src/math/copysign.c

   1 #include "libm.h"
   2
   3 double copysign(double x, double y) {
   4         union {double f; uint64_t i;} ux={x}, uy={y};
   5         ux.i &= -1ULL/2;
   6         ux.i |= uy.i & 1ULL<<63;
   7         return ux.f;
   8 }