Slow performance compared to C++, ideas?

[finalpatch]

Hi Walter,

Thanks for the reply. I have already tried these flags. However, 
DMD's codegen is lagging behind GCC and LLVM at the moment, so 
even with these flags, the runtime is ~10x longer than the C++ 
version compiled with clang++ (2sec with DMD, 200ms with clang++ 
on a Core2 Mac Pro). I know this is comparing apples to oranges 
though, that's why I was comparing GDC vs G++ and LDC vs Clang++.

On Friday, 31 May 2013 at 02:19:40 UTC, Walter Bright wrote:
> For max speed using dmd, use the flags:
>
>    -O -release -inline -noboundscheck
>
> The -inline is especially important.