cantera/ext/f2c_libs/pow_qq.c
2008-02-05 23:36:07 +00:00

39 lines
560 B
C

#include "f2c.h"
//#ifdef __cplusplus
//extern "C" {
//#endif
//#ifdef KR_headers
//longint pow_qq(ap, bp) longint *ap, *bp;
//#else
longint pow_qq(longint *ap, longint *bp)
//#endif
{
longint pow, x, n;
unsigned long long u; /* system-dependent */
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);
}
//#ifdef __cplusplus
//}
//#endif