Profiling DMD's Compilation Time with dmdprof

John Chapman johnch_atms at hotmail.com
Thu Nov 8 16:51:55 UTC 2018


On Thursday, 8 November 2018 at 14:33:34 UTC, Petar Kirov 
[ZombineDev] wrote:
> On Thursday, 8 November 2018 at 07:54:56 UTC, Manu wrote:
>> On Wed, Nov 7, 2018 at 10:30 PM Vladimir Panteleev via 
>> Digitalmars-d-announce <digitalmars-d-announce at puremagic.com> 
>> wrote:
>>>
>>> On Thursday, 8 November 2018 at 06:08:20 UTC, Vladimir 
>>> Panteleev wrote:
>>> > It was definitely about 4 seconds not too long ago, a few 
>>> > years at most.
>>>
>>> No, it's still 4 seconds.
>>>
>>> digger --offline --config-file=/dev/null -j auto -c 
>>> local.cache=none build     7.31s user 1.51s system 203% cpu 
>>> 4.340 total
>>>
>>> > It does seem to take more time now; I wonder why.
>>>
>>> If it takes longer, then it's probably because it's being 
>>> built in one CPU core, or in the release build.
>>
>> https://youtu.be/msWuRlD3zy0
>>
>> DMD only builds with one core, since it builds altogether.
>> And all builds are release builds... what good is a debug 
>> build? DMD
>> is unbelievably slow in debug. If it wasn't already slow 
>> enough... if
>> I try and build with a debug build, it takes closer to 5 
>> minutes.
>>
>> I suspect one part of the problem is that DMD used to be built 
>> with a C compiler, and now it's built with DMD... it really 
>> should be built with LDC at least?
>
> The problem definitely looks like is with your Windows. Perhaps 
> it's caused by an antivirus software? For the record on my 
> machine it's consistently below 4sec. See:
> https://asciinema.org/a/G5lLRPsLLMb5IaqPrmhZagop4

I don't think it's just *his* Windows - DMD builds on my Windows 
10 Core i3 laptop with anti-virus disabled in about 1m 40s too. 
And it's always taken about this long, even when the source was 
C++. I'm tempted to try it on Linux on the same machine to see 
what I'm missing out on.


More information about the Digitalmars-d-announce mailing list