Displaying 20 results from an estimated 933 matches for "discriminate".
2016 Oct 27
8
(RFC) Encoding code duplication factor in discriminator
Motivation:
Many optimizations duplicate code. E.g. loop unroller duplicates the loop
body, GVN duplicates computation, etc. The duplicated code will share the
same debug info with the original code. For SamplePGO, the debug info is
used to present the profile. Code duplication will affect profile accuracy.
Taking loop unrolling for example:
#1 foo();
#2 for (i = 0; i < N; i++) {
#3 bar();
2020 Nov 17
3
[RFC] Control Flow Sensitive AutoFDO (FS-AFDO)
Hi all,
Here I include an RFC for control flow sensitive AutoFDO (FS-AFDO). This is
a joint work with David Li. Questions and feedback are welcome.
Thanks,
Rong
=============
[RFC] Control Flow Sensitive AutoFDO (FS-AFDO)
1. Motivation
AFDO profile is derived from PMU samples from running an earlier build
binary. PMU samples are indexed by the IP addresses. An offline tool uses
the debug
2016 Oct 27
2
(RFC) Encoding code duplication factor in discriminator
The impact to debug_line is actually not small. I only implemented the part
1 (encoding duplication factor) for loop unrolling and loop vectorization.
The debug_line size overhead for "-O2 -g1" binary of speccpu C/C++
benchmarks:
433.milc 23.59%
444.namd 6.25%
447.dealII 8.43%
450.soplex 2.41%
453.povray 5.40%
470.lbm 0.00%
482.sphinx3 7.10%
400.perlbench 2.77%
401.bzip2 9.62%
403.gcc
2016 Oct 27
0
(RFC) Encoding code duplication factor in discriminator
Do you have an estimate of the debug_line size increase? I guess it will be
small.
David
On Thu, Oct 27, 2016 at 11:39 AM, Dehao Chen <dehao at google.com> wrote:
> Motivation:
> Many optimizations duplicate code. E.g. loop unroller duplicates the loop
> body, GVN duplicates computation, etc. The duplicated code will share the
> same debug info with the original code. For
2016 Oct 27
0
(RFC) Encoding code duplication factor in discriminator
Is there prior art for this sort of thing (in GCC, for example) - I take it
this isn't the first time this has come up as a problem for profile
accuracy? (so it'd be helpful to know prior solutions to this (& if we're
not doing whatever was done before, what it is about our situation that's
different, etc), or why it hasn't been a problem, etc)
On Thu, Oct 27, 2016 at
2010 Dec 14
4
Discriminant Correspondence Analysis
Hello everyone,
I am totally new to the R program. I have had a look at some pdf documents
that I downloaded and that explain how to do many things in R; however, I
still cannot figure out how to do what I want to do, which is to perform
Discriminant Correspondence Analysis on a rectangular matrix of data that I
have in an Excel file. I know R users frown upon Excel and recommend
converting Excel
2016 Oct 27
0
(RFC) Encoding code duplication factor in discriminator
The large percentages are from those tiny benchmarks. If you look at
omnetpp (0.52%), and xalanc (1.46%), the increase is small. To get a better
average increase, you can sum up total debug_line size before and after and
compute percentage accordingly.
David
On Thu, Oct 27, 2016 at 1:11 PM, Dehao Chen <dehao at google.com> wrote:
> The impact to debug_line is actually not small. I only
2016 Oct 28
1
(RFC) Encoding code duplication factor in discriminator
Hi Dehao,
This is definitely an important problem, thanks for writing this up!
There is a related problem that I think we can address at the same time: When we multiversion code, for example when we use runtime checks to enable the creation of a vectorized loop while retaining the scalar loop, and then we collect profiling data, we should be able to recover the relative running time of the
2020 Nov 19
0
[RFC] Control Flow Sensitive AutoFDO (FS-AFDO)
Hi Rong,
This is a very interesting proposal. We've also observed profile quality degradation from CFG destructive pass like loop rotate, and I can see how this proposal would help improve quality of profile that drives later optimization passes in the pipeline. I have a few questions.
* How does this affect today's AutoFDO? Specifically, can users upgrade compiler with FS-AutoFDO
2016 Oct 27
1
(RFC) Encoding code duplication factor in discriminator
It looks like the example doesn't use the encoding described in the text?
Assume that the discriminator is uint32. The traditional discriminator is less than 256, let's take 8 bit for it. For duplication factor (type 1 duplication), we assume the maximum unroll_factor * vectorize_factor is less than 256, thus 8 bit for it. For unique number(type 2 duplication), we assume code is at most
2016 Nov 01
2
(RFC) Encoding code duplication factor in discriminator
----- Original Message -----
> From: "Dehao Chen" <dehao at google.com>
> To: "Hal Finkel" <hfinkel at anl.gov>
> Cc: "Xinliang David Li" <davidxl at google.com>, "llvm-dev"
> <llvm-dev at lists.llvm.org>
> Sent: Tuesday, November 1, 2016 11:43:41 AM
> Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor
2016 Nov 02
2
(RFC) Encoding code duplication factor in discriminator
----- Original Message -----
> From: "Dehao Chen" <dehao at google.com>
> To: "Hal Finkel" <hfinkel at anl.gov>
> Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Xinliang David Li"
> <davidxl at google.com>
> Sent: Tuesday, November 1, 2016 8:24:30 PM
> Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in
2005 Jul 05
4
Discriminant Function Analysis
...This is more of a statistics question than a question about help for R,
so forgive me.
I am using lda from the MASS package to perform linear discriminant
function analysis. I have 14 cases belonging to two groups and have
measured each of 37 variables. I want to find those variables that best
discriminate between the two groups, and I want to visualise that and
create a classification function. Please note at this stage it is a
proof of concept problem - I realise that I must follow this up with a
much more robust anaylsis involving cross-validation.
1) First problem, I got this error message:
>...
2016 Nov 04
2
(RFC) Encoding code duplication factor in discriminator
Discussed with Hal, Adrain and Paul offline at the llvm dev meeting today.
* trip count is not enough for vectorization, there is runtime check that
might go false, which can be reflected in profile that we may want to
preserve.
* simply recording these context-profile may cause problems to
iterative-sample-pgo. i.e. when you find a loop's vectorized version no
executed (due to runtime
2016 Nov 21
4
(RFC) Encoding code duplication factor in discriminator
In many cases, the line-table fussing to improve autoFDO/sample-PGO would also likely help the debugging experience for optimized code, certainly in cases where line attribution is inherently ambiguous. In those cases, I have no problem with Just Doing It.
Something likely to pad the line table to benefit profiling without similarly benefiting debugging… that's probably worth inventing a
2016 Nov 01
2
(RFC) Encoding code duplication factor in discriminator
----- Original Message -----
> From: "Dehao Chen" <dehao at google.com>
> To: "Hal Finkel" <hfinkel at anl.gov>
> Cc: "Xinliang David Li" <davidxl at google.com>, "llvm-dev"
> <llvm-dev at lists.llvm.org>
> Sent: Tuesday, November 1, 2016 1:24:01 PM
> Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in
2005 Sep 29
1
Fisher's discriminant functions
Hi everyone,
I'm trying to solve a problem about how to get the
Fisher's discriminant functions of a "lda" (linear
discriminant analysis) object, I mean, the object
obtained from doing "lda(formula, data)" function of
the package MASS in R-project. This object gives me
the canonical linear functions (n-1 coefficients
matrix of n groups at least), and only with this
2016 Nov 01
2
(RFC) Encoding code duplication factor in discriminator
As illustrated in the above example, it is not like "vectorization has a distinct bit". All different optimizations make clones of code which will be labeled by UIDs represented by N (e.g. 8) bits. In this way, the space will be capped by the number of clones all optimizations have made, instead of # of optimizations that has applied. And it will be capped at 2^N-1. The cons of using uid
2016 Nov 02
3
(RFC) Encoding code duplication factor in discriminator
----- Original Message -----
> From: "Dehao Chen" <dehao at google.com>
> To: "Hal Finkel" <hfinkel at anl.gov>
> Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Xinliang David Li"
> <davidxl at google.com>
> Sent: Tuesday, November 1, 2016 6:41:29 PM
> Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in
2009 Jan 02
2
[LLVMdev] Suggestion: Support union types in IR
On Jan 1, 2009, at 6:25 AM, Jon Harrop wrote:
>> Exactly. I'm not especially interested in C-style unions, I'm
>> interested
>> in discriminated unions. But the actual discriminator field is easily
>> represented in LLVM IR already, so there's no need to extend the IR
>> to
>> support them. That's why I am only asking for C-style union support -
>> it's a lower-level primitive that you can use to build...