cfloat.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <errno.h>
   4 #include <math.h>
   5
   6 #include "cfloat.h"
   7
   8 int double_format(char *buf, const char *fmt, double val)
   9 {
  10         if (buf == NULL)
  11                 return snprintf(NULL, 0, fmt, val);
  12         return sprintf(buf, fmt, val);
  13 }
  14
  15 double double_signum(double val)
  16 {
  17         if (signbit(val))
  18                 return -1;
  19         return 1;
  20 }
  21
  22 int double_classify(double val)
  23 {
  24         switch (fpclassify(val)) {
  25         case FP_INFINITE:
  26                 return 0;
  27         case FP_NAN:
  28                 return 1;
  29         case FP_NORMAL:
  30                 return 2;
  31         case FP_SUBNORMAL:
  32                 return 3;
  33         case FP_ZERO:
  34                 return 4;
  35         }
  36
  37         return -1;
  38 }