src/math/floorf.c

   1 #include "libm.h"
   2
   3 float floorf(float x)
   4 {
   5         union {float f; uint32_t i;} u = {x};
   6         int e = (int)(u.i >> 23 & 0xff) - 0x7f;
   7         uint32_t m;
   8
   9         if (e >= 23)
  10                 return x;
  11         if (e >= 0) {
  12                 m = 0x007fffff >> e;
  13                 if ((u.i & m) == 0)
  14                         return x;
  15                 FORCE_EVAL(x + 0x1p120f);
  16                 if (u.i >> 31)
  17                         u.i += m;
  18                 u.i &= ~m;
  19         } else {
  20                 FORCE_EVAL(x + 0x1p120f);
  21                 if (u.i >> 31 == 0)
  22                         u.i = 0;
  23                 else if (u.i << 1)
  24                         u.f = -1.0;
  25         }
  26         return u.f;
  27 }