Why is D significantly slower than C# in this instance?

[H. S. Teoh]

On Mon, Apr 10, 2023 at 09:18:59PM +0000, Artjom via Digitalmars-d wrote:
> I have written this simple bruteforce algorithm that finds max sum of
> subsequence in some sequence, both in C# and D. And when the size of
> array is 1000000 elements - D is 20 seconds lated. Why?

Which compiler are you using and what are the compiler options?


> D code (algorithm):
> '
>     public int solveBruteForce()
>     {
>         int currMax = arr[0], currSum;
>         foreach (_; arr)
>         {
>             currSum = 0;
>             foreach (int el; arr)
>             {
>                 currSum += el;
>                 currMax = max(currSum, currMax);
>             }
>         }
> 
>         return currMax;
>     }
> '
> D code (measuring exec time):
> '
>     double measureTime()
>     {
>         StopWatch sw;
>         sw.start();
>         solveDynamic();

This doesn't call the above function solveBruteForce. What's the
definition of solveDynamic?


>         double sec = (to!double(sw.peek.total!"msecs") / 1000) +
> (to!double(sw.peek.total!"usecs") / 1000000);
>         return sec;
>     }
[...]


T

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