[unix-history] / lib / libF77 / pow_di.c

#include "f2c.h"

#ifdef KR_headers
double pow_di(ap, bp) doublereal *ap; integer *bp;
#else
double pow_di(doublereal *ap, integer *bp)
#endif
{
double pow, x;
integer n;

pow = 1;
x = *ap;
n = *bp;

if(n != 0)
	{
	if(n < 0)
		{
		n = -n;
		x = 1/x;
		}
	for( ; ; )
		{
		if(n & 01)
			pow *= x;
		if(n >>= 1)
			x *= x;
		else
			break;
		}
	}
return(pow);
}
Commit	Line	Data
547779a8 WH	1	#include "f2c.h"
	2
	3	#ifdef KR_headers
	4	double pow_di(ap, bp) doublereal ap; integer bp;
	5	#else
	6	double pow_di(doublereal ap, integer bp)
	7	#endif
	8	{
	9	double pow, x;
	10	integer n;
	11
	12	pow = 1;
	13	x = *ap;
	14	n = *bp;
	15
	16	if(n != 0)
	17	{
	18	if(n < 0)
	19	{
	20	n = -n;
	21	x = 1/x;
	22	}
	23	for( ; ; )
	24	{
	25	if(n & 01)
	26	pow *= x;
	27	if(n >>= 1)
	28	x *= x;
	29	else
	30	break;
	31	}
	32	}
	33	return(pow);
	34	}