Displaying 20 results from an estimated 976 matches for "interleaves".
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2005 Nov 15
2
OggPCM2 : chunked vs interleaved data
Michael Smith wrote:
>Whilst I accept that there are many good uses for chunked data, I
>think the transformation 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
2016 Aug 05
3
enabling interleaved access loop vectorization
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 to BasicTTI where the costing is not
2005 Nov 15
4
OggPCM2 : chunked vs interleaved data
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
2016 Aug 05
2
enabling interleaved access loop vectorization
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 hope we can enable it on x86 with a conservative
cost function, and still get
2016 May 26
2
enabling interleaved access loop vectorization
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 we estimate the number of shuffles, the shuffles are not generated in-place. Vectorizer
2006 Mar 06
3
Interleaving elements of two vectors?
Suppose one has
x <- c(1, 2, 7, 9, 14)
y <- c(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
2018 Feb 06
2
[RFC] Make LoopVectorize Aware of SLP Operations
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
2016 May 26
0
enabling interleaved access loop vectorization
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
2018 Feb 08
0
[RFC] Make LoopVectorize Aware of SLP Operations
Hi Florian!
This proposal sounds pretty exciting! Integrating SLP-aware loop vectorization (or the other way around) and SLP into the VPlan framework is definitely aligned with the long term vision and we would prefer this approach to the LoopReroll and InstCombine alternatives that you mentioned. We prefer a generic implementation that can handle complicated cases to something ad-hoc for some
2019 Sep 10
3
loop vectorizer disabling
I would like to propose 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
2019 Apr 22
1
Compress interleaved multi-channels pcm/wav with opus
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
2010 Nov 03
1
[LLVMdev] LLVM x86 Code Generator discards Instruction-level Parallelism
Dear LLVMdev,
I've noticed an unusual behavior of the LLVM x86 code generator (with default options)
that results in nearly a 4x slow-down in floating-point throughput for my microbenchmark.
I've written a compute-intensive microbenchmark to approach theoretical peak
throughput of the target processor by issuing a large number of independent
floating-point multiplies. The distance
2016 Sep 01
2
enabling interleaved access loop vectorization
So turns out it is a full reproducer after all (choosing to vectorize on AVX), good.
> The details are in PR29025.
Interesting. (So we should carefully insert unconditional branches inside shuffle sequences, eh? ;-)
> But if we modify the program by adding "*out++ = 0" right after "*out++ = q;" (thus eliminating the pesky <12 x i8>), we get:
Indeed such
2016 Nov 28
2
Loop Vectorize: Testing cost model driven transformations
Note: This is a continuation 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
2016 Aug 17
2
enabling interleaved access loop vectorization
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
2016 Aug 09
2
enabling interleaved access loop vectorization
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
2005 Nov 13
3
OggPCM format description, rev 3
> Unfortunately the ALSA API defines a number of formats which are
> in practice extremely rare. In particular, any unsigned int format
> larger than 8 bits. For instance, the only unsigned int type that
> libsndfile supports is unsigned 8 bit.
I expected this, it just seemed like a good starting point to get more
than 7 formats on the table. Specifically I wanted to the logarithmic
2005 Nov 15
0
OggPCM2 : chunked vs interleaved data
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
2002 May 27
2
Interleaved writes fwom W2K and NT4
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-February/067221.html
I sent
2005 Jun 06
1
Interleave cells with IP over ATM?
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 overhead of much smaller MTU,
which is the other way