src/math/hypotf.c

   1 #include <math.h>
   2 #include <stdint.h>
   3
   4 float hypotf(float x, float y)
   5 {
   6         union {float f; uint32_t i;} ux = {x}, uy = {y}, ut;
   7         float_t z;
   8
   9         ux.i &= -1U>>1;
  10         uy.i &= -1U>>1;
  11         if (ux.i < uy.i) {
  12                 ut = ux;
  13                 ux = uy;
  14                 uy = ut;
  15         }
  16
  17         x = ux.f;
  18         y = uy.f;
  19         if (uy.i == 0xff<<23)
  20                 return y;
  21         if (ux.i >= 0xff<<23 || uy.i == 0 || ux.i - uy.i >= 25<<23)
  22                 return x + y;
  23
  24         z = 1;
  25         if (ux.i >= (0x7f+60)<<23) {
  26                 z = 0x1p90f;
  27                 x *= 0x1p-90f;
  28                 y *= 0x1p-90f;
  29         } else if (uy.i < (0x7f-60)<<23) {
  30                 z = 0x1p-90f;
  31                 x *= 0x1p90f;
  32                 y *= 0x1p90f;
  33         }
  34         return z*sqrtf((double)x*x + (double)y*y);
  35 }