Re: Speed of math function atan: comparison D and C++

[psychoticRabbit via Digitalmars-d-learn]

On Monday, 5 March 2018 at 06:01:27 UTC, J-S Caux wrote:

So the codes are trivial, simply some check of raw speed:

  double x = 0.0;

for (int a = 0; a < 1000000000; ++a) x += atan(1.0/(1.0 + sqrt(1.0 + a)));

for C++ and

  double x = 0.0;

for (int a = 0; a < 1_000_000_000; ++a) x += atan(1.0/(1.0 + sqrt(1.0 + a)));

for D. C++ exec takes 40 seconds, D exec takes 68 seconds.

should a be an int?

make it a double ;-)