Thanks, nice result, I'll try to run the performance benchmarks that are
coming with libstdc++ to see if they spot anything.
That's tests in testsuite/performance folder in case you want to have a
try yourself.
François
On 18/01/2024 10:26, Huanghui Nie wrote:
Yes, I have. I did a
Yes, I have. I did a benchmark today.
The conclusion is: the time consumption can be reduced by 0.4% ~ 1.2% when
unordered_set erase(begin()), and 1.2% ~ 2.4% when erase(begin(), end()).
My test environment:
CPU: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz, 2393.365 MHz, 56 CPUs
MEM: 256G
OS:
Hi
Looks like a great finding to me, this is indeed a useless check, thanks!
Have you any figures on the performance enhancement ? It might help to
get proper approval as gcc is currently in dev stage 4 that is to say
only bug fixes normally.
François
On 17/01/2024 09:11, Huanghui Nie
I'm sorry for CC the gcc@ list. Waiting for your review results there.
Thanks.
2024年1月17日(水) 16:18 Jonathan Wakely :
>
>
> On Wed, 17 Jan 2024, 08:14 Huanghui Nie via Gcc, wrote:
>
>> Thanks. Done.
>>
>
> And don't CC the main gcc@ list, that's not for patch discussion. And if
> you CC the
On Wed, 17 Jan 2024, 08:14 Huanghui Nie via Gcc, wrote:
> Thanks. Done.
>
And don't CC the main gcc@ list, that's not for patch discussion. And if
you CC the right list, you don't need to CC the individual maintainers.
Anyway, it's on the right list now so we'll review it there, thanks.
>
Thanks. Done.
2024年1月17日(水) 12:39 Sam James :
>
> Huanghui Nie writes:
>
> > Hi.
>
> Please CC the libstdc++ LM for libstdc++ patches, per
>
> https://gcc.gnu.org/onlinedocs/libstdc++/manual/appendix_contributing.html#list.patches
> .
>
> > [...]
>
>
Hi.
When I implemented a hash table with reference to the C++ STL, I found that
when the hash table in the C++ STL deletes elements, if the first element
deleted is the begin element, the before begin node is repeatedly assigned.
This creates unnecessary performance overhead.
First, let’s see
Huanghui Nie writes:
> Hi.
Please CC the libstdc++ LM for libstdc++ patches, per
https://gcc.gnu.org/onlinedocs/libstdc++/manual/appendix_contributing.html#list.patches.
> [...]
Hi.
When I implemented a hash table with reference to the C++ STL, I found that
when the hash table in the C++ STL deletes elements, if the first element
deleted is the begin element, the before begin node is repeatedly assigned.
This creates unnecessary performance overhead.
First, let’s see
