/* * linux/kernel/math/div.c * * (C) 1991 Linus Torvalds *//* * temporary real division routine. */#include <linux/math_emu.h>static void shift_left(int * c){	__asm__ __volatile__("movl (%0),%%eax ; addl %%eax,(%0)\n\t"		"movl 4(%0),%%eax ; adcl %%eax,4(%0)\n\t"		"movl 8(%0),%%eax ; adcl %%eax,8(%0)\n\t"		"movl 12(%0),%%eax ; adcl %%eax,12(%0)"		::"r" ((long) c):"ax");}static void shift_right(int * c){	__asm__("shrl $1,12(%0) ; rcrl $1,8(%0) ; rcrl $1,4(%0) ; rcrl $1,(%0)"		::"r" ((long) c));}static int try_sub(int * a, int * b){	char ok;	__asm__ __volatile__("movl (%1),%%eax ; subl %%eax,(%2)\n\t"		"movl 4(%1),%%eax ; sbbl %%eax,4(%2)\n\t"		"movl 8(%1),%%eax ; sbbl %%eax,8(%2)\n\t"		"movl 12(%1),%%eax ; sbbl %%eax,12(%2)\n\t"		"setae %%al":"=a" (ok):"c" ((long) a),"d" ((long) b));	return ok;}static void div64(int * a, int * b, int * c){	int tmp[4];	int i;	unsigned int mask = 0;	c += 4;	for (i = 0 ; i<64 ; i++) {		if (!(mask >>= 1)) {			c--;			mask = 0x80000000;		}		tmp[0] = a[0]; tmp[1] = a[1];		tmp[2] = a[2]; tmp[3] = a[3];		if (try_sub(b,tmp)) {			*c |= mask;			a[0] = tmp[0]; a[1] = tmp[1];			a[2] = tmp[2]; a[3] = tmp[3];		}		shift_right(b);	}}void fdiv(const temp_real * src1, const temp_real * src2, temp_real * result){	int i,sign;	int a[4],b[4],tmp[4] = {0,0,0,0};	sign = (src1->exponent ^ src2->exponent) & 0x8000;	if (!(src2->a || src2->b)) {		set_ZE();		return;	}	i = (src1->exponent & 0x7fff) - (src2->exponent & 0x7fff) + 16383;	if (i<0) {		set_UE();		result->exponent = sign;		result->a = result->b = 0;		return;	}	a[0] = a[1] = 0;	a[2] = src1->a;	a[3] = src1->b;	b[0] = b[1] = 0;	b[2] = src2->a;	b[3] = src2->b;	while (b[3] >= 0) {		i++;		shift_left(b);	}	div64(a,b,tmp);	if (tmp[0] || tmp[1] || tmp[2] || tmp[3]) {		while (i && tmp[3] >= 0) {			i--;			shift_left(tmp);		}		if (tmp[3] >= 0)			set_DE();	} else		i = 0;	if (i>0x7fff) {		set_OE();		return;	}	if (tmp[0] || tmp[1])		set_PE();	result->exponent = i | sign;	result->a = tmp[2];	result->b = tmp[3];}