opencv/3rdparty/lapack/pow_ii.c

28 lines
436 B
C

#include "clapack.h"
integer pow_ii(integer *ap, integer *bp)
{
integer pow, x, n;
unsigned long u;
x = *ap;
n = *bp;
if (n <= 0) {
if (n == 0 || x == 1)
return 1;
return x != -1 ? 0 : (n & 1) ? -1 : 1;
}
u = n;
for(pow = 1; ; )
{
if(u & 01)
pow *= x;
if(u >>= 1)
x *= x;
else
break;
}
return(pow);
}