ref: 95b60462d104de5f64bdf5cfba9a1ffab6e77e73
dir: /libnpe/log2.c/
#include <math.h> #include "_npe.h" double log2(double x) { if(x == 0) return -hugeD; if(x < 0 || isNaN(x)) return NaN(); return log(x)*ln2o1; } float log2f(float x) { if(x == 0) return -hugeF; return log2(x); }