/* $OpenXM: OpenXM_contrib2/asir2000/engine/gf2n.c,v 1.1 1999/12/03 07:39:08 noro Exp $ */
#include "ca.h"
#include "base.h"
extern int lm_lazy;
GEN_UP2 current_mod_gf2n;
void setmod_gf2n(p)
P p;
{
if ( !current_mod_gf2n ) {
current_mod_gf2n = (GEN_UP2)MALLOC(sizeof(struct oGEN_UP2));
current_mod_gf2n->id = UP2_SPARSE; /* use sparse rep. by default */
}
ptoup2(p,¤t_mod_gf2n->dense);
ptoup2_sparse(p,¤t_mod_gf2n->sparse);
}
void getmod_gf2n(p)
UP2 *p;
{
if ( current_mod_gf2n )
*p = current_mod_gf2n->dense;
else
*p = 0;
}
void simpgf2n(n,r)
GF2N n;
GF2N *r;
{
UP2 rem;
if ( !n )
*r = 0;
else if ( NID(n) != N_GF2N )
*r = n;
else {
gen_simpup2(n->body,current_mod_gf2n,&rem);
MKGF2N(rem,*r);
}
}
void ptogf2n(q,l)
Obj q;
GF2N *l;
{
UP2 q1;
if ( !q || (OID(q)==O_N && NID(q)==N_GF2N) ) {
*l = (GF2N)q;
} else if ( (OID(q)==O_N && NID(q)==N_Q) || OID(q)==O_P ) {
ptoup2((P)q,&q1);
MKGF2N(q1,*l);
} else
error("ptogf2n : invalid argument");
}
void gf2ntop(q,l)
GF2N q;
P *l;
{
if ( !q )
*l = 0;
else
up2top(q->body,l);
}
void gf2ntovect(q,l)
GF2N q;
VECT *l;
{
if ( !q )
*l = 0;
else
up2tovect(q->body,l);
}
#define NZGF2N(a) ((a)&&(OID(a)==O_N)&&(NID(a)==N_GF2N))
void addgf2n(a,b,c)
GF2N a,b;
GF2N *c;
{
UP2 t,t1;
GF2N z;
ptogf2n((Obj)a,&z); a = z; ptogf2n((Obj)b,&z); b = z;
if ( !a )
*c = b;
else if ( !b )
*c = a;
else {
addup2(a->body,b->body,&t);
gen_simpup2(t,current_mod_gf2n,&t1);
MKGF2N(t1,*c);
}
}
void subgf2n(a,b,c)
GF2N a,b;
GF2N *c;
{
addgf2n(a,b,c);
}
void mulgf2n(a,b,c)
GF2N a,b;
GF2N *c;
{
UP2 t;
GF2N z;
ptogf2n((Obj)a,&z); a = z; ptogf2n((Obj)b,&z); b = z;
if ( !a || !b )
*c = 0;
else {
mulup2(a->body,b->body,&t);
#if 0
gen_simpup2(t,current_mod_gf2n,&t1);
MKGF2N(t1,*c);
#else
gen_simpup2_destructive(t,current_mod_gf2n);
if ( !t || !t->w )
*c = 0;
else
MKGF2N(t,*c);
#endif
}
}
void squaregf2n(a,c)
GF2N a;
GF2N *c;
{
UP2 t;
GF2N z;
ptogf2n((Obj)a,&z); a = z;
if ( !a )
*c = 0;
else {
squareup2(a->body,&t);
#if 0
gen_simpup2(t,current_mod_gf2n,&t1);
MKGF2N(t1,*c);
#else
gen_simpup2_destructive(t,current_mod_gf2n);
if ( !t || !t->w )
*c = 0;
else
MKGF2N(t,*c);
#endif
}
}
void divgf2n(a,b,c)
GF2N a,b;
GF2N *c;
{
UP2 t,i,s;
GF2N z;
ptogf2n((Obj)a,&z); a = z; ptogf2n((Obj)b,&z); b = z;
if ( !b )
error("divgf2n: division by 0");
else if ( !a )
*c = 0;
else {
gen_invup2(b->body,current_mod_gf2n,&i);
mulup2(a->body,i,&t);
gen_simpup2(t,current_mod_gf2n,&s);
MKGF2N(s,*c);
}
}
void invgf2n(b,c)
GF2N b;
GF2N *c;
{
UP2 i;
GF2N z;
ptogf2n((Obj)b,&z); b = z;
if ( !b )
error("divgf2n: division by 0");
else {
gen_invup2(b->body,current_mod_gf2n,&i);
MKGF2N(i,*c);
}
}
void chsgngf2n(a,c)
GF2N a,*c;
{
*c = a;
}
void pwrgf2n(a,b,c)
GF2N a;
Q b;
GF2N *c;
{
UP2 t;
GF2N r;
if ( !b ) {
MKGF2N(ONEUP2,*c);
} else if ( !a )
*c = 0;
else {
gen_pwrmodup2(a->body,b,current_mod_gf2n,&t);
MKGF2N(t,r);
if ( SGN(b) < 0 )
invgf2n(r,c);
else
*c = r;
}
}
int cmpgf2n(a,b)
GF2N a,b;
{
GF2N z;
ptogf2n((Obj)a,&z); a = z; ptogf2n((Obj)b,&z); b = z;
if ( !a )
if ( !b )
return 0;
else
return -1;
else if ( !b )
return 1;
else
return compup2(a->body,b->body);
}
void randomgf2n(r)
GF2N *r;
{
int i,w,d;
unsigned int *tb;
UP2 t;
if ( !current_mod_gf2n )
error("randomgf2n : current_mod_gf2n is not set");
w = current_mod_gf2n->dense->w;
d = degup2(current_mod_gf2n->dense);
NEWUP2(t,w);
for ( i = 0, tb = t->b; i < w; i++ )
tb[i] = mt_genrand();
tb[w-1] &= (1<<(d%BSH))-1;
for ( i = w-1; i >= 0 && !tb[i]; i-- );
if ( i < 0 )
*r = 0;
else {
t->w = i+1; MKGF2N(t,*r);
}
}