Re: Help to understanding a case of innefective allocation sinking
- From: Alexander Gall <alexander.gall@xxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Fri, 12 Dec 2014 14:16:59 +0100
On Fri, Dec 12, 2014 at 12:46 PM, Mike Pall <mike-1412@xxxxxxxxxx> wrote:
> Alexander Gall wrote:
>> The main question is whether the code can be written in a manner that
>> avoids this effect.
>
> local sum = ffi.new("int64_t[1]")
> ...
> sum[0] = sum[0] + ...
>
> You get an extra store on every inner loop iteration, but no more
> allocations on every outer loop iteration. Whether that's faster
> or not depends on the iteration count of the inner loop vs. the
> outer loop.
Thanks for detailed explanation. I'm actually using this method in
other parts of my code but failed to realise that it can be applied
here as well.
--
Alex
Other related posts:
