search for: interleav

...sformation is trivial, particularly given certain >characteristics of the Ogg container. Remember, the data, if you read >an ogg stream into memory, is _already_ likely to be non-contiguous, >due to ogg's structure. It's trivial, and has insignificant additional >overhead, to de-interleave as you read it into a packet buffer. > > > Could you elaborate on this? I'm not familiar enough with the ogg API, but as far as I can tell, the way you'd do this would be to get the whole interleaved packet out with ogg_stream_packetout and then walk through it to de-interlea...

Hi Michael, Sometime back I did some experiments with interleave vectorizer and did not found any degrade, probably my tests/benchmarks are not extensive enough to cover much. Elina is the right person to comment on it as she already experienced cases where it hinders performance. For interleave vectorizer on X86 we do not have any specific costing, it goes t...

Hi all, The remaining issue to be decided for the OggPCM2 spec is the support of chunked vs interleaved data. Just so that everyone understands what we are talking about, consider a stereo file that gets stored as an OggPCM file. Within an OggPCM packet, the audio samples for the left and right channels can be stored as interleaved where the samples would be: l0, r0, l1, r1, ..... lN, rN or...

Regarding InterleavedAccessPass - sure, but proper strided/interleaved access optimization ought to have a positive impact even without target support. Case in point - Hal enabled it on PPC last September. An important difference vs. x86 seems to be that arbitrary shuffles are cheap on PPC, but, as I said below, I hop...

Interleaved access is not enabled on X86 yet. We looked at this feature and got into conclusion that interleaving (as loads + shuffles) is not always profitable on X86. We should provide the right cost which depends on number of shuffles. Number of shuffles depends on permutations (shuffle mask). And even if...

...71, 72, 77) How would one write an R function which alternates between elements of one vector and the next? In other words, one wants z <- c(x[1], y[1], x[2], y[2], x[3], y[3], x[4], y[4], x[5], y[5]) I couldn't think of a clever and general way to write this. I am aware of gdata::interleave() but it deals with interleaving rows of a data frame, not elems of vectors. -- Ajay Shah http://www.mayin.org/ajayshah ajayshah at mayin.org http://ajayshahblog.blogspot.com <*(:-? - wizard who doesn't know the answer.

Hello, We would like to propose making LoopVectorize aware of SLP operations, to improve the generated code for loops operating on struct fields or doing complex math. At the moment, LoopVectorize uses interleaving to vectorize loops that operate on values loaded/stored from consecutive addresses: vector loads/stores are generated to combine consecutive loads/stores and then shufflevector is used to de-interleave/interleave the loaded/stored values. At the moment however, we fail to detect cases where...

On 26 May 2016 at 19:12, Sanjay Patel via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Is there a compile-time and/or potential runtime cost that makes > enableInterleavedAccessVectorization() default to 'false'? > > I notice that this is set to true for ARM, AArch64, and PPC. > > In particular, I'm wondering if there's a reason it's not enabled for x86 in > relation to PR27881: > https://llvm.org/bugs/show_bug.cgi?id=27881 Hi...

...can handle complicated cases to something ad-hoc for some simple ones. Because of this, we would have some comments regarding the design that you propose: > 1. Detect loops containing SLP opportunities (operations on compound > values) > 2. Extend the cost model to choose between interleaving or using > compound values > 3. Add support for vectorizing compound operations to VPlan Currently, VPlan is not fully integrated in all the stages of the inner loop vectorizer pipeline. For that reason, part of your implementation (#1 and #2) would happen outside of VPlan and anot...

...opose that loop pragma `vectorize(disable)` actually means disabling the vectorizer for that loop. This perhaps sounds really obvious (I hope it does), but currently `vectorize(disable)` sets the vectorization width to 1, and that means the vectorizer will run and could perform other tricks such as interleaving. The main reason to change the behaviour is that it will be more what (most) users would expect. I think we reached consensus on changing the behaviour in [4], but since this is changing the behaviour of a user-facing pragma, we would like to know if there are any objections. If people rely on...

Hello everyone, I tried to compress audio with opus-1.3.1/src/opus_demo.c recently, which works fine on mono and stereo data . Now I want to compress interleaved 7 channels pcm/wav ( recorded by Microphone array :6mic+ 1reference signal ) with opus, But I have not found an interface that compress multi-channels pcm/wav. 1、Is there a multi-channel compression interface can be used in my case? If so, where is it, and how can I call it? is there a demo? If...

...the latency of the floating-point functional unit in my Intel Core2 Quad (Q9550 at 2.83 GHz). The microbenchmark itself replicates the following block 512 times: . . { p1 = p1 * a; p2 = p2 * b; p3 = p3 * c; p4 = p4 * d; } . . Compiling with NVCC, Ocelot, and LLVM, I can confirm the interleaved instruction schedule with a four-instruction reuse distance. An excerpt follows: . . %r1500 = fmul float %r1496, %r24 ; compute %1500 %r1501 = fmul float %r1497, %r23 %r1502 = fmul float %r1498, %r22 %r1503 = fmul float %r1499, %r21 %r1504 = fmul float %r1500, %r24 ; first use o...

...hovsky at intel.com>; Renato Golin <renato.golin at linaro.org>; Matthew Simpson <mssimpso at codeaurora.org>; Nema, Ashutosh <Ashutosh.Nema at amd.com>; Sanjay Patel <spatel at rotateright.com>; llvm-dev <llvm-dev at lists.llvm.org> Subject: Re: [llvm-dev] enabling interleaved access loop vectorization So, at least for this example, it looks like we actually want to vectorize with -enable-interleaved-mem-accesses, we just need the backend to generate good code for the vector types that produces, specifically, in this case, <12 x i8>. The details are in PR29025....

...ntinuation of a discussion over at https://reviews.llvm.org/D26869. Hi all, In a discussion over on llvm-commits, we are debating how best to test loop vectorization transformations that are guided by the cost model. The cost model is currently used primarily for determining the vectorization and interleave factors. Both of these parameters are easily overridden with command line flags, which enables us to create target-independent tests. Tests that rely on specific TTI hooks and instruction costs are placed under the target-specific directories. Target-independent tests are great because we don'...

Thanks Ayal! On Wed, Aug 17, 2016 at 2:14 PM, Zaks, Ayal <ayal.zaks at intel.com> wrote: > Hi Michael, > > > > Don’t quite have a full reproducer for you yet. You’re welcome to try and > see what’s happening in 32 bit mode when enabling interleaving for the > following, based on “https://en.wikipedia.org/wiki/YIQ#From_RGB_to_YIQ”: > > > > void rgb2yik (char * in, char * out, int N) > > { > > int j; > > for (j = 0; j < N; ++j) { > > unsigned char r = *in++; > > unsigned char g = *in...

Thanks Ayal! I'll take a look at DENBench. As another data point - I tried enabling this on our internal benchmarks. I'm seeing one regression, and it seems to be a regression of the "good" kind - without interleaving we don't vectorize the innermost loop, and with interleaving we do. The vectorized loop is actually significantly faster when benchmarked in isolation, but in this specific instance, the static loop count is unknown, and the dynamic loop count happens to almost always be 1 - and this lives i...

...in all this is a huge PITA. In comparison > to FLAC, Speex and Vorbis, APDCM formats have little to offer. No objection here. I'd like to see someone other than myself go through and cull the list of formats into whatever a practical subset is. As long as it does 16 bit signed little endian interleaved, I'll be happy. > I still think that assigning meaning to bits within the format field > is a mistake. Specifying bits like this could only be useful if > you expect the decoder to generate code on the fly when it gets > asked to decode say 16 bit, unsigned, little endian. Auto g...

On 11/15/05, Erik de Castro Lopo <mle+xiph@mega-nerd.com> wrote: > Hi all, > > The remaining issue to be decided for the OggPCM2 spec is the support > of chunked vs interleaved data. I think interleaved is the obvious choice - that's what most audio applications are used to dealing with, it's what we need to feed to audio hardware in the end usually, etc. Whilst I accept that there are many good uses for chunked data, I think the transformation is trivial, par...

Hi Jerry I'm still able to recreate failures in with 2.2.4 when interleaving file creation/writing from W2k and NT4 machines to a Samba server. I orginally reported this in 2.2.2a, also 2.2.3: http://lists.samba.org/pipermail/samba/2001-December/063396.html http://lists.samba.org/pipermail/samba/2002-January/063483.html http://lists.samba.org/pipermail/samba/2002-Februa...

Anyone know if it''s possible to interleave two IP packets when using PPPoA and VC based lines? Can it be done with any PPPoE implementations? The goal is to reduce the delay when you have a high priority packet waiting, but a lower priority (large) packet already started going out ahead of this packet. I don''t want the overh...