www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.announce - LDC 1.25.0

reply kinke <noone nowhere.com> writes:
Glad to announce LDC 1.25 - some highlights:

- Based on D 2.095.1.
- LLVM for prebuilt packages bumped to v11.0.1; support added for 
LLVM 11.1 and upcoming 12.0.
- Profile/trace LDC invocations via --ftime-trace.
- New Windows installer and native 'Apple silicon' package.
- New experimental template emission scheme for 
-linkonce-templates. This option can significantly accelerate 
compilation times for optimized builds (e.g., 56% faster on my 
box when compiling the optimized Phobos unittests).

Full release log and downloads: 
https://github.com/ldc-developers/ldc/releases/tag/v1.25.0

Thanks to all contributors & sponsors!
Feb 21 2021
next sibling parent reply Dennis <dkorpel gmail.com> writes:
Great stuff, thanks!

On Sunday, 21 February 2021 at 18:26:38 UTC, kinke wrote:

 - Profile/trace LDC invocations via --ftime-trace.


Is there more info on this? I tried it on a simple file, it 
generates a large json file.
Can this be inspected to reduce compile times? The changelog and 
pull request do not reveal much info on how to use it for the 
uninformed.
Feb 21 2021
parent reply kinke <noone nowhere.com> writes:
On Sunday, 21 February 2021 at 21:58:48 UTC, Dennis wrote:

 On Sunday, 21 February 2021 at 18:26:38 UTC, kinke wrote:

 - Profile/trace LDC invocations via --ftime-trace.


 Is there more info on this? I tried it on a simple file, it 
 generates a large json file.
 Can this be inspected to reduce compile times? The changelog 
 and pull request do not reveal much info on how to use it for 
 the uninformed.


See Johan's comment here: 
https://forum.dlang.org/post/usyrbgwzzwxnzzhqergx forum.dlang.org
Feb 21 2021
parent reply Johan Engelen <j j.nl> writes:
On Monday, 22 February 2021 at 07:20:16 UTC, kinke wrote:

 On Sunday, 21 February 2021 at 21:58:48 UTC, Dennis wrote:

 On Sunday, 21 February 2021 at 18:26:38 UTC, kinke wrote:

 - Profile/trace LDC invocations via --ftime-trace.


 Is there more info on this? I tried it on a simple file, it 
 generates a large json file.
 Can this be inspected to reduce compile times? The changelog 
 and pull request do not reveal much info on how to use it for 
 the uninformed.


 See Johan's comment here: 
 https://forum.dlang.org/post/usyrbgwzzwxnzzhqergx forum.dlang.org


Thanks kinke.

This article explains the basics: 
https://www.snsystems.com/technology/tech-blog/clang-time-trace-feature

I'm aware there is very little documentation about this... I lack 
the time to write up more details and promote it better. Now that 
it's released, I hope promotion can be picked up by LDC's users. 
Here is an example of how it can help:
https://github.com/dlang/phobos/pull/7676#issuecomment-715373535

There is definitely room for improvement, but it requires user 
feedback and consideration of their different use cases.

-Johan
Feb 22 2021
parent reply Dennis <dkorpel gmail.com> writes:
On Monday, 22 February 2021 at 11:57:46 UTC, Johan Engelen wrote:

 This article explains the basics: 
 https://www.snsystems.com/technology/tech-blog/clang-time-trace-feature


Thank you! I opened the trace of my project in chrome://tracing 
and found that the majority of semantic analysis was spent on 
instantiations of `std.conv: text`. I replaced them and 
compilation time went down from 2.1 to 1.6 seconds, which I think 
is a big win!


 There is definitely room for improvement, but it requires user 
 feedback and consideration of their different use cases.


I'm already happy with what is there, but so far the most 
annoying part is that chrome's viewer is terribly slow and 
unresponsive. It can easily take a minute to load a trace, after 
which it runs at 1 frame per second, so I'm looking for an 
alternative.

The article mentions Speedscope, but my first impression isn't 
that great: it's still slow, and the interface is not 
self-explanatory unlike Chrome's.

In the PR you mentioned tracy*, but I'm still looking at how to 
compile it for Linux since the release only seems to include 
Windows binaries. I guess I'll try it out on Windows first.

*https://github.com/ldc-developers/ldc/pull/3624#issuecomment-735446453
Feb 25 2021
parent reply Mathias LANG <geod24 gmail.com> writes:
On Thursday, 25 February 2021 at 19:57:04 UTC, Dennis wrote:

 In the PR you mentioned tracy*, but I'm still looking at how to 
 compile it for Linux since the release only seems to include 
 Windows binaries. I guess I'll try it out on Windows first.

 *https://github.com/ldc-developers/ldc/pull/3624#issuecomment-735446453


If it's the regular client, then just cd to 
https://github.com/wolfpld/tracy/tree/master/profiler/build/unix 
and run `make`. We use it on Linux without problem, but the 
profiler crashes on Mac OSX ATM.
Feb 25 2021
parent Dennis <dkorpel gmail.com> writes:
On Friday, 26 February 2021 at 01:10:48 UTC, Mathias LANG wrote:

 If it's the regular client, then just cd to 
 https://github.com/wolfpld/tracy/tree/master/profiler/build/unix and run
`make`. We use it on Linux without problem, but the profiler crashes on Mac OSX
ATM.


I had to `sudo apt install libcapstone-dev`, but after that it 
worked!
So for others, my current Debian-linux setup looks like this:

```

git clone https://github.com/wolfpld/tracy


cd tracy/import-chrome/build/unix/
make

anywhere
sudo cp import-chrome-release /usr/bin/import-chrome


cd ../../../
cd profiler/build/unix/
make
sudo cp Tracy-release /usr/bin/tracy
```

Now add these settings to dub.sdl (either temporarily for all 
builds, or inside a specific configuration):
```
dflags "--ftime-trace" platform="ldc"
dflags "--ftime-trace-file=./my-trace.json" platform="ldc"
postBuildCommands "import-chrome ./my-trace.json 
./my-trace.tracy" platform="ldc"

```

Then build and open the trace:
```
dub build --compiler=ldc2
tracy my-trace.tracy
```
And enjoy 60 fps!
Feb 26 2021
prev sibling next sibling parent reply Steven Schveighoffer <schveiguy gmail.com> writes:
On 2/21/21 1:26 PM, kinke wrote:

 Glad to announce LDC 1.25 - some highlights:
 
 - Based on D 2.095.1.
 - LLVM for prebuilt packages bumped to v11.0.1; support added for LLVM 
 11.1 and upcoming 12.0.
 - Profile/trace LDC invocations via --ftime-trace.
 - New Windows installer and native 'Apple silicon' package.
 - New experimental template emission scheme for -linkonce-templates. 
 This option can significantly accelerate compilation times for optimized 
 builds (e.g., 56% faster on my box when compiling the optimized Phobos 
 unittests).


This is cool! Can you describe what it means? The option name isn't 
telling me anything obvious.


 
 Full release log and downloads: 
 https://github.com/ldc-developers/ldc/releases/tag/v1.25.0
 
 Thanks to all contributors & sponsors!


That's a first -- I haven't seen a 2.095.1 announcement yet (just the beta)

-Steve
Feb 21 2021
parent kinke <noone nowhere.com> writes:
On Monday, 22 February 2021 at 02:32:22 UTC, Steven Schveighoffer 
wrote:

 This is cool! Can you describe what it means? The option name 
 isn't telling me anything obvious.


Please see the changelog for more details.


 That's a first -- I haven't seen a 2.095.1 announcement yet 
 (just the beta)


Hmm, maybe Martin forgot the announcement or hasn't gotten to it 
yet; it's available on dlang.org.
Feb 21 2021
prev sibling next sibling parent Mathias LANG <geod24 gmail.com> writes:
On Sunday, 21 February 2021 at 18:26:38 UTC, kinke wrote:

 Glad to announce LDC 1.25 - some highlights:

 - Based on D 2.095.1.
 - LLVM for prebuilt packages bumped to v11.0.1; support added 
 for LLVM 11.1 and upcoming 12.0.
 - Profile/trace LDC invocations via --ftime-trace.
 - New Windows installer and native 'Apple silicon' package.
 - New experimental template emission scheme for 
 -linkonce-templates. This option can significantly accelerate 
 compilation times for optimized builds (e.g., 56% faster on my 
 box when compiling the optimized Phobos unittests).

 Full release log and downloads: 
 https://github.com/ldc-developers/ldc/releases/tag/v1.25.0

 Thanks to all contributors & sponsors!


Amazing! We were really looking forward to this release, as it 
makes both Alpine Linux and `-preview=in` finally usable for us, 
and will allow us to build some useful tools on top of the GC. 
Many thanks for your continuous efforts in maintaining the 
project!
Feb 22 2021
prev sibling parent reply "H. S. Teoh" <hsteoh quickfur.ath.cx> writes:
On Sun, Feb 21, 2021 at 06:26:38PM +0000, kinke via Digitalmars-d-announce
wrote:

 Glad to announce LDC 1.25 - some highlights:
 
 - Based on D 2.095.1.


Awesome!!  Thanks to everyone in the LDC team who made this release
possible.


[...]

 - New experimental template emission scheme for -linkonce-templates.
 This option can significantly accelerate compilation times for
 optimized builds (e.g., 56% faster on my box when compiling the
 optimized Phobos unittests).


[...]

Tested this on one of my projects yesterday. For -O3, it reduced compile
time by about ~26%.  For -O, it reduced compile time by about 24%.  Not
as much as I'd hoped, but still pretty big reductions.

For non-optimized builds, it reduced compile times by only 1-2% (pretty
insignificant).


T

-- 
The easy way is the wrong way, and the hard way is the stupid way. Pick one.
Feb 23 2021
parent reply kinke <noone nowhere.com> writes:
On Tuesday, 23 February 2021 at 18:19:09 UTC, H. S. Teoh wrote:

 Tested this on one of my projects yesterday. For -O3, it 
 reduced compile time by about ~26%.  For -O, it reduced compile 
 time by about 24%.  Not as much as I'd hoped, but still pretty 
 big reductions.


Thx for some numbers. [Note that -O == -O3 == -O4 == -O5, they 
are all the same (at least for now), contrary to what you might 
read somewhere.]
A reduction by 25%, i.e., a 1.33x speed-up, for code that is 
guaranteed to be at least as fast as before (higher cross-module 
inlining potential) isn't too bad, aye? :)


 For non-optimized builds, it reduced compile times by only 1-2% 
 (pretty insignificant).


I find it rather interesting that it isn't any slower. Compiling 
debug Phobos all-at-once took 67% longer on my box (and increased 
the static lib size by 76%). Without -O, I've only seen some 
improvements with `-unittest`.

Some more numbers on my box:

https://github.com/ldc-developers/ldc/pull/3600#issuecomment-729116599
https://github.com/ldc-developers/ldc/pull/3422#issuecomment-661386233
Feb 23 2021
parent "H. S. Teoh" <hsteoh quickfur.ath.cx> writes:
On Tue, Feb 23, 2021 at 07:32:13PM +0000, kinke via Digitalmars-d-announce
wrote:

 On Tuesday, 23 February 2021 at 18:19:09 UTC, H. S. Teoh wrote:

 Tested this on one of my projects yesterday. For -O3, it reduced
 compile time by about ~26%.  For -O, it reduced compile time by
 about 24%.  Not as much as I'd hoped, but still pretty big
 reductions.


 
 Thx for some numbers. [Note that -O == -O3 == -O4 == -O5, they are all
 the same (at least for now), contrary to what you might read
 somewhere.] A reduction by 25%, i.e., a 1.33x speed-up, for code that
 is guaranteed to be at least as fast as before (higher cross-module
 inlining potential) isn't too bad, aye? :)


Yeah actually it's pretty good.  It's only that my expectations were a
bit high when you reported 50+% reductions in compile times. :-)



 For non-optimized builds, it reduced compile times by only 1-2%
 (pretty insignificant).


 
 I find it rather interesting that it isn't any slower. Compiling debug
 Phobos all-at-once took 67% longer on my box (and increased the static
 lib size by 76%). Without -O, I've only seen some improvements with
 `-unittest`.


[...]

Interesting indeed. I just did a quick test with -unittest, and got
these numbers:

-unittest:				15.9 sec
-unittest -linkonce-templates:		22.3 sec
-unittest -O:				54.4 sec
-unittest -O -linkonce-templates:	40.7 sec

Apparently with -unittest it *does* run slower without -O. But with -O,
it does run faster.


T

-- 
It won't be covered in the book. The source code has to be useful for
something, after all. -- Larry Wall
Feb 23 2021