similar to: Threading issues with CELT?

Hi, For those interested in reading more on CELT, here's another paper that just got accepted. That one focuses on the low-complexity mode and is based on 0.5.1. J.-M. Valin, T. B. Terriberry, G. Maxwell, A Full-Bandwidth Audio Codec with Low Complexity and Very Low Delay, Accepted for EUSIPCO 2009. http://people.xiph.org/~jm/papers/celt_eusipco2009.pdf Cheers, Jean-Marc

hi. i am currently adding celt support to netjack. very nice to see a free low-latency codec :) i currently dont require robustness against packet loss, because the sync code of netjack does not handle packet loss very gracefully. how much bandwidth is wasted for this feature ? is it sensible, to have the data downsampled berfore encoding , in order to reduce bandwidth ? i suspect that just

Hi, We are testing CELT 0.7.1 on an iPod touch and it seems we are already reaching the CPU limit of the machine for a 1 channel both directions stream. The CELT README says that the code should be compiled with fixed-point support, but it it not clear how it has to be used later on. We currently use celt_encode_float/celt_decode_float functions. Can we still use them with the fixed point version

> > <32 x float> takes up 8 SSE registers; you're likely running into > issues with register pressure. Does it work better if you use > something smaller like <4 x float>? > > Besides that, I don't see any obvious issues. > > -Eli You are right yes. The code works faster with <4 x float> types, with still works a bit slower than the scalar

Hi, Our DSL emit sub-optimal LLVM IR that we optimize later on (LLVM IR ==> LLVM IR) before dynamically compiling it with the JIT. We would like to simply follow what clang/clang++ does when compiling with -O1/-O2/-O3 options. Our strategy up to now what to look at the opt.cpp code and take part of it in order to implement our optimization code. It appears to be rather difficult to follow

Hi, Our DSL LLVM IR emitted code (optimized with -O3 kind of IR ==> IR passes) runs slower when executed with the LLVM 3.3 JIT, compared to what we had with LLVM 3.1. What could be the reason? I tried to play with TargetOptions without any success… Here is the kind of code we use to allocate the JIT: EngineBuilder builder(fResult->fModule);

On Tue, Jul 16, 2013 at 8:16 AM, Stéphane Letz <letz at grame.fr> wrote: > Hi, > > Our DSL emit sub-optimal LLVM IR that we optimize later on (LLVM IR ==> LLVM IR) before dynamically compiling it with the JIT. We would like to simply follow what clang/clang++ does when compiling with -O1/-O2/-O3 options. Our strategy up to now what to look at the opt.cpp code and take part of it

Le 5 juil. 2013 à 17:23, Arnold Schwaighofer <aschwaighofer at apple.com> a écrit : > > On Jul 5, 2013, at 9:50 AM, Stéphane Letz <letz at grame.fr> wrote: > >> >> Le 5 juil. 2013 à 04:11, Tobias Grosser <tobias at grosser.es> a écrit : >> >>> On 07/04/2013 01:39 PM, Stéphane Letz wrote: >>>> Hi, >>>>

Le 5 juil. 2013 à 04:11, Tobias Grosser <tobias at grosser.es> a écrit : > On 07/04/2013 01:39 PM, Stéphane Letz wrote: >> Hi, >> >> Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be

Hi, We are experimenting directly generating vectorized LLVM IR (using <8 x float> kind of types), then compiling the code to SSE on a 64 bits machine. Right now the equivalent code in scalar mode sill outperform the SSE one. What is the quality of the SSE support in X86 LLVL backend? Are they any specific things to be aware of to improve the speed? Thanks Stéphane Letz

> ------------------------------ > > Message: 4 > Date: Wed, 2 Jun 2010 11:07:39 -0700 > From: Dale Johannesen <dalej at apple.com> > Subject: Re: [LLVMdev] Generating Floating point constants > To: St?phane Letz <letz at free.fr> > Cc: llvmdev at cs.uiuc.edu > Message-ID: <AEC895CC-E887-4329-8743-FA606BD401F6 at apple.com> > Content-Type:

On Sat, May 29, 2010 at 1:23 AM, Stéphane Letz <letz at grame.fr> wrote: >> >> <32 x float> takes up 8 SSE registers; you're likely running into >> issues with register pressure.  Does it work better if you use >> something smaller like <4 x float>? >> >> Besides that, I don't see any obvious issues. >> >> -Eli > >

Hi, In case it is of any help, to compile a static library for the iPhone, I had to add the following 2 lines in plc.c file : #include "arch.h" #include "stack_alloc.h" otherwise "celt_word16..." type are not defined and "VARDECL...." also not. Best Regards St?phane Letz

Le 29 mai 2010 à 01:08, Bill Wendling a écrit : > Hi Stéphane, > > The SSE support is the LLVM backend is fine. What is the code that's generated? Do you have some short examples of where LLVM doesn't do as well as the equivalent scalar code? > > -bw > > On May 28, 2010, at 12:13 PM, Stéphane Letz wrote: We are actually testing LLVM for the Faust language

On Thu, Jul 18, 2013 at 9:07 AM, Stéphane Letz <letz at grame.fr> wrote: > Hi, > > Our DSL LLVM IR emitted code (optimized with -O3 kind of IR ==> IR passes) runs slower when executed with the LLVM 3.3 JIT, compared to what we had with LLVM 3.1. What could be the reason? > > I tried to play with TargetOptions without any success… > > Here is the kind of code we use to

Hi, We have a compiler for the Faust language (faust.grame.fr) that currently compiles a C++ class which implements a DSP plug-in with several methods. Our strategy to compile LLVM IR instead is the following: - use the current Faust ==> C++ compiler to compile a "empty" plug-in that we use as a template C++ class. - compile this template C++ class using "llvm-g++

Hi, We have a web page on our "LLVM backend for Faust" project available here: http://www.grame.fr/~letz/faust_llvm.html. Best Regards Stephane Letz

On Jul 5, 2013, at 10:43 AM, Stéphane Letz <letz at grame.fr> wrote > > 1) "entry" block is the first block of the function right? Yes. > > 2) do you mean *all* "alloca" in a function always have to be in the fist entry block? If you want them converted into ssa variables early on, yes.

Le 5 juil. 2013 à 17:48, Arnold Schwaighofer <aschwaighofer at apple.com> a écrit : > > On Jul 5, 2013, at 10:43 AM, Stéphane Letz <letz at grame.fr> wrote >> >> 1) "entry" block is the first block of the function right? > > Yes. OK > >> >> 2) do you mean *all* "alloca" in a function always have to be in the fist entry

Le 18 juil. 2013 à 19:07, Eli Friedman <eli.friedman at gmail.com> a écrit : > On Thu, Jul 18, 2013 at 9:07 AM, Stéphane Letz <letz at grame.fr> wrote: >> Hi, >> >> Our DSL LLVM IR emitted code (optimized with -O3 kind of IR ==> IR passes) runs slower when executed with the LLVM 3.3 JIT, compared to what we had with LLVM 3.1. What could be the reason? >>