+++ /dev/null
-/* -*-c-*-
- *
- * $Id$
- *
- * Basic arithmetic on binary polynomials
- *
- * (c) 2004 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 "gf.h"
-
-/*----- Macros ------------------------------------------------------------*/
-
-#define MAX(x, y) ((x) >= (y) ? (x) : (y))
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @gf_add@ --- *
- *
- * Arguments: @mp *d@ = destination
- * @mp *a, *b@ = sources
- *
- * Returns: Result, @a@ added to @b@.
- */
-
-mp *gf_add(mp *d, mp *a, mp *b)
-{
- MP_DEST(d, MAX(MP_LEN(a), MP_LEN(b)), (a->f | b->f) & MP_BURN);
- gfx_add(d->v, d->vl, a->v, a->vl, b->v, b->vl);
- d->f = (a->f | b->f) & MP_BURN;
- MP_SHRINK(d);
- return (d);
-}
-
-/* --- @gf_mul@ --- *
- *
- * Arguments: @mp *d@ = destination
- * @mp *a, *b@ = sources
- *
- * Returns: Result, @a@ multiplied by @b@.
- */
-
-mp *gf_mul(mp *d, mp *a, mp *b)
-{
- a = MP_COPY(a);
- b = MP_COPY(b);
-
- if (MP_LEN(a) <= MPK_THRESH || MP_LEN(b) <= GFK_THRESH) {
- MP_DEST(d, MP_LEN(a) + MP_LEN(b), a->f | b->f | MP_UNDEF);
- gfx_mul(d->v, d->vl, a->v, a->vl, b->v, b->vl);
- } else {
- size_t m = MAX(MP_LEN(a), MP_LEN(b));
- mpw *s;
- MP_DEST(d, 2 * m, a->f | b->f | MP_UNDEF);
- s = mpalloc(d->a, 3 * m);
- gfx_kmul(d->v, d->vl, a->v, a->vl, b->v, b->vl, s, s + 3 * m);
- mpfree(d->a, s);
- }
-
- d->f = (a->f | b->f) & MP_BURN;
- MP_SHRINK(d);
- MP_DROP(a);
- MP_DROP(b);
- return (d);
-}
-
-/* --- @gf_sqr@ --- *
- *
- * Arguments: @mp *d@ = destination
- * @mp *a@ = source
- *
- * Returns: Result, @a@ squared.
- */
-
-mp *gf_sqr(mp *d, mp *a)
-{
- MP_COPY(a);
- MP_DEST(d, 2 * MP_LEN(a), a->f & MP_BURN);
- gfx_sqr(d->v, d->vl, a->v, a->vl);
- d->f = a->f & MP_BURN;
- MP_SHRINK(d);
- MP_DROP(a);
- return (d);
-}
-
-/* --- @gf_div@ --- *
- *
- * Arguments: @mp **qq, **rr@ = destination, quotient and remainder
- * @mp *a, *b@ = sources
- *
- * Use: Calculates the quotient and remainder when @a@ is divided by
- * @b@. The destinations @*qq@ and @*rr@ must be distinct.
- * Either of @qq@ or @rr@ may be null to indicate that the
- * result is irrelevant. (Discarding both results is silly.)
- * There is a performance advantage if @a == *rr@.
- */
-
-void gf_div(mp **qq, mp **rr, mp *a, mp *b)
- {
- mp *r = rr ? *rr : MP_NEW;
- mp *q = qq ? *qq : MP_NEW;
-
- /* --- Set the remainder up right --- */
-
- b = MP_COPY(b);
- a = MP_COPY(a);
- if (r)
- MP_DROP(r);
- r = a;
- MP_DEST(r, MP_LEN(b) + 2, a->f | b->f);
-
- /* --- Fix up the quotient too --- */
-
- r = MP_COPY(r);
- MP_DEST(q, MP_LEN(r), r->f | MP_UNDEF);
- MP_DROP(r);
-
- /* --- Perform the calculation --- */
-
- gfx_div(q->v, q->vl, r->v, r->vl, b->v, b->vl);
-
- /* --- Sort out the sign of the results --- *
- *
- * If the signs of the arguments differ, and the remainder is nonzero, I
- * must add one to the absolute value of the quotient and subtract the
- * remainder from @b@.
- */
-
- q->f = (r->f | b->f) & MP_BURN;
- r->f = (r->f | b->f) & MP_BURN;
-
- /* --- Store the return values --- */
-
- MP_DROP(b);
-
- if (!qq)
- MP_DROP(q);
- else {
- MP_SHRINK(q);
- *qq = q;
- }
-
- if (!rr)
- MP_DROP(r);
- else {
- MP_SHRINK(r);
- *rr = r;
- }
-}
-
-/* --- @gf_irreduciblep@ --- *
- *
- * Arguments: @mp *f@ = a polynomial
- *
- * Returns: Nonzero if the polynomial is irreducible; otherwise zero.
- */
-
-int gf_irreduciblep(mp *f)
-{
- unsigned long m;
- mp *u = MP_TWO;
- mp *v = MP_NEW;
-
- if (MP_ZEROP(f))
- return (0);
- else if (MP_LEN(f) == 1) {
- if (f->v[0] < 2) return (0);
- if (f->v[0] < 4) return (1);
- }
- m = (mp_bits(f) - 1)/2;
- while (m) {
- u = gf_sqr(u, u);
- gf_div(0, &u, u, f);
- v = gf_add(v, u, MP_TWO);
- gf_gcd(&v, 0, 0, v, f);
- if (!MP_EQ(v, MP_ONE)) break;
- m--;
- }
- MP_DROP(u);
- MP_DROP(v);
- return (!m);
-}
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-static int verify(const char *op, mp *expect, mp *result, mp *a, mp *b)
-{
- if (!MP_EQ(expect, result)) {
- fprintf(stderr, "\n*** %s failed", op);
- fputs("\n*** a = ", stderr); mp_writefile(a, stderr, 16);
- fputs("\n*** b = ", stderr); mp_writefile(b, stderr, 16);
- fputs("\n*** result = ", stderr); mp_writefile(result, stderr, 16);
- fputs("\n*** expect = ", stderr); mp_writefile(expect, stderr, 16);
- fputc('\n', stderr);
- return (0);
- }
- return (1);
-}
-
-#define RIG(name, op) \
- static int t##name(dstr *v) \
- { \
- mp *a = *(mp **)v[0].buf; \
- mp *b = *(mp **)v[1].buf; \
- mp *r = *(mp **)v[2].buf; \
- mp *c = op(MP_NEW, a, b); \
- int ok = verify(#name, r, c, a, b); \
- mp_drop(a); mp_drop(b); mp_drop(c); mp_drop(r); \
- assert(mparena_count(MPARENA_GLOBAL) == 0); \
- return (ok); \
- }
-
-RIG(add, gf_add)
-RIG(mul, gf_mul)
-RIG(exp, gf_exp)
-
-#undef RIG
-
-static int tsqr(dstr *v)
-{
- mp *a = *(mp **)v[0].buf;
- mp *r = *(mp **)v[1].buf;
- mp *c = MP_NEW;
- int ok = 1;
- c = gf_sqr(MP_NEW, a);
- ok &= verify("sqr", r, c, a, MP_ZERO);
- mp_drop(a); mp_drop(r); mp_drop(c);
- assert(mparena_count(MPARENA_GLOBAL) == 0);
- return (ok);
-}
-
-static int tdiv(dstr *v)
-{
- mp *a = *(mp **)v[0].buf;
- mp *b = *(mp **)v[1].buf;
- mp *q = *(mp **)v[2].buf;
- mp *r = *(mp **)v[3].buf;
- mp *c = MP_NEW, *d = MP_NEW;
- int ok = 1;
- gf_div(&c, &d, a, b);
- ok &= verify("div(quotient)", q, c, a, b);
- ok &= verify("div(remainder)", r, d, a, b);
- mp_drop(a); mp_drop(b); mp_drop(c); mp_drop(d); mp_drop(r); mp_drop(q);
- assert(mparena_count(MPARENA_GLOBAL) == 0);
- return (ok);
-}
-
-static int tirred(dstr *v)
-{
- mp *a = *(mp **)v[0].buf;
- int r = *(int *)v[1].buf;
- int c = gf_irreduciblep(a);
- int ok = 1;
- if (r != c) {
- ok = 0;
- fprintf(stderr, "\n*** irred failed");
- fputs("\n*** a = ", stderr); mp_writefile(a, stderr, 16);
- fprintf(stderr, "\n*** r = %d\n", r);
- fprintf(stderr, "*** c = %d\n", c);
- }
- mp_drop(a);
- assert(mparena_count(MPARENA_GLOBAL) == 0);
- return (ok);
-}
-
-static test_chunk tests[] = {
- { "add", tadd, { &type_mp, &type_mp, &type_mp, 0 } },
- { "mul", tmul, { &type_mp, &type_mp, &type_mp, 0 } },
- { "sqr", tsqr, { &type_mp, &type_mp, 0 } },
- { "div", tdiv, { &type_mp, &type_mp, &type_mp, &type_mp, 0 } },
- { "exp", texp, { &type_mp, &type_mp, &type_mp, 0 } },
- { "irred", tirred, { &type_mp, &type_int, 0 } },
- { 0, 0, { 0 } },
-};
-
-int main(int argc, char *argv[])
-{
- sub_init();
- test_run(argc, argv, tests, SRCDIR "/tests/gf");
- return (0);
-}
-
-#endif
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff