bn_asm.c

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/* crypto/bn/bn_asm.c */
/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([email protected]).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([email protected])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([email protected])"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

/* Removed NDEBUG redefinition - pcg */

#include <stdio.h>
#include <assert.h>
#if defined( _WIN32_WCE ) && _WIN32_WCE < 400
  #define assert( x )
#else
  #include <assert.h>
#endif /* Systems without assert() */
#if defined( INC_ALL )
  #include "bn_lcl.h"
#else
  #include "bn/bn_lcl.h"
#endif /* Compiler-specific includes */

#ifndef BN_ASM 

#if defined(BN_LLONG) || defined(BN_UMULT_HIGH)

BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
    {
    BN_ULONG c1=0;

    assert(num >= 0);
    if (num <= 0) return(c1);

    while (num&~3)
        {
        mul_add(rp[0],ap[0],w,c1);
        mul_add(rp[1],ap[1],w,c1);
        mul_add(rp[2],ap[2],w,c1);
        mul_add(rp[3],ap[3],w,c1);
        ap+=4; rp+=4; num-=4;
        }
    if (num)
        {
        mul_add(rp[0],ap[0],w,c1); if (--num==0) return c1;
        mul_add(rp[1],ap[1],w,c1); if (--num==0) return c1;
        mul_add(rp[2],ap[2],w,c1); return c1;
        }

    return(c1);
    }

BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
    {
    BN_ULONG c1=0;

    assert(num >= 0);
    if (num <= 0) return(c1);

    while (num&~3)
        {
        mul(rp[0],ap[0],w,c1);
        mul(rp[1],ap[1],w,c1);
        mul(rp[2],ap[2],w,c1);
        mul(rp[3],ap[3],w,c1);
        ap+=4; rp+=4; num-=4;
        }
    if (num)
        {
        mul(rp[0],ap[0],w,c1); if (--num == 0) return c1;
        mul(rp[1],ap[1],w,c1); if (--num == 0) return c1;
        mul(rp[2],ap[2],w,c1);
        }
    return(c1);
    }

void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
        {
    assert(n >= 0);
    if (n <= 0) return;
    while (n&~3)
        {
        sqr(r[0],r[1],a[0]);
        sqr(r[2],r[3],a[1]);
        sqr(r[4],r[5],a[2]);
        sqr(r[6],r[7],a[3]);
        a+=4; r+=8; n-=4;
        }
    if (n)
        {
        sqr(r[0],r[1],a[0]); if (--n == 0) return;
        sqr(r[2],r[3],a[1]); if (--n == 0) return;
        sqr(r[4],r[5],a[2]);
        }
    }

#else /* !(defined(BN_LLONG) || defined(BN_UMULT_HIGH)) */

BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
    {
    BN_ULONG c=0;
    BN_ULONG bl,bh;

    assert(num >= 0);
    if (num <= 0) return((BN_ULONG)0);

    bl=LBITS(w);
    bh=HBITS(w);

    for (;;)
        {
        mul_add(rp[0],ap[0],bl,bh,c);
        if (--num == 0) break;
        mul_add(rp[1],ap[1],bl,bh,c);
        if (--num == 0) break;
        mul_add(rp[2],ap[2],bl,bh,c);
        if (--num == 0) break;
        mul_add(rp[3],ap[3],bl,bh,c);
        if (--num == 0) break;
        ap+=4;
        rp+=4;
        }
    return(c);
    }

BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
    {
    BN_ULONG carry=0;
    BN_ULONG bl,bh;

    assert(num >= 0);
    if (num <= 0) return((BN_ULONG)0);

    bl=LBITS(w);
    bh=HBITS(w);

    for (;;)
        {
        mul(rp[0],ap[0],bl,bh,carry);
        if (--num == 0) break;
        mul(rp[1],ap[1],bl,bh,carry);
        if (--num == 0) break;
        mul(rp[2],ap[2],bl,bh,carry);
        if (--num == 0) break;
        mul(rp[3],ap[3],bl,bh,carry);
        if (--num == 0) break;
        ap+=4;
        rp+=4;
        }
    return(carry);
    }

void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
        {
    assert(n >= 0);
    if (n <= 0) return;
    for (;;)
        {
        sqr64(r[0],r[1],a[0]);
        if (--n == 0) break;

        sqr64(r[2],r[3],a[1]);
        if (--n == 0) break;

        sqr64(r[4],r[5],a[2]);
        if (--n == 0) break;

        sqr64(r[6],r[7],a[3]);
        if (--n == 0) break;

        a+=4;
        r+=8;
        }
    }

#endif /* !(defined(BN_LLONG) || defined(BN_UMULT_HIGH)) */

#if defined(BN_LLONG) && defined(BN_DIV2W)

BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
    {
    return((BN_ULONG)(((((BN_ULLONG)h)<<BN_BITS2)|l)/(BN_ULLONG)d));
    }

#else

/* Divide h,l by d and return the result. */
/* I need to test this some more :-( */
BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
    {
    BN_ULONG dh,dl,q,ret=0,th,tl,t;
    int i,count=2;

    if (d == 0) return(BN_MASK2);

    i=BN_num_bits_word(d);
    assert((i == BN_BITS2) || (h <= (BN_ULONG)1<<i));

    i=BN_BITS2-i;
    if (h >= d) h-=d;

    if (i)
        {
        d<<=i;
        h=(h<<i)|(l>>(BN_BITS2-i));
        l<<=i;
        }
    dh=(d&BN_MASK2h)>>BN_BITS4;
    dl=(d&BN_MASK2l);
    for (;;)
        {
        if ((h>>BN_BITS4) == dh)
            q=BN_MASK2l;
        else
            q=h/dh;

        th=q*dh;
        tl=dl*q;
        for (;;)
            {
            t=h-th;
            if ((t&BN_MASK2h) ||
                ((tl) <= (
                    (t<<BN_BITS4)|
                    ((l&BN_MASK2h)>>BN_BITS4))))
                break;
            q--;
            th-=dh;
            tl-=dl;
            }
        t=(tl>>BN_BITS4);
        tl=(tl<<BN_BITS4)&BN_MASK2h;
        th+=t;

        if (l < tl) th++;
        l-=tl;
        if (h < th)
            {
            h+=d;
            q--;
            }
        h-=th;

        if (--count == 0) break;

        ret=q<<BN_BITS4;
        h=((h<<BN_BITS4)|(l>>BN_BITS4))&BN_MASK2;
        l=(l&BN_MASK2l)<<BN_BITS4;
        }
    ret|=q;
    return(ret);
    }
#endif /* !defined(BN_LLONG) && defined(BN_DIV2W) */

#ifdef BN_LLONG
BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
        {
    BN_ULLONG ll=0;

    assert(n >= 0);
    if (n <= 0) return((BN_ULONG)0);

    for (;;)
        {
        ll+=(BN_ULLONG)a[0]+b[0];
        r[0]=(BN_ULONG)ll&BN_MASK2;
        ll>>=BN_BITS2;
        if (--n <= 0) break;

        ll+=(BN_ULLONG)a[1]+b[1];
        r[1]=(BN_ULONG)ll&BN_MASK2;
        ll>>=BN_BITS2;
        if (--n <= 0) break;

        ll+=(BN_ULLONG)a[2]+b[2];
        r[2]=(BN_ULONG)ll&BN_MASK2;
        ll>>=BN_BITS2;
        if (--n <= 0) break;

        ll+=(BN_ULLONG)a[3]+b[3];
        r[3]=(BN_ULONG)ll&BN_MASK2;
        ll>>=BN_BITS2;
        if (--n <= 0) break;

        a+=4;
        b+=4;
        r+=4;
        }
    return((BN_ULONG)ll);
    }
#else /* !BN_LLONG */
BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
        {
    BN_ULONG c,l,t;

    assert(n >= 0);
    if (n <= 0) return((BN_ULONG)0);

    c=0;
    for (;;)
        {
        t=a[0];
        t=(t+c)&BN_MASK2;
        c=(t < c);
        l=(t+b[0])&BN_MASK2;
        c+=(l < t);
        r[0]=l;
        if (--n <= 0) break;

        t=a[1];
        t=(t+c)&BN_MASK2;
        c=(t < c);
        l=(t+b[1])&BN_MASK2;
        c+=(l < t);
        r[1]=l;
        if (--n <= 0) break;

        t=a[2];
        t=(t+c)&BN_MASK2;
        c=(t < c);
        l=(t+b[2])&BN_MASK2;
        c+=(l < t);
        r[2]=l;
        if (--n <= 0) break;

        t=a[3];
        t=(t+c)&BN_MASK2;
        c=(t < c);
        l=(t+b[3])&BN_MASK2;
        c+=(l < t);
        r[3]=l;
        if (--n <= 0) break;

        a+=4;
        b+=4;
        r+=4;
        }
    return((BN_ULONG)c);
    }
#endif /* !BN_LLONG */

BN_ULONG bn_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
        {
    BN_ULONG t1,t2;
    int c=0;

    assert(n >= 0);
    if (n <= 0) return((BN_ULONG)0);

    for (;;)
        {
        t1=a[0]; t2=b[0];
        r[0]=(t1-t2-c)&BN_MASK2;
        if (t1 != t2) c=(t1 < t2);
        if (--n <= 0) break;

        t1=a[1]; t2=b[1];
        r[1]=(t1-t2-c)&BN_MASK2;
        if (t1 != t2) c=(t1 < t2);
        if (--n <= 0) break;

        t1=a[2]; t2=b[2];
        r[2]=(t1-t2-c)&BN_MASK2;
        if (t1 != t2) c=(t1 < t2);
        if (--n <= 0) break;

        t1=a[3]; t2=b[3];
        r[3]=(t1-t2-c)&BN_MASK2;
        if (t1 != t2) c=(t1 < t2);
        if (--n <= 0) break;

        a+=4;
        b+=4;
        r+=4;
        }
    return(c);
    }

#ifdef BN_MUL_COMBA

#undef bn_mul_comba8
#undef bn_mul_comba4
#undef bn_sqr_comba8
#undef bn_sqr_comba4

/* mul_add_c(a,b,c0,c1,c2)  -- c+=a*b for three word number c=(c2,c1,c0) */
/* mul_add_c2(a,b,c0,c1,c2) -- c+=2*a*b for three word number c=(c2,c1,c0) */
/* sqr_add_c(a,i,c0,c1,c2)  -- c+=a[i]^2 for three word number c=(c2,c1,c0) */
/* sqr_add_c2(a,i,c0,c1,c2) -- c+=2*a[i]*a[j] for three word number c=(c2,c1,c0) */

#ifdef BN_LLONG
#define mul_add_c(a,b,c0,c1,c2) \
    t=(BN_ULLONG)a*b; \
    t1=(BN_ULONG)Lw(t); \
    t2=(BN_ULONG)Hw(t); \
    c0=(c0+t1)&BN_MASK2; if ((c0) < t1) t2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define mul_add_c2(a,b,c0,c1,c2) \
    t=(BN_ULLONG)a*b; \
    tt=(t+t)&BN_MASK; \
    if (tt < t) c2++; \
    t1=(BN_ULONG)Lw(tt); \
    t2=(BN_ULONG)Hw(tt); \
    c0=(c0+t1)&BN_MASK2;  \
    if ((c0 < t1) && (((++t2)&BN_MASK2) == 0)) c2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define sqr_add_c(a,i,c0,c1,c2) \
    t=(BN_ULLONG)a[i]*a[i]; \
    t1=(BN_ULONG)Lw(t); \
    t2=(BN_ULONG)Hw(t); \
    c0=(c0+t1)&BN_MASK2; if ((c0) < t1) t2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define sqr_add_c2(a,i,j,c0,c1,c2) \
    mul_add_c2((a)[i],(a)[j],c0,c1,c2)

#elif defined(BN_UMULT_HIGH)

#define mul_add_c(a,b,c0,c1,c2) {   \
    BN_ULONG ta=(a),tb=(b);     \
    t1 = ta * tb;           \
    t2 = BN_UMULT_HIGH(ta,tb);  \
    c0 += t1; t2 += (c0<t1)?1:0;    \
    c1 += t2; c2 += (c1<t2)?1:0;    \
    }

#define mul_add_c2(a,b,c0,c1,c2) {  \
    BN_ULONG ta=(a),tb=(b),t0;  \
    t1 = BN_UMULT_HIGH(ta,tb);  \
    t0 = ta * tb;           \
    t2 = t1+t1; c2 += (t2<t1)?1:0;  \
    t1 = t0+t0; t2 += (t1<t0)?1:0;  \
    c0 += t1; t2 += (c0<t1)?1:0;    \
    c1 += t2; c2 += (c1<t2)?1:0;    \
    }

#define sqr_add_c(a,i,c0,c1,c2) {   \
    BN_ULONG ta=(a)[i];     \
    t1 = ta * ta;           \
    t2 = BN_UMULT_HIGH(ta,ta);  \
    c0 += t1; t2 += (c0<t1)?1:0;    \
    c1 += t2; c2 += (c1<t2)?1:0;    \
    }

#define sqr_add_c2(a,i,j,c0,c1,c2)  \
    mul_add_c2((a)[i],(a)[j],c0,c1,c2)

#else /* !BN_LLONG */
#define mul_add_c(a,b,c0,c1,c2) \
    t1=LBITS(a); t2=HBITS(a); \
    bl=LBITS(b); bh=HBITS(b); \
    mul64(t1,t2,bl,bh); \
    c0=(c0+t1)&BN_MASK2; if ((c0) < t1) t2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define mul_add_c2(a,b,c0,c1,c2) \
    t1=LBITS(a); t2=HBITS(a); \
    bl=LBITS(b); bh=HBITS(b); \
    mul64(t1,t2,bl,bh); \
    if (t2 & BN_TBIT) c2++; \
    t2=(t2+t2)&BN_MASK2; \
    if (t1 & BN_TBIT) t2++; \
    t1=(t1+t1)&BN_MASK2; \
    c0=(c0+t1)&BN_MASK2;  \
    if ((c0 < t1) && (((++t2)&BN_MASK2) == 0)) c2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define sqr_add_c(a,i,c0,c1,c2) \
    sqr64(t1,t2,(a)[i]); \
    c0=(c0+t1)&BN_MASK2; if ((c0) < t1) t2++; \
    c1=(c1+t2)&BN_MASK2; if ((c1) < t2) c2++;

#define sqr_add_c2(a,i,j,c0,c1,c2) \
    mul_add_c2((a)[i],(a)[j],c0,c1,c2)
#endif /* !BN_LLONG */

void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
    {
#if defined( BN_LLONG ) /* pcg */
    BN_ULLONG t;
#elif !defined( BN_UMULT_HIGH )
    BN_ULONG bl,bh;
#endif
    BN_ULONG t1,t2;
    BN_ULONG c1,c2,c3;

    c1=0;
    c2=0;
    c3=0;
    mul_add_c(a[0],b[0],c1,c2,c3);
    r[0]=c1;
    c1=0;
    mul_add_c(a[0],b[1],c2,c3,c1);
    mul_add_c(a[1],b[0],c2,c3,c1);
    r[1]=c2;
    c2=0;
    mul_add_c(a[2],b[0],c3,c1,c2);
    mul_add_c(a[1],b[1],c3,c1,c2);
    mul_add_c(a[0],b[2],c3,c1,c2);
    r[2]=c3;
    c3=0;
    mul_add_c(a[0],b[3],c1,c2,c3);
    mul_add_c(a[1],b[2],c1,c2,c3);
    mul_add_c(a[2],b[1],c1,c2,c3);
    mul_add_c(a[3],b[0],c1,c2,c3);
    r[3]=c1;
    c1=0;
    mul_add_c(a[4],b[0],c2,c3,c1);
    mul_add_c(a[3],b[1],c2,c3,c1);
    mul_add_c(a[2],b[2],c2,c3,c1);
    mul_add_c(a[1],b[3],c2,c3,c1);
    mul_add_c(a[0],b[4],c2,c3,c1);
    r[4]=c2;
    c2=0;
    mul_add_c(a[0],b[5],c3,c1,c2);
    mul_add_c(a[1],b[4],c3,c1,c2);
    mul_add_c(a[2],b[3],c3,c1,c2);
    mul_add_c(a[3],b[2],c3,c1,c2);
    mul_add_c(a[4],b[1],c3,c1,c2);
    mul_add_c(a[5],b[0],c3,c1,c2);
    r[5]=c3;
    c3=0;
    mul_add_c(a[6],b[0],c1,c2,c3);
    mul_add_c(a[5],b[1],c1,c2,c3);
    mul_add_c(a[4],b[2],c1,c2,c3);
    mul_add_c(a[3],b[3],c1,c2,c3);
    mul_add_c(a[2],b[4],c1,c2,c3);
    mul_add_c(a[1],b[5],c1,c2,c3);
    mul_add_c(a[0],b[6],c1,c2,c3);
    r[6]=c1;
    c1=0;
    mul_add_c(a[0],b[7],c2,c3,c1);
    mul_add_c(a[1],b[6],c2,c3,c1);
    mul_add_c(a[2],b[5],c2,c3,c1);
    mul_add_c(a[3],b[4],c2,c3,c1);
    mul_add_c(a[4],b[3],c2,c3,c1);
    mul_add_c(a[5],b[2],c2,c3,c1);
    mul_add_c(a[6],b[1],c2,c3,c1);
    mul_add_c(a[7],b[0],c2,c3,c1);
    r[7]=c2;
    c2=0;
    mul_add_c(a[7],b[1],c3,c1,c2);
    mul_add_c(a[6],b[2],c3,c1,c2);
    mul_add_c(a[5],b[3],c3,c1,c2);
    mul_add_c(a[4],b[4],c3,c1,c2);
    mul_add_c(a[3],b[5],c3,c1,c2);
    mul_add_c(a[2],b[6],c3,c1,c2);
    mul_add_c(a[1],b[7],c3,c1,c2);
    r[8]=c3;
    c3=0;
    mul_add_c(a[2],b[7],c1,c2,c3);
    mul_add_c(a[3],b[6],c1,c2,c3);
    mul_add_c(a[4],b[5],c1,c2,c3);
    mul_add_c(a[5],b[4],c1,c2,c3);
    mul_add_c(a[6],b[3],c1,c2,c3);
    mul_add_c(a[7],b[2],c1,c2,c3);
    r[9]=c1;
    c1=0;
    mul_add_c(a[7],b[3],c2,c3,c1);
    mul_add_c(a[6],b[4],c2,c3,c1);
    mul_add_c(a[5],b[5],c2,c3,c1);
    mul_add_c(a[4],b[6],c2,c3,c1);
    mul_add_c(a[3],b[7],c2,c3,c1);
    r[10]=c2;
    c2=0;
    mul_add_c(a[4],b[7],c3,c1,c2);
    mul_add_c(a[5],b[6],c3,c1,c2);
    mul_add_c(a[6],b[5],c3,c1,c2);
    mul_add_c(a[7],b[4],c3,c1,c2);
    r[11]=c3;
    c3=0;
    mul_add_c(a[7],b[5],c1,c2,c3);
    mul_add_c(a[6],b[6],c1,c2,c3);
    mul_add_c(a[5],b[7],c1,c2,c3);
    r[12]=c1;
    c1=0;
    mul_add_c(a[6],b[7],c2,c3,c1);
    mul_add_c(a[7],b[6],c2,c3,c1);
    r[13]=c2;
    c2=0;
    mul_add_c(a[7],b[7],c3,c1,c2);
    r[14]=c3;
    r[15]=c1;
    }

void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
    {
#if defined( BN_LLONG ) /* pcg */
    BN_ULLONG t;
#elif !defined( BN_UMULT_HIGH )
    BN_ULONG bl,bh;
#endif
    BN_ULONG t1,t2;
    BN_ULONG c1,c2,c3;

    c1=0;
    c2=0;
    c3=0;
    mul_add_c(a[0],b[0],c1,c2,c3);
    r[0]=c1;
    c1=0;
    mul_add_c(a[0],b[1],c2,c3,c1);
    mul_add_c(a[1],b[0],c2,c3,c1);
    r[1]=c2;
    c2=0;
    mul_add_c(a[2],b[0],c3,c1,c2);
    mul_add_c(a[1],b[1],c3,c1,c2);
    mul_add_c(a[0],b[2],c3,c1,c2);
    r[2]=c3;
    c3=0;
    mul_add_c(a[0],b[3],c1,c2,c3);
    mul_add_c(a[1],b[2],c1,c2,c3);
    mul_add_c(a[2],b[1],c1,c2,c3);
    mul_add_c(a[3],b[0],c1,c2,c3);
    r[3]=c1;
    c1=0;
    mul_add_c(a[3],b[1],c2,c3,c1);
    mul_add_c(a[2],b[2],c2,c3,c1);
    mul_add_c(a[1],b[3],c2,c3,c1);
    r[4]=c2;
    c2=0;
    mul_add_c(a[2],b[3],c3,c1,c2);
    mul_add_c(a[3],b[2],c3,c1,c2);
    r[5]=c3;
    c3=0;
    mul_add_c(a[3],b[3],c1,c2,c3);
    r[6]=c1;
    r[7]=c2;
    }

void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
    {
#if defined( BN_LLONG ) /* pcg */
    BN_ULLONG t, tt;
#elif !defined( BN_UMULT_HIGH )
    BN_ULONG bl,bh;
#endif
    BN_ULONG t1,t2;
    BN_ULONG c1,c2,c3;

    c1=0;
    c2=0;
    c3=0;
    sqr_add_c(a,0,c1,c2,c3);
    r[0]=c1;
    c1=0;
    sqr_add_c2(a,1,0,c2,c3,c1);
    r[1]=c2;
    c2=0;
    sqr_add_c(a,1,c3,c1,c2);
    sqr_add_c2(a,2,0,c3,c1,c2);
    r[2]=c3;
    c3=0;
    sqr_add_c2(a,3,0,c1,c2,c3);
    sqr_add_c2(a,2,1,c1,c2,c3);
    r[3]=c1;
    c1=0;
    sqr_add_c(a,2,c2,c3,c1);
    sqr_add_c2(a,3,1,c2,c3,c1);
    sqr_add_c2(a,4,0,c2,c3,c1);
    r[4]=c2;
    c2=0;
    sqr_add_c2(a,5,0,c3,c1,c2);
    sqr_add_c2(a,4,1,c3,c1,c2);
    sqr_add_c2(a,3,2,c3,c1,c2);
    r[5]=c3;
    c3=0;
    sqr_add_c(a,3,c1,c2,c3);
    sqr_add_c2(a,4,2,c1,c2,c3);
    sqr_add_c2(a,5,1,c1,c2,c3);
    sqr_add_c2(a,6,0,c1,c2,c3);
    r[6]=c1;
    c1=0;
    sqr_add_c2(a,7,0,c2,c3,c1);
    sqr_add_c2(a,6,1,c2,c3,c1);
    sqr_add_c2(a,5,2,c2,c3,c1);
    sqr_add_c2(a,4,3,c2,c3,c1);
    r[7]=c2;
    c2=0;
    sqr_add_c(a,4,c3,c1,c2);
    sqr_add_c2(a,5,3,c3,c1,c2);
    sqr_add_c2(a,6,2,c3,c1,c2);
    sqr_add_c2(a,7,1,c3,c1,c2);
    r[8]=c3;
    c3=0;
    sqr_add_c2(a,7,2,c1,c2,c3);
    sqr_add_c2(a,6,3,c1,c2,c3);
    sqr_add_c2(a,5,4,c1,c2,c3);
    r[9]=c1;
    c1=0;
    sqr_add_c(a,5,c2,c3,c1);
    sqr_add_c2(a,6,4,c2,c3,c1);
    sqr_add_c2(a,7,3,c2,c3,c1);
    r[10]=c2;
    c2=0;
    sqr_add_c2(a,7,4,c3,c1,c2);
    sqr_add_c2(a,6,5,c3,c1,c2);
    r[11]=c3;
    c3=0;
    sqr_add_c(a,6,c1,c2,c3);
    sqr_add_c2(a,7,5,c1,c2,c3);
    r[12]=c1;
    c1=0;
    sqr_add_c2(a,7,6,c2,c3,c1);
    r[13]=c2;
    c2=0;
    sqr_add_c(a,7,c3,c1,c2);
    r[14]=c3;
    r[15]=c1;
    }

void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
    {
#if defined( BN_LLONG ) /* pcg */
    BN_ULLONG t, tt;
#elif !defined( BN_UMULT_HIGH )
    BN_ULONG bl,bh;
#endif
    BN_ULONG t1,t2;
    BN_ULONG c1,c2,c3;

    c1=0;
    c2=0;
    c3=0;
    sqr_add_c(a,0,c1,c2,c3);
    r[0]=c1;
    c1=0;
    sqr_add_c2(a,1,0,c2,c3,c1);
    r[1]=c2;
    c2=0;
    sqr_add_c(a,1,c3,c1,c2);
    sqr_add_c2(a,2,0,c3,c1,c2);
    r[2]=c3;
    c3=0;
    sqr_add_c2(a,3,0,c1,c2,c3);
    sqr_add_c2(a,2,1,c1,c2,c3);
    r[3]=c1;
    c1=0;
    sqr_add_c(a,2,c2,c3,c1);
    sqr_add_c2(a,3,1,c2,c3,c1);
    r[4]=c2;
    c2=0;
    sqr_add_c2(a,3,2,c3,c1,c2);
    r[5]=c3;
    c3=0;
    sqr_add_c(a,3,c1,c2,c3);
    r[6]=c1;
    r[7]=c2;
    }
#else /* !BN_MUL_COMBA */

/* hmm... is it faster just to do a multiply? */
#undef bn_sqr_comba4
void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
    {
    BN_ULONG t[8];
    bn_sqr_normal(r,a,4,t);
    }

#undef bn_sqr_comba8
void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
    {
    BN_ULONG t[16];
    bn_sqr_normal(r,a,8,t);
    }

void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
    {
    r[4]=bn_mul_words(    &(r[0]),a,4,b[0]);
    r[5]=bn_mul_add_words(&(r[1]),a,4,b[1]);
    r[6]=bn_mul_add_words(&(r[2]),a,4,b[2]);
    r[7]=bn_mul_add_words(&(r[3]),a,4,b[3]);
    }

void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
    {
    r[ 8]=bn_mul_words(    &(r[0]),a,8,b[0]);
    r[ 9]=bn_mul_add_words(&(r[1]),a,8,b[1]);
    r[10]=bn_mul_add_words(&(r[2]),a,8,b[2]);
    r[11]=bn_mul_add_words(&(r[3]),a,8,b[3]);
    r[12]=bn_mul_add_words(&(r[4]),a,8,b[4]);
    r[13]=bn_mul_add_words(&(r[5]),a,8,b[5]);
    r[14]=bn_mul_add_words(&(r[6]),a,8,b[6]);
    r[15]=bn_mul_add_words(&(r[7]),a,8,b[7]);
    }

#endif /* !BN_MUL_COMBA */

#endif /* !BN_ASM */