+++ /dev/null
-/* -*-c-*-
- *
- * $Id$
- *
- * Sqaring binary polynomials
- *
- * (c) 2000 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include "mpx.h"
-#include "gfx.h"
-#include "gfx-sqr-tab.h"
-
-/*----- Static variables --------------------------------------------------*/
-
-static const uint16 tab[256] = GFX_SQRTAB;
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @gfx_sqr@ --- *
- *
- * Arguments: @mpw *dv, *dvl@ = destination vector base and limit
- * @const mpw *av, *avl@ = argument vector base and limit
- *
- * Returns: ---
- *
- * Use: Performs squaring of binary polynomials.
- */
-
-void gfx_sqr(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl)
-{
- mpd a = 0, aa = 0;
- unsigned b = 0, bb = 0;
-
- /* --- Simple stuff --- */
-
- if (dv >= dvl)
- return;
- MPX_SHRINK(av, avl);
-
- /* --- The main algorithm --- *
- *
- * Our method depends on the fact that, in a field of characteristic 2, we
- * have that %$(a + b)^2 = a^2 + b^2$%. Thus, to square a polynomial, it's
- * sufficient just to put a zero bit between each of the bits of the
- * original argument. We use a precomputed table for this, and work on
- * entire octets at a time. Life is more complicated because we've got to
- * be careful of bizarre architectures which don't have words with a
- * multiple of 8 bits in them.
- */
-
- for (;;) {
-
- /* --- Input buffering --- */
-
- if (b < 8) {
- if (av >= avl)
- break;
- a |= *av++ << b;
- b += MPW_BITS;
- }
-
- /* --- Do the work in the middle --- */
-
- aa |= (mpd)(tab[U8(a)]) << bb;
- bb += 16;
- a >>= 8;
- b -= 8;
-
- /* --- Output buffering --- */
-
- if (bb >= MPW_BITS) {
- *dv++ = MPW(aa);
- if (dv >= dvl)
- return;
- aa >>= MPW_BITS;
- bb -= MPW_BITS;
- }
- }
-
- /* --- Flush the input buffer --- */
-
- if (b) for (;;) {
- aa |= (mpd)(tab[U8(a)]) << bb;
- bb += 16;
- if (bb > MPW_BITS) {
- *dv++ = MPW(aa);
- if (dv >= dvl)
- return;
- aa >>= MPW_BITS;
- bb -= MPW_BITS;
- }
- a >>= 8;
- if (b <= 8)
- break;
- else
- b -= 8;
- }
-
- /* --- Flush the output buffer --- */
-
- if (bb) for (;;) {
- *dv++ = MPW(aa);
- if (dv >= dvl)
- return;
- aa >>= MPW_BITS;
- if (bb <= MPW_BITS)
- break;
- else
- bb -= MPW_BITS;
- }
-
- /* --- Zero the rest of everything --- */
-
- MPX_ZERO(dv, dvl);
-}
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-#include <mLib/alloc.h>
-#include <mLib/dstr.h>
-#include <mLib/quis.h>
-#include <mLib/testrig.h>
-
-#define ALLOC(v, vl, sz) do { \
- size_t _sz = (sz); \
- mpw *_vv = xmalloc(MPWS(_sz)); \
- mpw *_vvl = _vv + _sz; \
- (v) = _vv; \
- (vl) = _vvl; \
-} while (0)
-
-#define LOAD(v, vl, d) do { \
- const dstr *_d = (d); \
- mpw *_v, *_vl; \
- ALLOC(_v, _vl, MPW_RQ(_d->len)); \
- mpx_loadb(_v, _vl, _d->buf, _d->len); \
- (v) = _v; \
- (vl) = _vl; \
-} while (0)
-
-#define MAX(x, y) ((x) > (y) ? (x) : (y))
-
-static void dumpmp(const char *msg, const mpw *v, const mpw *vl)
-{
- fputs(msg, stderr);
- MPX_SHRINK(v, vl);
- while (v < vl)
- fprintf(stderr, " %08lx", (unsigned long)*--vl);
- fputc('\n', stderr);
-}
-
-static int vsqr(dstr *v)
-{
- mpw *a, *al;
- mpw *b, *bl;
- mpw *d, *dl;
- int ok = 1;
-
- LOAD(a, al, &v[0]);
- LOAD(b, bl, &v[1]);
- ALLOC(d, dl, 2 * (al - a));
-
- gfx_sqr(d, dl, a, al);
- if (!mpx_ueq(d, dl, b, bl)) {
- fprintf(stderr, "\n*** vsqr failed\n");
- dumpmp(" a", a, al);
- dumpmp("expected", b, bl);
- dumpmp(" result", d, dl);
- ok = 0;
- }
-
- xfree(a); xfree(b); xfree(d);
- return (ok);
-}
-
-static test_chunk defs[] = {
- { "sqr", vsqr, { &type_hex, &type_hex, 0 } },
- { 0, 0, { 0 } }
-};
-
-int main(int argc, char *argv[])
-{
- test_run(argc, argv, defs, SRCDIR"/tests/gfx");
- return (0);
-}
-
-#endif
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff