bn_asm.c

#include "bn.h"

#ifndef WITH_LIBCRYPTO
//FIXME Not checked on threadsafety yet; after checking please remove this line
/* crypto/bn/bn_asm.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * 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 (tjh@cryptsoft.com).
 *
 * 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 (eay@cryptsoft.com)"
 *    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 (tjh@cryptsoft.com)"
 *
 * 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 license 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 license
 * [including the GNU Public License.]
 */

#ifndef BN_DEBUG
# undef NDEBUG /* avoid conflicting definitions */
# define NDEBUG
#endif

#include <stdio.h>
#include <assert.h>
#include "bn_lcl.h"
#include "openssl_mods.h"

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

BN_ULONG bn_mul_add_words(BN_ULONG *rp, 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, 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, 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, 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, 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, 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, BN_ULONG *a, 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, BN_ULONG *a, 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, BN_ULONG *a, 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)
{
#ifdef BN_LLONG
	BN_ULLONG t;
#else
	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)
{
#ifdef BN_LLONG
	BN_ULLONG t;
#else
	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, BN_ULONG *a)
{
#ifdef BN_LLONG
	BN_ULLONG t, tt;
#else
	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, BN_ULONG *a)
{
#ifdef BN_LLONG
	BN_ULLONG t, tt;
#else
	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