DConf 2013 Day 3 Talk 4: LDC by David Nadlinger

[jerro]

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quite outdated)