File indexing completed on 2024-04-06 12:31:44
0001 #include <cmath>
0002 #include <cstdio>
0003 #include <iostream>
0004
0005
0006 inline double fastPow(double a, double b) {
0007 union {
0008 double d;
0009 int x[2];
0010 } u = { a };
0011 u.x[1] = (int)(b * (u.x[1] - 1072632447) + 1072632447);
0012 u.x[0] = 0;
0013 return u.d;
0014 }
0015
0016
0017
0018 int main() {
0019 constexpr double Safety = 0.9;
0020 double eps=1.e-5;
0021 const float cut = std::pow(10.f/Safety,5.f);
0022 double accMin = eps/cut;
0023 std::cout << "eps/cut/accMin " << eps << " " << cut << " " << accMin
0024 << std::endl;
0025 for (double acc=accMin; acc<eps; acc*=10.)
0026 std::cout << acc << " " << std::pow(eps/acc,0.2f) << " " << fastPow(eps/acc,0.2f) << std::endl;
0027
0028 return 0;
0029
0030
0031 }
