It seems like every DMD release makes compilation slower. This time I see 10.8s vs 7.8s on my little project. I know this is generally least of concern, and D1's lighting-fast times are long gone, but since Walter often claims D's superior compilation speeds, maybe some profiling is in order ?

On 3/29/2015 4:14 PM, Martin Krejcirik wrote:
> It seems like every DMD release makes compilation slower. This time I see 10.8s
> vs 7.8s on my little project. I know this is generally least of concern, and
> D1's lighting-fast times are long gone, but since Walter often claims D's
> superior compilation speeds, maybe some profiling is in order ?

Sigh. Two things happen constantly:

1. object file sizes creep up
2. compilation speed slows down

It's like rust on your car. Fixing it requires constant vigilance.

On Monday, 30 March 2015 at 00:12:09 UTC, Walter Bright wrote:
> On 3/29/2015 4:14 PM, Martin Krejcirik wrote:
>> It seems like every DMD release makes compilation slower. This time I see 10.8s
>> vs 7.8s on my little project. I know this is generally least of concern, and
>> D1's lighting-fast times are long gone, but since Walter often claims D's
>> superior compilation speeds, maybe some profiling is in order ?
>
> Sigh. Two things happen constantly:
>
> 1. object file sizes creep up
> 2. compilation speed slows down
>
> It's like rust on your car. Fixing it requires constant vigilance.

would having benchmarks help keep this under control/make regressions easier to find?

On 3/29/2015 5:14 PM, weaselcat wrote:
> would having benchmarks help keep this under control/make regressions easier to
> find?

benchmarks would help.

On 03/30/2015 01:14 AM, Martin Krejcirik wrote:
> It seems like every DMD release makes compilation slower. This time I see 10.8s vs 7.8s on my little project. I know this is generally least of concern, and D1's lighting-fast times are long gone, but since Walter often claims D's superior compilation speeds, maybe some profiling is in order ?

25% slowdown is severe, can you share the project and probably file a bug report?

Is it only DMD compile time or DMD + ld ? ld can be very slow sometimes.

2015-03-30 1:14 GMT+02:00 Martin Krejcirik via Digitalmars-d < digitalmars-d@puremagic.com>:

> It seems like every DMD release makes compilation slower. This time I see 10.8s vs 7.8s on my little project. I know this is generally least of concern, and D1's lighting-fast times are long gone, but since Walter often claims D's superior compilation speeds, maybe some profiling is in order ?
>

Here is one example:

Orange d5b2e0127c67f50bd885ee43a7dd61dd418b1661
https://github.com/jacob-carlborg/orange.git
make

2.065.0
real    0m9.028s
user    0m7.972s
sys     0m0.940s

2.066.1
real    0m10.796s
user    0m9.629s
sys     0m1.056s

2.067.0
real    0m13.543s
user    0m12.097s
sys     0m1.348s

On 2015-03-30 18:09, Martin Krejcirik wrote:
> Here is one example:
>
> Orange d5b2e0127c67f50bd885ee43a7dd61dd418b1661
> https://github.com/jacob-carlborg/orange.git
> make
>
> 2.065.0
> real    0m9.028s
> user    0m7.972s
> sys     0m0.940s
>
> 2.066.1
> real    0m10.796s
> user    0m9.629s
> sys     0m1.056s
>
> 2.067.0
> real    0m13.543s
> user    0m12.097s
> sys     0m1.348s

These are the timings for compiling the unit tests without linking. It passes all the files to DMD in one command. The make file invokes DMD once per file.

1.076
real	0m0.212s
user	0m0.187s
sys	0m0.022s

2.065.0
real	0m0.426s
user	0m0.357s
sys	0m0.065s

2.066.1
real	0m0.470s
user	0m0.397s
sys	0m0.064s

2.067.0
real	0m0.510s
user	0m0.435s
sys	0m0.074s

It might not be fair to compare with D1 since it's not exactly the same code.

-- 
/Jacob Carlborg

On Sunday, 29 March 2015 at 23:14:31 UTC, Martin Krejcirik wrote:
> It seems like every DMD release makes compilation slower. This time I see 10.8s vs 7.8s on my little project. I know this is generally least of concern, and D1's lighting-fast times are long gone, but since Walter often claims D's superior compilation speeds, maybe some profiling is in order ?

I'm finding memory usage the biggest problem for me. 3s speed increase is not nice but an increase of 500MB RAM usage with DMD 2.067 over 2.066 means I can no longer build one of my projects.

bye,
lobo

On Monday, 30 March 2015 at 22:39:51 UTC, lobo wrote:
> On Sunday, 29 March 2015 at 23:14:31 UTC, Martin Krejcirik wrote:
>> It seems like every DMD release makes compilation slower. This time I see 10.8s vs 7.8s on my little project. I know this is generally least of concern, and D1's lighting-fast times are long gone, but since Walter often claims D's superior compilation speeds, maybe some profiling is in order ?
>
> I'm finding memory usage the biggest problem for me. 3s speed increase is not nice but an increase of 500MB RAM usage with DMD 2.067 over 2.066 means I can no longer build one of my projects.
>
> bye,
> lobo

I should add that I am on a 32-bit machine with 4GB RAM. I just ran some tests measuring RAM usage:

DMD 2.067 ~4.2GB (fails here so not sure of the full amount required)
DMD 2.066 ~3.7GB (maximum)
DMD 2.065 ~3.1GB (maximum)

It was right on the edge with 2.066 anyway but this trend of more RAM usage seems to also be occurring with each DMD release.

bye,
lobo