DMD is slow for matrix maths?

[H. S. Teoh via Digitalmars-d]

On Mon, Oct 26, 2015 at 02:37:16AM +0000, Etienne Cimon via Digitalmars-d wrote:
> I've been playing around with perf and my web server and found that
> the bottleneck is by far the math module of Botan:
> https://github.com/etcimon/botan/blob/master/source/botan/math/mp/mp_core.d
> 
> I'm probably a bit naive but I was wishing for some inlining to
> happen. I see LOTS of CPU time spent on "pop" instructions to return
> from a simple multiply function, and the pragma(inline, true) was
> refused on all of these.  So, should I wait for an inline? Should I
> import another library? Should I rewrite all the maths in assembly
> manually for each processor? Should I write another library that must
> be compiled with LDC/release for maths?
> 
> I think the best option would be for an inline feature in DMD that
> works, but I'm wondering what the stance is right now about the
> subject?

For an immediate solution to performance-related issues, I recommend
using GDC or LDC (with maximum optimization options) instead of DMD.

If you must use DMD, I recommend filing an enhancement request and
bothering Walter about it.


T

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