yl - dd);
c8a2f9ef 1104 }
1105 }
1106
1107 /* --- Remove a chunk from the dividend --- */
1108
1109 {
1110 mpw *svv;
1111 const mpw *dvv;
f45a00c6 1112 mpw mc = 0, sc = 0;
c8a2f9ef 1113
f45a00c6 1114 /* --- Calculate the size of the chunk --- *
1115 *
1116 * This does the whole job of calculating @r >> scale - qd@.
1117 */
c8a2f9ef 1118
f45a00c6 1119 for (svv = rv + scale, dvv = dv;
1120 dvv < dvl && svv < rvl;
1121 svv++, dvv++) {
1122 mpd x = (mpd)*dvv * (mpd)q + mc;
1123 mc = x >> MPW_BITS;
1124 x = (mpd)*svv - MPW(x) - sc;
c8a2f9ef 1125 *svv = MPW(x);
f45a00c6 1126 if (x >> MPW_BITS)
1127 sc = 1;
1128 else
1129 sc = 0;
1130 }
1131
1132 if (svv < rvl) {
1133 mpd x = (mpd)*svv - mc - sc;
1134 *svv++ = MPW(x);
1135 if (x >> MPW_BITS)
1136 sc = MPW_MAX;
1137 else
1138 sc = 0;
1139 while (svv < rvl)
1140 *svv++ = sc;
c8a2f9ef 1141 }
c8a2f9ef 1142
f45a00c6 1143 /* --- Fix if the quotient was too large --- *
c8a2f9ef 1144 *
f45a00c6 1145 * This doesn't seem to happen very often.
c8a2f9ef 1146 */
1147
c8a2f9ef 1148 if (rvl[-1] > MPW_MAX / 2) {
1149 mpx_uadd(rv + scale, rvl, rv + scale, rvl, dv, dvl);
1150 q--;
1151 }
1152 }
1153
1154 /* --- Done for another iteration --- */
1155
1156 if (qvl - qv > scale)
1157 qv[scale] = q;
1158 r = rr;
1159 rr = rrr;
1160 }
1161 }
1162
1163 /* --- Now fiddle with unnormalizing and things --- */
1164
1165 mpx_lsr(rv, rvl, rv, rvl, norm);
d03ab969 1166}
1167
698bd937 1168/* --- @mpx_udivn@ --- *
1169 *
1170 * Arguments: @mpw *qv, *qvl@ = storage for the quotient (may overlap
1171 * dividend)
1172 * @const mpw *rv, *rvl@ = dividend
1173 * @mpw d@ = single-precision divisor
1174 *
1175 * Returns: Remainder after divison.
1176 *
1177 * Use: Performs a single-precision division operation.
1178 */
1179
1180mpw mpx_udivn(mpw *qv, mpw *qvl, const mpw *rv, const mpw *rvl, mpw d)
1181{
1182 size_t i;
1183 size_t ql = qvl - qv;
1184 mpd r = 0;
1185
1186 i = rvl - rv;
1187 while (i > 0) {
1188 i--;
1189 r = (r << MPW_BITS) | rv[i];
1190 if (i < ql)
1191 qv[i] = r / d;
1192 r %= d;
1193 }
1194 return (MPW(r));
1195}
1196
42684bdb 1197/*----- Test rig ----------------------------------------------------------*/
1198
1199#ifdef TEST_RIG
1200
1201#include <mLib/alloc.h>
1202#include <mLib/dstr.h>
1203#include <mLib/quis.h>
1204#include <mLib/testrig.h>
1205
1206#include "mpscan.h"
1207
1208#define ALLOC(v, vl, sz) do { \
1209 size_t _sz = (sz); \
1210 mpw *_vv = xmalloc(MPWS(_sz)); \
1211 mpw *_vvl = _vv + _sz; \
1212 (v) = _vv; \
1213 (vl) = _vvl; \
1214} while (0)
1215
1216#define LOAD(v, vl, d) do { \
1217 const dstr *_d = (d); \
1218 mpw *_v, *_vl; \
1219 ALLOC(_v, _vl, MPW_RQ(_d->len)); \
1220 mpx_loadb(_v, _vl, _d->buf, _d->len); \
1221 (v) = _v; \
1222 (vl) = _vl; \
1223} while (0)
1224
1225#define MAX(x, y) ((x) > (y) ? (x) : (y))
1226
1227static void dumpbits(const char *msg, const void *pp, size_t sz)
1228{
1229 const octet *p = pp;
1230 fputs(msg, stderr);
1231 for (; sz; sz--)
1232 fprintf(stderr, " %02x", *p++);
1233 fputc('\n', stderr);
1234}
1235
1236static void dumpmp(const char *msg, const mpw *v, const mpw *vl)
1237{
1238 fputs(msg, stderr);
1239 MPX_SHRINK(v, vl);
1240 while (v < vl)
1241 fprintf(stderr, " %08lx", (unsigned long)*--vl);
1242 fputc('\n', stderr);
1243}
1244
1245static int chkscan(const mpw *v, const mpw *vl,
1246 const void *pp, size_t sz, int step)
1247{
1248 mpscan mps;
1249 const octet *p = pp;
1250 unsigned bit = 0;
1251 int ok = 1;
1252
1253 mpscan_initx(&mps, v, vl);
1254 while (sz) {
1255 unsigned x = *p;
1256 int i;
1257 p += step;
1258 for (i = 0; i < 8 && MPSCAN_STEP(&mps); i++) {
1259 if (MPSCAN_BIT(&mps) != (x & 1)) {
1260 fprintf(stderr,
1261 "\n*** error, step %i, bit %u, expected %u, found %u\n",
1262 step, bit, x & 1, MPSCAN_BIT(&mps));
1263 ok = 0;
1264 }
1265 x >>= 1;
1266 bit++;
1267 }
1268 sz--;
1269 }
1270
1271 return (ok);
1272}
1273
1274static int loadstore(dstr *v)
1275{
1276 dstr d = DSTR_INIT;
1277 size_t sz = MPW_RQ(v->len) * 2, diff;
1278 mpw *m, *ml;
1279 int ok = 1;
1280
1281 dstr_ensure(&d, v->len);
1282 m = xmalloc(MPWS(sz));
1283
1284 for (diff = 0; diff < sz; diff += 5) {
1285 size_t oct;
1286
1287 ml = m + sz - diff;
1288
1289 mpx_loadl(m, ml, v->buf, v->len);
1290 if (!chkscan(m, ml, v->buf, v->len, +1))
1291 ok = 0;
1292 MPX_OCTETS(oct, m, ml);
1293 mpx_storel(m, ml, d.buf, d.sz);
1294 if (memcmp(d.buf, v->buf, oct) != 0) {
1295 dumpbits("\n*** storel failed", d.buf, d.sz);
1296 ok = 0;
1297 }
1298
1299 mpx_loadb(m, ml, v->buf, v->len);
1300 if (!chkscan(m, ml, v->buf + v->len - 1, v->len, -1))
1301 ok = 0;
1302 MPX_OCTETS(oct, m, ml);
1303 mpx_storeb(m, ml, d.buf, d.sz);
1304 if (memcmp(d.buf + d.sz - oct, v->buf + v->len - oct, oct) != 0) {
1305 dumpbits("\n*** storeb failed", d.buf, d.sz);
1306 ok = 0;
1307 }
1308 }
1309
1310 if (!ok)
1311 dumpbits("input data", v->buf, v->len);
1312
1313 free(m);
1314 dstr_destroy(&d);
1315 return (ok);
1316}
1317
f09e814a 1318static int twocl(dstr *v)
1319{
1320 dstr d = DSTR_INIT;
1321 mpw *m, *ml;
1322 size_t sz;
1323 int ok = 1;
1324
1325 sz = v[0].len; if (v[1].len > sz) sz = v[1].len;
1326 dstr_ensure(&d, sz);
1327
1328 sz = MPW_RQ(sz);
1329 m = xmalloc(MPWS(sz));
1330 ml = m + sz;
1331
1332 mpx_loadl(m, ml, v[0].buf, v[0].len);
1333 mpx_storel2cn(m, ml, d.buf, v[1].len);
1334 if (memcmp(d.buf, v[1].buf, v[1].len)) {
1335 dumpbits("\n*** storel2cn failed", d.buf, v[1].len);
1336 ok = 0;
1337 }
1338
1339 mpx_loadl2cn(m, ml, v[1].buf, v[1].len);
1340 mpx_storel(m, ml, d.buf, v[0].len);
1341 if (memcmp(d.buf, v[0].buf, v[0].len)) {
1342 dumpbits("\n*** loadl2cn failed", d.buf, v[0].len);
1343 ok = 0;
1344 }
1345
1346 if (!ok) {
1347 dumpbits("pos", v[0].buf, v[0].len);
1348 dumpbits("neg", v[1].buf, v[1].len);
1349 }
1350
1351 free(m);
1352 dstr_destroy(&d);
1353
1354 return (ok);
1355}
1356
1357static int twocb(dstr *v)
1358{
1359 dstr d = DSTR_INIT;
1360 mpw *m, *ml;
1361 size_t sz;
1362 int ok = 1;
1363
1364 sz = v[0].len; if (v[1].len > sz) sz = v[1].len;
1365 dstr_ensure(&d, sz);
1366
1367 sz = MPW_RQ(sz);
1368 m = xmalloc(MPWS(sz));
1369 ml = m + sz;
1370
1371 mpx_loadb(m, ml, v[0].buf, v[0].len);
1372 mpx_storeb2cn(m, ml, d.buf, v[1].len);
1373 if (memcmp(d.buf, v[1].buf, v[1].len)) {
1374 dumpbits("\n*** storeb2cn failed", d.buf, v[1].len);
1375 ok = 0;
1376 }
1377
1378 mpx_loadb2cn(m, ml, v[1].buf, v[1].len);
1379 mpx_storeb(m, ml, d.buf, v[0].len);
1380 if (memcmp(d.buf, v[0].buf, v[0].len)) {
1381 dumpbits("\n*** loadb2cn failed", d.buf, v[0].len);
1382 ok = 0;
1383 }
1384
1385 if (!ok) {
1386 dumpbits("pos", v[0].buf, v[0].len);
1387 dumpbits("neg", v[1].buf, v[1].len);
1388 }
1389
1390 free(m);
1391 dstr_destroy(&d);
1392
1393 return (ok);
1394}
1395
42684bdb 1396static int lsl(dstr *v)
1397{
1398 mpw *a, *al;
1399 int n = *(int *)v[1].buf;
1400 mpw *c, *cl;
1401 mpw *d, *dl;
1402 int ok = 1;
1403
1404 LOAD(a, al, &v[0]);
1405 LOAD(c, cl, &v[2]);
1406 ALLOC(d, dl, al - a + (n + MPW_BITS - 1) / MPW_BITS);
1407
1408 mpx_lsl(d, dl, a, al, n);
1a05a8ef 1409 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1410 fprintf(stderr, "\n*** lsl(%i) failed\n", n);
1411 dumpmp(" a", a, al);
1412 dumpmp("expected", c, cl);
1413 dumpmp(" result", d, dl);
1414 ok = 0;
1415 }
1416
1417 free(a); free(c); free(d);
1418 return (ok);
1419}
1420
1421static int lsr(dstr *v)
1422{
1423 mpw *a, *al;
1424 int n = *(int *)v[1].buf;
1425 mpw *c, *cl;
1426 mpw *d, *dl;
1427 int ok = 1;
1428
1429 LOAD(a, al, &v[0]);
1430 LOAD(c, cl, &v[2]);
1431 ALLOC(d, dl, al - a + (n + MPW_BITS - 1) / MPW_BITS + 1);
1432
1433 mpx_lsr(d, dl, a, al, n);
1a05a8ef 1434 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1435 fprintf(stderr, "\n*** lsr(%i) failed\n", n);
1436 dumpmp(" a", a, al);
1437 dumpmp("expected", c, cl);
1438 dumpmp(" result", d, dl);
1439 ok = 0;
1440 }
1441
1442 free(a); free(c); free(d);
1443 return (ok);
1444}
1445
1446static int uadd(dstr *v)
1447{
1448 mpw *a, *al;
1449 mpw *b, *bl;
1450 mpw *c, *cl;
1451 mpw *d, *dl;
1452 int ok = 1;
1453
1454 LOAD(a, al, &v[0]);
1455 LOAD(b, bl, &v[1]);
1456 LOAD(c, cl, &v[2]);
1457 ALLOC(d, dl, MAX(al - a, bl - b) + 1);
1458
1459 mpx_uadd(d, dl, a, al, b, bl);
1a05a8ef 1460 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1461 fprintf(stderr, "\n*** uadd failed\n");
1462 dumpmp(" a", a, al);
1463 dumpmp(" b", b, bl);
1464 dumpmp("expected", c, cl);
1465 dumpmp(" result", d, dl);
1466 ok = 0;
1467 }
1468
1469 free(a); free(b); free(c); free(d);
1470 return (ok);
1471}
1472
1473static int usub(dstr *v)
1474{
1475 mpw *a, *al;
1476 mpw *b, *bl;
1477 mpw *c, *cl;
1478 mpw *d, *dl;
1479 int ok = 1;
1480
1481 LOAD(a, al, &v[0]);
1482 LOAD(b, bl, &v[1]);
1483 LOAD(c, cl, &v[2]);
1484 ALLOC(d, dl, al - a);
1485
1486 mpx_usub(d, dl, a, al, b, bl);
1a05a8ef 1487 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1488 fprintf(stderr, "\n*** usub failed\n");
1489 dumpmp(" a", a, al);
1490 dumpmp(" b", b, bl);
1491 dumpmp("expected", c, cl);
1492 dumpmp(" result", d, dl);
1493 ok = 0;
1494 }
1495
1496 free(a); free(b); free(c); free(d);
1497 return (ok);
1498}
1499
1500static int umul(dstr *v)
1501{
1502 mpw *a, *al;
1503 mpw *b, *bl;
1504 mpw *c, *cl;
1505 mpw *d, *dl;
1506 int ok = 1;
1507
1508 LOAD(a, al, &v[0]);
1509 LOAD(b, bl, &v[1]);
1510 LOAD(c, cl, &v[2]);
1511 ALLOC(d, dl, (al - a) + (bl - b));
1512
1513 mpx_umul(d, dl, a, al, b, bl);
1a05a8ef 1514 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1515 fprintf(stderr, "\n*** umul failed\n");
1516 dumpmp(" a", a, al);
1517 dumpmp(" b", b, bl);
1518 dumpmp("expected", c, cl);
1519 dumpmp(" result", d, dl);
1520 ok = 0;
1521 }
1522
1523 free(a); free(b); free(c); free(d);
1524 return (ok);
1525}
1526
1527static int usqr(dstr *v)
1528{
1529 mpw *a, *al;
1530 mpw *c, *cl;
1531 mpw *d, *dl;
1532 int ok = 1;
1533
1534 LOAD(a, al, &v[0]);
1535 LOAD(c, cl, &v[1]);
1536 ALLOC(d, dl, 2 * (al - a));
1537
1538 mpx_usqr(d, dl, a, al);
1a05a8ef 1539 if (!mpx_ueq(d, dl, c, cl)) {
42684bdb 1540 fprintf(stderr, "\n*** usqr failed\n");
1541 dumpmp(" a", a, al);
1542 dumpmp("expected", c, cl);
1543 dumpmp(" result", d, dl);
1544 ok = 0;
1545 }
1546
1547 free(a); free(c); free(d);
1548 return (ok);
1549}
1550
1551static int udiv(dstr *v)
1552{
1553 mpw *a, *al;
1554 mpw *b, *bl;
1555 mpw *q, *ql;
1556 mpw *r, *rl;
1557 mpw *qq, *qql;
1558 mpw *s, *sl;
1559 int ok = 1;
1560
1561 ALLOC(a, al, MPW_RQ(v[0].len) + 2); mpx_loadb(a, al, v[0].buf, v[0].len);
1562 LOAD(b, bl, &v[1]);
1563 LOAD(q, ql, &v[2]);
1564 LOAD(r, rl, &v[3]);
1565 ALLOC(qq, qql, al - a);
1566 ALLOC(s, sl, (bl - b) + 1);
1567
1568 mpx_udiv(qq, qql, a, al, b, bl, s, sl);
1a05a8ef 1569 if (!mpx_ueq(qq, qql, q, ql) ||
1570 !mpx_ueq(a, al, r, rl)) {
42684bdb 1571 fprintf(stderr, "\n*** udiv failed\n");
1572 dumpmp(" divisor", b, bl);
1573 dumpmp("expect r", r, rl);
1574 dumpmp("result r", a, al);
1575 dumpmp("expect q", q, ql);
1576 dumpmp("result q", qq, qql);
1577 ok = 0;
1578 }
1579
1580 free(a); free(b); free(r); free(q); free(s); free(qq);
1581 return (ok);
1582}
1583
1584static test_chunk defs[] = {
1585 { "load-store", loadstore, { &type_hex, 0 } },
f09e814a 1586 { "2cl", twocl, { &type_hex, &type_hex, } },
1587 { "2cb", twocb, { &type_hex, &type_hex, } },
42684bdb 1588 { "lsl", lsl, { &type_hex, &type_int, &type_hex, 0 } },
1589 { "lsr", lsr, { &type_hex, &type_int, &type_hex, 0 } },
1590 { "uadd", uadd, { &type_hex, &type_hex, &type_hex, 0 } },
1591 { "usub", usub, { &type_hex, &type_hex, &type_hex, 0 } },
1592 { "umul", umul, { &type_hex, &type_hex, &type_hex, 0 } },
1593 { "usqr", usqr, { &type_hex, &type_hex, 0 } },
1594 { "udiv", udiv, { &type_hex, &type_hex, &type_hex, &type_hex, 0 } },
1595 { 0, 0, { 0 } }
1596};
1597
1598int main(int argc, char *argv[])
1599{
1600 test_run(argc, argv, defs, SRCDIR"/tests/mpx");
1601 return (0);
1602}
1603
42684bdb 1604#endif
1605
d03ab969 1606/*----- That's all, folks -------------------------------------------------*/
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)