4.3BSD - /usr/src/new/icon/rt/pow.c

   1: #include   <errno.h>
   2: int errno;
   3: double log(), exp();
   4: /*
   5:  * pow - calculate arg1^arg2.
   6:  */
   7: double
   8: pow(arg1,arg2)
   9: double arg1, arg2;
  10:    {
  11:    double temp;
  12:    long l;
  13: 
  14:    if(arg1 <= 0.) {
  15:       if(arg1 == 0.) {
  16:          if(arg2 <= 0.)
  17:             goto domain;
  18:          return(0.);
  19:       }
  20:       l = arg2;
  21:       if(l != arg2)
  22:          goto domain;
  23:       temp = exp(arg2 * log(-arg1));
  24:       if(l & 1)
  25:          temp = -temp;
  26:       return(temp);
  27:    }
  28:    return(exp(arg2 * log(arg1)));
  29: 
  30: domain:
  31:    errno = EDOM;
  32:    return(0.);
  33:    }

Defined functions

Defined variables