/* 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 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.]

 */

#ifndef BN_DEBUG

# undef NDEBUG /* avoid conflicting definitions */

# define NDEBUG

#endif

#include <stdio.h>

#include <assert.h>

#include "cryptlib.h"

#include "bn_lcl.h"

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

EXPORT_C 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);

	} 

EXPORT_C 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);

	} 

EXPORT_C 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)) */

EXPORT_C 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);

	} 

EXPORT_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);

	} 

EXPORT_C 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)

EXPORT_C 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 :-( */

EXPORT_C 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

EXPORT_C 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 */

EXPORT_C 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 */

EXPORT_C 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_LOHI)

#define mul_add_c(a,b,c0,c1,c2)	{	\

	BN_ULONG ta=(a),tb=(b);		\

	BN_UMULT_LOHI(t1,t2,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;	\

	BN_UMULT_LOHI(t0,t1,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];		\

	BN_UMULT_LOHI(t1,t2,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)

#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++;