D code optimization

[Brad Anderson via Digitalmars-d-learn]

On Thursday, 22 September 2016 at 16:09:49 UTC, Sandu wrote:
> It is often being claimed that D is at least as fast as C++.
> Now, I am fairly new to D. But, here is an example where I want 
> to see how can this be made possible.
>
> So far my C++ code compiles in ~850 ms.
> While my D code runs in about 2.1 seconds.
>
> [snip]

Just a small tip that applies to both D and C++ in that code. You 
can use a static array rather than a dynamically allocated array 
in the loop (enum n = 252; then double[n+1] call; in D). You can 
also use "double[n+1] call = void;" to mimic C++'s behavior of 
uninitialized memory.

Use GDC or LDC when doing performance related work as they 
generate faster code typically. I'd be surprised if the C++ and D 
code asm wasn't nearly identical for a big chunk of this code 
when using GCC/GDC or Clang/LDC.