freebsd-dev/contrib/libf2c/libF77/pow_ii.c

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1999-09-18 10:51:31 +00:00
#include "f2c.h"
#ifdef KR_headers
integer pow_ii(ap, bp) integer *ap, *bp;
#else
integer pow_ii(integer *ap, integer *bp)
#endif
{
integer pow, x, n;
unsigned long u;
x = *ap;
n = *bp;
if (n <= 0) {
if (n == 0 || x == 1)
return 1;
if (x != -1)
return x == 0 ? 1/x : 0;
n = -n;
}
u = n;
for(pow = 1; ; )
{
if(u & 01)
pow *= x;
if(u >>= 1)
x *= x;
else
break;
}
return(pow);
}