Disappointing math performance compared to GDC

Trass3r via digitalmars-d-ldc digitalmars-d-ldc at puremagic.com
Wed Oct 8 08:32:45 PDT 2014


>> * Never ever use std.math as you will get the insane 80-bit
>> functions.
>
> What can one use to avoid this, and use the 64-bit numbers.

Note that this is less of an issue for x86 code using x87 by 
default.
On x64 though this results in really bad code switching between 
SSE and x87 registers.
But vectorization is usually killed in any case.

I personally use core.stdc.tgmath atm.

>> * [...]
> Is there any work to handle the above? Does GDC actually suffer 
> the same (or analogous) issues?

I think there have been threads debating the unreasonable 'real 
by default' attitude.
No clue if there's any result.

And core.math is a big question mark to me.

I don't know about gdc. Its runtime doesn't look much different.


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