openssl/crypto/bn/old/bn_wmul.c
1998-12-21 11:00:56 +00:00

181 lines
3.1 KiB
C

#include <stdio.h>
#include "bn_lcl.h"
#if 1
int bn_mull(BIGNUM *r,BIGNUM *a,BIGNUM *b, BN_CTX *ctx);
int bn_mull(r,a,b,ctx)
BIGNUM *r,*a,*b;
BN_CTX *ctx;
{
int top,i,j,k,al,bl;
BIGNUM *t;
#ifdef BN_COUNT
printf("bn_mull %d * %d\n",a->top,b->top);
#endif
bn_check_top(a);
bn_check_top(b);
bn_check_top(r);
al=a->top;
bl=b->top;
r->neg=a->neg^b->neg;
top=al+bl;
if ((al < 4) || (bl < 4))
{
if (bn_wexpand(r,top) == NULL) return(0);
r->top=top;
bn_mul_normal(r->d,a->d,al,b->d,bl);
goto end;
}
else if (al == bl) /* A good start, they are the same size */
goto symetric;
else
{
i=(al-bl);
if ((i == 1) && !BN_get_flags(b,BN_FLG_STATIC_DATA))
{
bn_wexpand(b,al);
b->d[bl]=0;
bl++;
goto symetric;
}
else if ((i == -1) && !BN_get_flags(a,BN_FLG_STATIC_DATA))
{
bn_wexpand(a,bl);
a->d[al]=0;
al++;
goto symetric;
}
}
/* asymetric and >= 4 */
if (bn_wexpand(r,top) == NULL) return(0);
r->top=top;
bn_mul_normal(r->d,a->d,al,b->d,bl);
if (0)
{
/* symetric and > 4 */
symetric:
if (al == 4)
{
if (bn_wexpand(r,al*2) == NULL) return(0);
r->top=top;
bn_mul_comba4(r->d,a->d,b->d);
goto end;
}
if (al == 8)
{
if (bn_wexpand(r,al*2) == NULL) return(0);
r->top=top;
bn_mul_comba8(r->d,a->d,b->d);
goto end;
}
if (al <= BN_MULL_NORMAL_SIZE)
{
if (bn_wexpand(r,al*2) == NULL) return(0);
r->top=top;
bn_mul_normal(r->d,a->d,al,b->d,bl);
goto end;
}
/* 16 or larger */
j=BN_num_bits_word((BN_ULONG)al);
j=1<<(j-1);
k=j+j;
t= &(ctx->bn[ctx->tos]);
if (al == j) /* exact multiple */
{
bn_wexpand(t,k*2);
bn_wexpand(r,k*2);
bn_mul_recursive(r->d,a->d,b->d,al,t->d);
}
else
{
bn_wexpand(a,k);
bn_wexpand(b,k);
bn_wexpand(t,k*4);
bn_wexpand(r,k*4);
for (i=a->top; i<k; i++)
a->d[i]=0;
for (i=b->top; i<k; i++)
b->d[i]=0;
bn_mul_part_recursive(r->d,a->d,b->d,al-j,j,t->d);
}
r->top=top;
}
end:
bn_fix_top(r);
return(1);
}
#endif
void bn_mul_normal(r,a,na,b,nb)
BN_ULONG *r,*a;
int na;
BN_ULONG *b;
int nb;
{
BN_ULONG *rr;
#ifdef BN_COUNT
printf(" bn_mul_normal %d * %d\n",na,nb);
#endif
if (na < nb)
{
int itmp;
BN_ULONG *ltmp;
itmp=na; na=nb; nb=itmp;
ltmp=a; a=b; b=ltmp;
}
rr= &(r[na]);
rr[0]=bn_mul_words(r,a,na,b[0]);
for (;;)
{
if (--nb <= 0) return;
rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]);
if (--nb <= 0) return;
rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]);
if (--nb <= 0) return;
rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]);
if (--nb <= 0) return;
rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]);
rr+=4;
r+=4;
b+=4;
}
}
#if 1
void bn_mul_low_normal(r,a,b,n)
BN_ULONG *r,*a,*b;
int n;
{
#ifdef BN_COUNT
printf(" bn_mul_low_normal %d * %d\n",n,n);
#endif
bn_mul_words(r,a,n,b[0]);
for (;;)
{
if (--n <= 0) return;
bn_mul_add_words(&(r[1]),a,n,b[1]);
if (--n <= 0) return;
bn_mul_add_words(&(r[2]),a,n,b[2]);
if (--n <= 0) return;
bn_mul_add_words(&(r[3]),a,n,b[3]);
if (--n <= 0) return;
bn_mul_add_words(&(r[4]),a,n,b[4]);
r+=4;
b+=4;
}
}
#endif