int norm_shift,i,j,loop;
int norm_shift,i,loop;
int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,	   BN_CTX *ctx)	{	int norm_shift,i,j,loop;	BIGNUM *tmp,wnum,*snum,*sdiv,*res;	BN_ULONG *resp,*wnump;	BN_ULONG d0,d1;	int num_n,div_n;	bn_check_top(dv);	bn_check_top(rm);	bn_check_top(num);	bn_check_top(divisor);	if (BN_is_zero(divisor))		{		BNerr(BN_F_BN_DIV,BN_R_DIV_BY_ZERO);		return(0);		}	if (BN_ucmp(num,divisor) < 0)		{		if (rm != NULL)			{ if (BN_copy(rm,num) == NULL) return(0); }		if (dv != NULL) BN_zero(dv);		return(1);		}	BN_CTX_start(ctx);	tmp=BN_CTX_get(ctx);	snum=BN_CTX_get(ctx);	sdiv=BN_CTX_get(ctx);	if (dv == NULL)		res=BN_CTX_get(ctx);	else	res=dv;	if (sdiv == NULL || res == NULL) goto err;	tmp->neg=0;	/* First we normalise the numbers */	norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);	if (!(BN_lshift(sdiv,divisor,norm_shift))) goto err;	sdiv->neg=0;	norm_shift+=BN_BITS2;	if (!(BN_lshift(snum,num,norm_shift))) goto err;	snum->neg=0;	div_n=sdiv->top;	num_n=snum->top;	loop=num_n-div_n;	/* Lets setup a 'window' into snum	 * This is the part that corresponds to the current	 * 'area' being divided */	BN_init(&wnum);	wnum.flags = BN_FLG_STATIC_DATA; /* prevent accidental "expands" */	wnum.d=	 &(snum->d[loop]);	wnum.top= div_n;	wnum.dmax= snum->dmax - loop; /* so we don't step out of bounds */	/* Get the top 2 words of sdiv */	/* div_n=sdiv->top; */	d0=sdiv->d[div_n-1];	d1=(div_n == 1)?0:sdiv->d[div_n-2];	/* pointer to the 'top' of snum */	wnump= &(snum->d[num_n-1]);	/* Setup to 'res' */	res->neg= (num->neg^divisor->neg);	if (!bn_wexpand(res,(loop+1))) goto err;	res->top=loop;	resp= &(res->d[loop-1]);	/* space for temp */	if (!bn_wexpand(tmp,(div_n+1))) goto err;	bn_correct_top(&wnum);	if (BN_ucmp(&wnum,sdiv) >= 0)		{		if (!BN_usub(&wnum,&wnum,sdiv)) goto err;		*resp=1;		res->d[res->top-1]=1;		}	else		res->top--;	if (res->top == 0)		res->neg = 0;	resp--;	for (i=0; i<loop-1; i++)		{		BN_ULONG q,l0;#if defined(BN_DIV3W) && !defined(OPENSSL_NO_ASM)		BN_ULONG bn_div_3_words(BN_ULONG*,BN_ULONG,BN_ULONG);		q=bn_div_3_words(wnump,d1,d0);#else		BN_ULONG n0,n1,rem=0;		n0=wnump[0];		n1=wnump[-1];		if (n0 == d0)			q=BN_MASK2;		else 			/* n0 < d0 */			{#ifdef BN_LLONG			BN_ULLONG t2;#if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)			q=(BN_ULONG)(((((BN_ULLONG)n0)<<BN_BITS2)|n1)/d0);#else			q=bn_div_words(n0,n1,d0);#ifdef BN_DEBUG_LEVITTE			fprintf(stderr,"DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\X) -> 0x%08X\n",				n0, n1, d0, q);#endif#endif#ifndef REMAINDER_IS_ALREADY_CALCULATED			/*			 * rem doesn't have to be BN_ULLONG. The least we			 * know it's less that d0, isn't it?			 */			rem=(n1-q*d0)&BN_MASK2;#endif			t2=(BN_ULLONG)d1*q;			for (;;)				{				if (t2 <= ((((BN_ULLONG)rem)<<BN_BITS2)|wnump[-2]))					break;				q--;				rem += d0;				if (rem < d0) break; /* don't let rem overflow */				t2 -= d1;				}#else /* !BN_LLONG */			BN_ULONG t2l,t2h,ql,qh;			q=bn_div_words(n0,n1,d0);#ifdef BN_DEBUG_LEVITTE			fprintf(stderr,"DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\X) -> 0x%08X\n",				n0, n1, d0, q);#endif#ifndef REMAINDER_IS_ALREADY_CALCULATED			rem=(n1-q*d0)&BN_MASK2;#endif#if defined(BN_UMULT_LOHI)			BN_UMULT_LOHI(t2l,t2h,d1,q);#elif defined(BN_UMULT_HIGH)			t2l = d1 * q;			t2h = BN_UMULT_HIGH(d1,q);#else			t2l=LBITS(d1); t2h=HBITS(d1);			ql =LBITS(q);  qh =HBITS(q);			mul64(t2l,t2h,ql,qh); /* t2=(BN_ULLONG)d1*q; */#endif			for (;;)				{				if ((t2h < rem) ||					((t2h == rem) && (t2l <= wnump[-2])))					break;				q--;				rem += d0;				if (rem < d0) break; /* don't let rem overflow */				if (t2l < d1) t2h--; t2l -= d1;				}#endif /* !BN_LLONG */			}#endif /* !BN_DIV3W */		l0=bn_mul_words(tmp->d,sdiv->d,div_n,q);		wnum.d--; wnum.top++; wnum.dmax++;		tmp->d[div_n]=l0;		/* XXX: Couldn't we replace this with;		 *    tmp->top = div_n;		 *    bn_fix_top(tmp);		 */		for (j=div_n+1; j>0; j--)			if (tmp->d[j-1]) break;		tmp->top=j;		j=wnum.top;		bn_correct_top(&wnum);		if (!BN_sub(&wnum,&wnum,tmp)) goto err;		snum->top=snum->top+wnum.top-j;		if (wnum.neg)			{			q--;			j=wnum.top;			if (!BN_add(&wnum,&wnum,sdiv)) goto err;			snum->top+=wnum.top-j;			}		*(resp--)=q;		wnump--;		}	if (rm != NULL)		{		/* Keep a copy of the neg flag in num because if rm==num		 * BN_rshift() will overwrite it.		 */		int neg = num->neg;		bn_correct_top(snum);		BN_rshift(rm,snum,norm_shift);		if (!BN_is_zero(rm))			rm->neg = neg;		bn_check_top(rm);		}	BN_CTX_end(ctx);	return(1);err:	bn_check_top(rm);	BN_CTX_end(ctx);	return(0);	}