Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Monday, 17 June 2013 at 15:41:24 UTC, nazriel wrote: On Monday, 17 June 2013 at 13:47:20 UTC, bearophile wrote: Andrei Alexandrescu: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ Slide 14: PFFT (SSE) seems slow on LDC2: if you can extract a small test case LLVM devs will appreciate a lot a bug report (they fixed many lacks of optimizations submitted by me). If you have a link to the PFFT code them maybe I can do that myself. I don't know what PFFT stands for (can't google it either, funny results shows up) but if it related to vectorization then maybe LDC has been slower because it was built against LLVM 3.3 while LLVM 3.4 brings more vector optimizations. Maybe all what has to be done, is rerunning benchmarks against LDC + LLVM 3.4 ? As far as I followed the LLVM commit list, the change is that the loop vectorizer is now enabled at -O2 (instead of -O3). I don't know the options David has used but I assume something like ldmd2 -O -inline -release. -O from ldmd2 maps to -O3 and therefore enables the loop vectorizer. Regards Kai Slide 25: Implicit invariants often hard to track down Then maybe it's a good idea to add such invariants to the dmd front-end code, even before its port to D. Bye, bearophile
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On 2013-06-17 14:25, Andrei Alexandrescu wrote: You know the drill! reddit: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ hackernews: https://news.ycombinator.com/item?id=5892652 facebook: https://www.facebook.com/dlang.org/posts/658638807483137 twitter: https://twitter.com/D_Programming/status/346598441230671873 youtube: http://youtube.com/watch?v=ntdKZWSiJdY David mentions in the talks that git submodules make it more complicated to do merges. I'm not sure I understand why. git submodules are just regular repositories that are included in other repositories. One can work on these repositories separately, then it shouldn't be much difference. -- /Jacob Carlborg
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On 2013-06-17 14:25, Andrei Alexandrescu wrote: You know the drill! reddit: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ hackernews: https://news.ycombinator.com/item?id=5892652 facebook: https://www.facebook.com/dlang.org/posts/658638807483137 twitter: https://twitter.com/D_Programming/status/346598441230671873 youtube: http://youtube.com/watch?v=ntdKZWSiJdY About the Mac OS X support. Is TLS the only problem on Snow Leopard? Have you considered moving the code dealing with TLS from the dynamic linker into the executable? -- /Jacob Carlborg
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
... slightly more serious response: really nice talk, David, and thanks for the mention of Dregs. :-)
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Monday, 17 June 2013 at 15:19:27 UTC, Andrej Mitrovic wrote: On 6/17/13, Andrei Alexandrescu seewebsiteforem...@erdani.org wrote: youtube: http://youtube.com/watch?v=ntdKZWSiJdY There seems to be some audio glitching every couple of seconds (at the beginning). I've noticed this in other videos as well. It's mostly minimal though, not much harm done. Yes, there were, and it was rather irritating for me as well. Actually, they even changed my wireless beltpack during the presentation, at the point where there is pretty much silence in the video and they cut to a shot of the bored audience. David
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
Great talk! Regarding the ci.lycus.org fleet, credit should definitely go to Adam Wilson (C# to D talk) and Kelly Wilson (same person who was present in the pie chart) too for providing many of the machines hooked up to the master node. The fleet doesn't do a whole lot of work most of the time, so if you have a project that 1) has a sane build system; 2) you're willing to respond to build failures on; 3) and is 'significant' enough, feel free to email me and I'll see what I can do. (By 'significant' I mean has enough impact to be useful for a reasonable amount of D programmers. This is of course pretty subjective, but we have to be a bit conservative about how many projects we add so that we don't end up having lots of stalled builds in the queue.)
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
Andrei Alexandrescu: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ Slide 14: PFFT (SSE) seems slow on LDC2: if you can extract a small test case LLVM devs will appreciate a lot a bug report (they fixed many lacks of optimizations submitted by me). If you have a link to the PFFT code them maybe I can do that myself. Slide 25: Implicit invariants often hard to track down Then maybe it's a good idea to add such invariants to the dmd front-end code, even before its port to D. Bye, bearophile
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On 6/17/13, Andrei Alexandrescu seewebsiteforem...@erdani.org wrote: youtube: http://youtube.com/watch?v=ntdKZWSiJdY There seems to be some audio glitching every couple of seconds (at the beginning). I've noticed this in other videos as well. It's mostly minimal though, not much harm done.
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Mon, 17 Jun 2013 11:19:14 -0400, Andrej Mitrovic andrej.mitrov...@gmail.com wrote: On 6/17/13, Andrei Alexandrescu seewebsiteforem...@erdani.org wrote: youtube: http://youtube.com/watch?v=ntdKZWSiJdY There seems to be some audio glitching every couple of seconds (at the beginning). I've noticed this in other videos as well. It's mostly minimal though, not much harm done. I noticed that during the conference. There were several talks where the mic was giving the AV guys trouble. Each of the speakers was using a clip-on remote mic. Of course, live, it wasn't as big a deal, as we could hear the person talking :) But it would be more glaring for the recording. I'm sure if there are any glitches that omit an important piece of the talk, point them out and the speaker and/or conference attendees can help discern what was being said. -Steve
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Monday, 17 June 2013 at 13:47:20 UTC, bearophile wrote: Andrei Alexandrescu: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ Slide 14: PFFT (SSE) seems slow on LDC2: if you can extract a small test case LLVM devs will appreciate a lot a bug report (they fixed many lacks of optimizations submitted by me). If you have a link to the PFFT code them maybe I can do that myself. I don't know what PFFT stands for (can't google it either, funny results shows up) but if it related to vectorization then maybe LDC has been slower because it was built against LLVM 3.3 while LLVM 3.4 brings more vector optimizations. Maybe all what has to be done, is rerunning benchmarks against LDC + LLVM 3.4 ? Slide 25: Implicit invariants often hard to track down Then maybe it's a good idea to add such invariants to the dmd front-end code, even before its port to D. Bye, bearophile
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Mon, 17 Jun 2013 17:41:22 +0200, nazriel wrote: On Monday, 17 June 2013 at 13:47:20 UTC, bearophile wrote: Andrei Alexandrescu: http://www.reddit.com/r/programming/comments/1gie4b/ dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ Slide 14: PFFT (SSE) seems slow on LDC2: if you can extract a small test case LLVM devs will appreciate a lot a bug report (they fixed many lacks of optimizations submitted by me). If you have a link to the PFFT code them maybe I can do that myself. I don't know what PFFT stands for (can't google it either, funny results shows up) but if it related to vectorization then maybe LDC has been slower because it was built against LLVM 3.3 while LLVM 3.4 brings more vector optimizations. Maybe all what has to be done, is rerunning benchmarks against LDC + LLVM 3.4 ? Slide 25: Implicit invariants often hard to track down Then maybe it's a good idea to add such invariants to the dmd front-end code, even before its port to D. Bye, bearophile My guess is Parallel Fast Fourier Transform.
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On 6/17/2013 8:35 AM, Steven Schveighoffer wrote: I'm sure if there are any glitches that omit an important piece of the talk, point them out and the speaker and/or conference attendees can help discern what was being said. I was saying flip that!.
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Monday, 17 June 2013 at 15:56:21 UTC, Justin Whear wrote: On Mon, 17 Jun 2013 17:41:22 +0200, nazriel wrote: On Monday, 17 June 2013 at 13:47:20 UTC, bearophile wrote: Andrei Alexandrescu: http://www.reddit.com/r/programming/comments/1gie4b/ dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ Slide 14: PFFT (SSE) seems slow on LDC2: if you can extract a small test case LLVM devs will appreciate a lot a bug report (they fixed many lacks of optimizations submitted by me). If you have a link to the PFFT code them maybe I can do that myself. I don't know what PFFT stands for (can't google it either, funny results shows up) but if it related to vectorization then maybe LDC has been slower because it was built against LLVM 3.3 while LLVM 3.4 brings more vector optimizations. Maybe all what has to be done, is rerunning benchmarks against LDC + LLVM 3.4 ? Slide 25: Implicit invariants often hard to track down Then maybe it's a good idea to add such invariants to the dmd front-end code, even before its port to D. Bye, bearophile My guess is Parallel Fast Fourier Transform. It's Pretty Fast Fourier Transform. The code is at https://github.com/jerro/pfft/tree/experimental (I linked to the experimental branch because master branch is quite outdated)
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Monday, 17 June 2013 at 15:19:27 UTC, Andrej Mitrovic wrote: There seems to be some audio glitching every couple of seconds (at the beginning). I've noticed this in other videos as well. It's mostly minimal though, not much harm done. https://www.youtube.com/watch?v=m6jsXQm5IrM#t=106s :-)
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
On Mon, 17 Jun 2013 08:25:50 -0400 Andrei Alexandrescu seewebsiteforem...@erdani.org wrote: You know the drill! reddit: http://www.reddit.com/r/programming/comments/1gie4b/dconf_2013_ldc_the_llvmbased_d_compiler_by_david/ hackernews: https://news.ycombinator.com/item?id=5892652 facebook: https://www.facebook.com/dlang.org/posts/658638807483137 twitter: https://twitter.com/D_Programming/status/346598441230671873 youtube: http://youtube.com/watch?v=ntdKZWSiJdY Andrei Torrents/links up: http://semitwist.com/download/misc/dconf2013/
Re: DConf 2013 Day 3 Talk 4: LDC by David Nadlinger
Am Mon, 17 Jun 2013 22:03:09 +0200 schrieb Joseph Rushton Wakeling joseph.wakel...@webdrake.net: On Monday, 17 June 2013 at 15:19:27 UTC, Andrej Mitrovic wrote: There seems to be some audio glitching every couple of seconds (at the beginning). I've noticed this in other videos as well. It's mostly minimal though, not much harm done. https://www.youtube.com/watch?v=m6jsXQm5IrM#t=106s :-) What's this wire doing here? It's dangerous! *pulls* -- Marco
