| #include "f2c.h" | |
| #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); | |
| } |