#include #include int __fpclassify(double x) { union {double f; uint64_t i;} u = {x}; int e = u.i>>52 & 0x7ff; if (!e) return u.i<<1 ? FP_SUBNORMAL : FP_ZERO; if (e==0x7ff) return u.i<<12 ? FP_NAN : FP_INFINITE; return FP_NORMAL; }