#define _GNU_SOURCE #include #include #include "weak_alias.h" //#include "libc.h" double exp10(double x) { static const double p10[] = { 1e-15, 1e-14, 1e-13, 1e-12, 1e-11, 1e-10, 1e-9, 1e-8, 1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, 1e12, 1e13, 1e14, 1e15 }; double n, y = modf(x, &n); union {double f; uint64_t i;} u = {n}; /* fabs(n) < 16 without raising invalid on nan */ if ((u.i>>52 & 0x7ff) < 0x3ff+4) { if (!y) return p10[(int)n+15]; y = exp2(3.32192809488736234787031942948939 * y); return y * p10[(int)n+15]; } return pow(10.0, x); } weak_alias(exp10, pow10);