mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-24 21:09:39 +08:00
34 lines
449 B
C
34 lines
449 B
C
|
#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);
|
||
|
}
|