else res->top--; resp--;  for (i=0; i<loop-1; i++) { BN_ULONG q,l0; #ifdef BN_DIV3W q=bn_div_3_words(wnump,d1,d0); #else  #if !defined(NO_ASM) && !defined(PEDANTIC) # if defined(__GNUC__) && __GNUC__>=2 #  if defined(__i386)  #  define bn_div_words(n0,n1,d0)		\ ({  asm volatile (			\ "divl	%4"			\ : "=a"(q), "=d"(rem)		\ : "a"(n1), "d"(n0), "g"(d0)	\ : "cc");			\ q;					\ }) #  define REMAINDER_IS_ALREADY_CALCULATED #  endif  # endif  #endif  BN_ULONG n0,n1,rem=0;  n0=wnump[0]; n1=wnump[-1]; if (n0 == d0) { q=BN_MASK2; #ifdef REMAINDER_IS_ALREADY_CALCULATED  rem=(n1-q*d0)&BN_MASK2; #endif } else  #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); #endif { #ifdef BN_LLONG BN_ULLONG t2;  #ifndef REMAINDER_IS_ALREADY_CALCULATED  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;  t2 -= d1; } #else BN_ULONG t2l,t2h,ql,qh;  #ifndef REMAINDER_IS_ALREADY_CALCULATED  rem=(n1-q*d0)&BN_MASK2; #endif #ifdef 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);  #endif  for (;;) { if ((t2h < rem) || ((t2h == rem) && (t2l <= wnump[-2]))) break; q--; rem += d0; if (rem < d0) break;  if (t2l < d1) t2h--; t2l -= d1; } #endif } #endif  l0=bn_mul_words(tmp->d,sdiv->d,div_n,q); wnum.d--; wnum.top++; tmp->d[div_n]=l0; for (j=div_n+1; j>0; j--) if (tmp->d[j-1]) break; tmp->top=j;  j=wnum.top; BN_sub(&wnum,&wnum,tmp);  snum->top=snum->top+wnum.top-j;  if (wnum.neg) { q--; j=wnum.top; BN_add(&wnum,&wnum,sdiv); snum->top+=wnum.top-j; } *(resp--)=q; wnump--; } if (rm != NULL) { BN_rshift(rm,snum,norm_shift); rm->neg=num->neg; } return(1); err: return(0);
rem->neg=BN_is_zero(rem)?0:m->neg; dv->neg=m->neg^d->neg; ret = 1; end: BN_CTX_end(ctx); return(ret);
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(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);		}	tmp= &(ctx->bn[ctx->tos]);	tmp->neg=0;	snum= &(ctx->bn[ctx->tos+1]);	sdiv= &(ctx->bn[ctx->tos+2]);	if (dv == NULL)		res= &(ctx->bn[ctx->tos+3]);	else	res=dv;	/* First we normalise the numbers */	norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);	BN_lshift(sdiv,divisor,norm_shift);	sdiv->neg=0;	norm_shift+=BN_BITS2;	BN_lshift(snum,num,norm_shift);	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.d=	 &(snum->d[loop]);	wnum.top= div_n;	wnum.max= snum->max+1; /* a bit of a lie */	/* Get the top 2 words of sdiv */	/* i=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;	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--;	resp--;	for (i=0; i<loop-1; i++)		{		BN_ULONG q,l0;#ifdef BN_DIV3W		q=bn_div_3_words(wnump,d1,d0);#else#if !defined(NO_ASM) && !defined(PEDANTIC)# if defined(__GNUC__) && __GNUC__>=2#  if defined(__i386)   /*    * There were two reasons for implementing this template:    * - GNU C generates a call to a function (__udivdi3 to be exact)    *   in reply to ((((BN_ULLONG)n0)<<BN_BITS2)|n1)/d0 (I fail to    *   understand why...);    * - divl doesn't only calculate quotient, but also leaves    *   remainder in %edx which we can definitely use here:-)    *    *					<appro@fy.chalmers.se>    */#  define bn_div_words(n0,n1,d0)		\	({  asm volatile (			\		"divl	%4"			\		: "=a"(q), "=d"(rem)		\		: "a"(n1), "d"(n0), "g"(d0)	\		: "cc");			\	    q;					\	})#  define REMAINDER_IS_ALREADY_CALCULATED#  endif /* __<cpu> */# endif /* __GNUC__ */#endif /* NO_ASM */		BN_ULONG n0,n1,rem=0;		n0=wnump[0];		n1=wnump[-1];		if (n0 == d0)			{			q=BN_MASK2;#ifdef REMAINDER_IS_ALREADY_CALCULATED /* in this case it isn't */			rem=(n1-q*d0)&BN_MASK2;#endif			}		else /* n0 < d0 */#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);#endif		{#ifdef BN_LLONG		BN_ULLONG t2;#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_ULONG t2l,t2h,ql,qh;#ifndef REMAINDER_IS_ALREADY_CALCULATED		/*		 * It's more than enough with the only multiplication.		 * See the comment above in BN_LLONG section...		 */		rem=(n1-q*d0)&BN_MASK2;#endif#ifdef 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		}#endif /* !BN_DIV3W */		l0=bn_mul_words(tmp->d,sdiv->d,div_n,q);		wnum.d--; wnum.top++;		tmp->d[div_n]=l0;		for (j=div_n+1; j>0; j--)			if (tmp->d[j-1]) break;		tmp->top=j;		j=wnum.top;		BN_sub(&wnum,&wnum,tmp);		snum->top=snum->top+wnum.top-j;		if (wnum.neg)			{			q--;			j=wnum.top;			BN_add(&wnum,&wnum,sdiv);			snum->top+=wnum.top-j;			}		*(resp--)=q;		wnump--;		}	if (rm != NULL)		{		BN_rshift(rm,snum,norm_shift);		rm->neg=num->neg;		}	return(1);err:	return(0);	}