src/math/__fpclassify.c

   1 #include <math.h>
   2 #include <stdint.h>
   3
   4 int __fpclassify(double x)
   5 {
   6         union {double f; uint64_t i;} u = {x};
   7         int e = u.i>>52 & 0x7ff;
   8         if (!e) return u.i<<1 ? FP_SUBNORMAL : FP_ZERO;
   9         if (e==0x7ff) return u.i<<12 ? FP_NAN : FP_INFINITE;
  10         return FP_NORMAL;
  11 }