File: [local] / OpenXM_contrib2 / asir2000 / engine / up_gf2n.c (download)
Revision 1.1.1.1 (vendor branch), Fri Dec 3 07:39:08 1999 UTC (24 years, 10 months ago) by noro
Branch: NORO
CVS Tags: RELEASE_20000124, RELEASE_1_1_2, ASIR2000 Changes since 1.1: +0 -0
lines
Imported asir2000 as OpenXM_contrib2/asir2000.
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/* $OpenXM: OpenXM_contrib2/asir2000/engine/up_gf2n.c,v 1.1.1.1 1999/12/03 07:39:08 noro Exp $ */
#include "ca.h"
#include <math.h>
extern int debug_up;
extern int up_lazy;
extern GEN_UP2 current_mod_gf2n;
void squarep_gf2n(vl,n1,nr)
VL vl;
P n1;
P *nr;
{
UP b1,br;
if ( !n1 )
*nr = 0;
else if ( OID(n1) == O_N )
mulp(vl,n1,n1,nr);
else {
ptoup(n1,&b1);
squareup_gf2n(b1,&br);
uptop(br,nr);
}
}
void squareup_gf2n(n1,nr)
UP n1;
UP *nr;
{
UP r;
GF2N *c1,*c;
int i,d1,d;
if ( !n1 )
*nr = 0;
else if ( !n1->d ) {
*nr = r = UPALLOC(0); r->d = 0;
squaregf2n((GF2N)n1->c[0],(GF2N *)(&r->c[0]));
} else {
d1 = n1->d;
d = 2*d1;
*nr = r = UPALLOC(d); r->d = d;
c1 = (GF2N *)n1->c; c = (GF2N *)r->c;
bzero((char *)c,(d+1)*sizeof(GF2N *));
for ( i = 0; i <= d1; i++ )
squaregf2n(c1[i],&c[2*i]);
}
}
/* x^(2^n) mod f */
void powermodup_gf2n(f,xp)
UP f;
UP *xp;
{
UP x,t,invf;
int k,n;
GF2N lm;
struct oEGT eg_sq,eg_rem,eg_mul,eg_inv,eg0,eg1,eg2;
n = degup2(current_mod_gf2n->dense);
MKGF2N(ONEUP2,lm);
x = UPALLOC(1); x->d = 1; x->c[1] = (Num)lm;
reverseup(f,f->d,&t);
invmodup(t,f->d,&invf);
for ( k = 0; k < n; k++ ) {
squareup_gf2n(x,&t);
rembymulup_special(t,f,invf,&x);
/* remup(t,f,&x); */
}
*xp = x;
}
/* g^d mod f */
void generic_powermodup_gf2n(g,f,d,xp)
UP g,f;
Q d;
UP *xp;
{
N e;
UP x,y,t,invf,s;
int k;
GF2N lm;
e = NM(d);
MKGF2N(ONEUP2,lm);
y = UPALLOC(0); y->d = 0; y->c[0] = (Num)lm;
remup(g,f,&x);
if ( !x ) {
*xp = !d ? y : 0;
return;
} else if ( !x->d ) {
pwrup(x,d,xp);
return;
}
reverseup(f,f->d,&t);
invmodup(t,f->d,&invf);
for ( k = n_bits(e)-1; k >= 0; k-- ) {
squareup_gf2n(y,&t);
rembymulup_special(t,f,invf,&s);
y = s;
if ( e->b[k/32] & (1<<(k%32)) ) {
mulup(y,x,&t);
remup(t,f,&s);
y = s;
}
}
*xp = y;
}
/* g+g^2+...+g^(2^(nd-1)) mod f; where e = deg(mod) */
void tracemodup_gf2n(g,f,d,xp)
UP g,f;
Q d;
UP *xp;
{
UP x,t,s,u,invf;
int en,i;
en = QTOS(d)*degup2(current_mod_gf2n->dense);
remup(g,f,&x);
if ( !x ) {
*xp = 0;
return;
}
reverseup(f,f->d,&t);
invmodup(t,f->d,&invf);
for ( i = 1, t = s = x; i < en; i++ ) {
squareup_gf2n(t,&u);
rembymulup_special(u,f,invf,&t);
addup(s,t,&u); s = u;
}
*xp = s;
}
void tracemodup_gf2n_slow(g,f,d,xp)
UP g,f;
Q d;
UP *xp;
{
UP x,t,s,u;
int en,i;
en = QTOS(d)*degup2(current_mod_gf2n->dense);
remup(g,f,&x);
if ( !x ) {
*xp = 0;
return;
}
for ( i = 1, t = s = x; i < en; i++ ) {
squareup_gf2n(t,&u);
remup(u,f,&t);
addup(s,t,&u); s = u;
}
*xp = s;
}
static struct oEGT eg_trace_tab,eg_trace_mul;
void tracemodup_gf2n_tab(g,f,d,xp)
UP g,f;
Q d;
UP *xp;
{
UP x0,x2,t,s,u;
int en,i;
UP *tab;
GF2N one;
struct oEGT eg1,eg2;
en = QTOS(d)*degup2(current_mod_gf2n->dense);
remup(g,f,&t); g = t;
if ( !g ) {
*xp = 0;
return;
}
MKGF2N(ONEUP2,one);
x0 = UPALLOC(0); x0->d = 0; x0->c[0] = (Num)one;
x2 = UPALLOC(2); x2->d = 2; x2->c[2] = (Num)one;
tab = (UP *)ALLOCA(en*sizeof(UP));
tab[0] = x0;
remup(x2,f,&tab[1]);
for ( i = 2; i < en; i++ ) {
mulup(tab[i-1],tab[1],&t); remup(t,f,&tab[i]);
}
for ( i = 1, t = s = g; i < en; i++ ) {
square_rem_tab_up_gf2n(t,tab,&u); t = u;
addup(s,t,&u); s = u;
}
*xp = s;
}
void square_rem_tab_up_gf2n(f,tab,rp)
UP f;
UP *tab;
UP *rp;
{
UP s,t,u,n;
Num *c;
int i,d;
n = UPALLOC(0); n->d = 0;
if ( !f )
*rp = 0;
else {
d = f->d; c = f->c;
up_lazy = 1;
for ( i = 0, s = 0; i <= d; i++ ) {
squaregf2n((GF2N)c[i],(GF2N *)(&n->c[0]));
mulup(tab[i],n,&t); addup(s,t,&u); s = u;
}
up_lazy = 0;
simpup(s,rp);
}
}
void powertabup_gf2n(f,xp,tab)
UP f;
UP xp;
UP *tab;
{
UP y,t,invf;
int i,d;
GF2N lm;
d = f->d;
MKGF2N(ONEUP2,lm);
y = UPALLOC(0); y->d = 0; y->c[0] = (Num)lm;
tab[0] = y;
tab[1] = xp;
reverseup(f,f->d,&t);
invmodup(t,f->d,&invf);
for ( i = 2; i < d; i++ ) {
if ( debug_up )
fprintf(stderr,".");
if ( !(i%2) )
squareup_gf2n(tab[i/2],&t);
else
kmulup(tab[i-1],xp,&t);
rembymulup_special(t,f,invf,&tab[i]);
/* remup(t,f,&tab[i]); */
}
}
void find_root_gf2n(f,r)
UP f;
GF2N *r;
{
UP g,ut,c,t,h,rem;
int n;
GF2N rn;
struct oEGT eg0,eg1,eg_trace;
n = degup2(current_mod_gf2n->dense);
g = f;
while ( g->d > 1 ) {
ut = UPALLOC(1); ut->c[0] = 0;
randomgf2n(&rn);
if ( !rn )
continue;
ut->c[1] = (Num)rn; ut->d = 1;
tracemodup_gf2n_tab(ut,f,ONE,&c);
gcdup(c,g,&h);
if ( h->d && h->d < g->d ) {
if ( 2*h->d > g->d ) {
qrup(g,h,&t,&rem); g = t;
if ( rem )
error("find_root_gf2n : cannot happen");
} else
g = h;
}
monicup(g,&t); g = t;
printf("deg(g)=%d\n",g->d);
}
divgf2n((GF2N)g->c[0],(GF2N)g->c[1],r);
}