std.d.lexer performance (WAS: std.d.lexer : voting thread)

[Dmitry Olshansky]

11-Oct-2013 14:58, Jonathan M Davis пишет:
> On Friday, October 11, 2013 13:53:29 Dmitry Olshansky wrote:
>> 11-Oct-2013 13:07, Jonathan M Davis пишет:
>>> On Friday, October 11, 2013 12:56:14 Dmitry Olshansky wrote:
>>>> 04-Oct-2013 15:28, Brian Schott пишет:
>>>>> On Thursday, 3 October 2013 at 20:11:02 UTC, Andrei Alexandrescu wrote:
>>>>>> I see we're considerably behind dmd. If improving performance would
>>>>>> come at the price of changing the API, it may be sensible to hold off
>>>>>> adoption for a bit.
>>>>>>
>>>>>> Andrei
>>>>>
>>>>> The old benchmarks measured total program run time. I ran a new set of
>>>>> benchmarks, placing stopwatch calls around just the lexing code to
>>>>> bypass any slowness caused by druntime startup. I also made a similar
>>>>> modification to DMD.
>>>>>
>>>>> Here's the result:
>>>>>
>>>>> https://raw.github.com/Hackerpilot/hackerpilot.github.com/master/experim
>>>>> en
>>>>> tal/std_lexer/images/times5.png
>>>>>
>>>>>
>>>>> I suspect that I've made an error in the benchmarking due to how much
>>>>> faster std.d.lexer is than DMD now, so I've uploaded what I have to
>>>>> Github.
>>>>>
>>>>> https://github.com/Hackerpilot/lexerbenchmark
>>>>
>>>> I'm suspicious of:
>>>> printf("%s\t%f\n", srcname, (total / 200.0) / (1000 * 100));
>>>>
>>>> Plus I think clock_gettime often has too coarse resolution (I'd use
>>>> gettimeofday as more reliable).
>>>> Also check core\time.d  TickDuration.currSystemTick as it uses
>>>> CLOCK_MONOTONIC on *nix. You should do the same to make timings
>>>> meaningful.
>>>
>>> Why not just use use std.datetime's benchmark or StopWatch? Though looking
>>> at lexerbenchmark.d it looks like he's using StopWatch rather than
>>> clock_gettime directly, and there are no printfs, so I don't know what
>>> code you're referring to here. From the looks of it though, he's
>>> basically reimplemented std.datetime.benchmark in benchmarklexer.d and
>>> probably should have just used benchmark instead.
>>
>> Cause it's C++ damn it! ;)
>
> Your comments would make perfect sense for C++, but lexerbenchmark.d is in D.
> And I don't know what else you could be talking about, because that's all I
> see referenced here.

I was looking at dmd.diff actually in linked repo.
https://github.com/Hackerpilot/lexerbenchmark/blob/master/dmd.diff

lexerbenchmark.d uses StopWatch.

>
> - Jonathan M Davis
>


-- 
Dmitry Olshansky