newlib/libc/stdlib/__adjust.c

   1 /*
   2  * return (*acc) scaled by 10**dexp.
   3  */
   4
   5 #include <_ansi.h>
   6 #include <reent.h>
   7 #include "std.h"
   8
   9 #define abs(x) (((x) < 0) ? -(x) : (x))
  10
  11 double
  12 __adjust (struct _reent *ptr,
  13         double *acc,
  14         int dexp,
  15         int sign)
  16      /* *acc    the 64 bit accumulator */
  17      /* dexp    decimal exponent       */
  18      /* sign    sign flag              */
  19 {
  20   double r;
  21
  22   if (dexp > MAXE)
  23     {
  24       _REENT_ERRNO(ptr) = ERANGE;
  25       return (sign) ? -HUGE_VAL : HUGE_VAL;
  26     }
  27   else if (dexp < MINE)
  28     {
  29       _REENT_ERRNO(ptr) = ERANGE;
  30       return 0.0;
  31     }
  32
  33   r = *acc;
  34   if (sign)
  35     r = -r;
  36   if (dexp == 0)
  37     return r;
  38
  39   if (dexp < 0)
  40     return r / __exp10 (abs (dexp));
  41   else
  42     return r * __exp10 (dexp);
  43 }