Displaying 20 results from an estimated 2000 matches similar to: "[LLVMdev] Instrumentation based Profiling"
2014 Jun 25
2
[LLVMdev] Getting LNT to work with non-bash shell
The attached patch didn't fix it, but when I also changed another == to = a
few lines further down it seemed to work.
Jeremy
On Tue, Jun 24, 2014 at 10:07 PM, Justin Bogner <mail at justinbogner.com>
wrote:
> Jeremy Salwen <jeremysalwen at gmail.com> writes:
> > I followed the LNT quickstart guide
> > (http://llvm.org/docs/lnt/quickstart.html) on my debian
2014 Jun 12
3
[LLVMdev] Creating and implementing an analysis group out of tree
Hi Eli,
Thanks for the link! I'm able to compile a standalone pass outside of the
source tree, and I'm obviously ably to compile analysis groups inside the
source tree. However, the problem comes when I try to do what the tutorial
suggests to create an analysis group outside of the source tree.
My understanding is that building out of tree requires different methods to
register the
2014 Aug 04
3
[LLVMdev] Matching up inlined basic blocks with original basic blocks.
Hello All,
I have some data tied to the basic blocks in a function, and after inlining
that function, I'd like to recover that data in the inlined version. Is
there some way to match up the inlined version of the function with the
original basic blocks?
Thanks,
Jeremy
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2014 Aug 21
2
[LLVMdev] Alias Analysis Semantics
Hi Hal,
Thank you for your email, that makes a lot of sense to me. I am working on
some tools to use memory profiling to speculatively replace memory loads
and stores with value forwarding in hardware implementations. I'd like to
compare the profiled data to static alias analysis, so it would be super
useful if there was a way to answer the questions about aliasing across
backedges that
2014 Aug 13
2
[LLVMdev] Alias Analysis Semantics
Thanks Daniel!
I think you've cleared up some of my misconceptions, but I still am a bit
confused about some of the corner cases.
Suppose we had something like this
std::vector<int> A(100);
> int* x,y;
> x=&A[0];
>
for(int i=0; i<100; i++) {
> y=&A[i];
> *y=*x;
> x=&A[i+1];
> }
>
Would the load and store instructions be MustAlias? I
2015 Jul 17
2
[LLVMdev] LLVM instrumentation
The PGO was my first guess but I can get a lot of information.
At first, I follow the explanation at http://clang.llvm.org/docs/UsersManual.html#profiling-with-instrumentation but instead of llvm-profdata merge, I used llvm-profdata show *.profraw.
Sadly, the information I get is the total number of function, the maximum function count and the maximum internal block count.
Do you know if you
2014 Aug 14
2
[LLVMdev] Alias Analysis Semantics
Hey Daniel,
Thanks again for the help. I'm still a bit confused about the interface to
the alias analysis. It seems like we are talking about different
interfaces. Has it changed from what the documentation says? As far as I
can tell, the documentation takes a specific Value*, and no information
about which dynamic execution it is talking about.
When you say "Right. It's a
2015 Jul 17
3
[LLVMdev] LLVM instrumentation
Yeah I have already see pintool but I need this to work with ARM and Intel.
If I remember correctly, pintool does not work on ARM (or quite bad).
My goal with the instrumentation is, once I have the information (time + call), to choose (during a second compilation) if some of my passes are applicable or not.
Greetings,
Johan
On 17 Jul 2015, at 16:09, Kenneth Adam Miller <kennethadammiller
2014 Aug 21
2
[LLVMdev] Alias Analysis Semantics
Hi Daniel,
Sorry for taking so long to respond. I spoke with a colleague more
familiar with llvm who thought he could clear up my confusion, but we both
came out of the conversation confused. I will try my best to explain the
ambiguity.
In an DAG, alias queries would be completely unambiguous. Every
instruction would only be executed once, and every SSA value really would
have a single static
2014 Jun 12
2
[LLVMdev] Creating and implementing an analysis group out of tree
Hello all,
I'm trying to follow the guide http://llvm.org/docs/WritingAnLLVMPass.html
to build an some passes and analysis groups out of tree. However, I'm
having some trouble with crashes when I try to follow the guide.
The first section provides a very useful example of what the whole .cpp
file should look like for the HelloWorld pass. Obviously it's a bit more
complex to write the
2014 Aug 14
2
[LLVMdev] Alias Analysis Semantics
On Thu, Aug 14, 2014 at 6:37 AM, Daniel Berlin <dberlin at dberlin.org> wrote:
> On Wed, Aug 13, 2014 at 8:35 PM, Jeremy Salwen <jeremysalwen at gmail.com> wrote:
>> Hey Daniel,
>>
>> Thanks again for the help. I'm still a bit confused about the interface to
>> the alias analysis. It seems like we are talking about different
>> interfaces.
>
2015 May 22
0
[LLVMdev] RFC - Improvements to PGO profile support
On Fri, May 22, 2015 at 11:16 AM, Dario Domizioli
<dario.domizioli at gmail.com> wrote:
> Hi all,
>
> I am a bit confused about the documentation of the format of the profile
> data file.
>
> The Clang user guide here describes it as an ASCII text file:
> http://clang.llvm.org/docs/UsersManual.html#sample-profile-format
>
> Whereas the posts above and the
2015 May 28
3
[LLVMdev] RFC - Improvements to PGO profile support
Hi Diego,
thanks for clarifying the difference between the two formats. I have
noticed the new note in the "Sample Profile Format" section of the Clang
guide clarifying that it is different from the coverage format.
So, my further question is... Am I right in understanding that both formats
can be used for PGO purposes then?
I have tried the following, as in the Clang user guide:
$
2014 Jun 24
2
[LLVMdev] Getting LNT to work with non-bash shell
I followed the LNT quickstart guide (
http://llvm.org/docs/lnt/quickstart.html) on my debian machine, and it
seems to have a problem running. When I consult test.log, every single
test has a section like this
# Pretend that the reference output was produced instantaneously.
> cp /home/jeremy/hardware/llvm/test-suite/instant.txt
> Output/sse.expandfft.out-nat.time
>
2014 Aug 13
2
[LLVMdev] Alias Analysis Semantics
Hello all,
I've read the documentation on alias analysis, and I think I understand it
literally, but I just want to be sure, because it seems a bit strange.
As it says on this web page <http://llvm.org/docs/AliasAnalysis.html>,
The MayAlias response is used whenever the two pointers might refer to the
> same object.
>
> The PartialAlias response is used when the two memory
2015 May 22
2
[LLVMdev] RFC - Improvements to PGO profile support
Hi all,
I am a bit confused about the documentation of the format of the profile
data file.
The Clang user guide here describes it as an ASCII text file:
http://clang.llvm.org/docs/UsersManual.html#sample-profile-format
Whereas the posts above and the referenced link describe it as a stream of
bytes containing LEB128s:
http://www.llvm.org/docs/CoverageMappingFormat.html
>From experimenting
2016 Feb 05
2
Profiling with LLVM.
Dear Duncan,
I am generating branch-weights annotated IR files as described in the
documentation of LLVM, using profiling with instrumentation.
http://clang.llvm.org/docs/UsersManual.html#profiling-with-instrumentation
e.g.
llvm-profdata merge -output=$(BENCH).profdata default.profraw
> clang -S -emit-llvm -O3 -fprofile-instr-use=$(BENCH).profdata -o
> bench.prof.ll bench.c
The issue is
2015 May 27
4
[LLVMdev] Capabilities of Clang's PGO (e.g. improving code density)
Hello -
I'm an Engineer in Microsoft Office after looking into possible advantages of using PGO for our Android Applications.
We at Microsoft have deep experience with Visual C++'s Profile Guided Optimization<https://msdn.microsoft.com/en-us/library/e7k32f4k.aspx> and often see 10% or more reduction in the size of application code loaded after using PGO for key scenarios (e.g.
2015 Aug 13
17
[3.7 Release] Let's fix the release notes!
Dear everyone,
The in-progress release notes for 3.7 [1,2] make it look like we
didn't do very much over the past six months. Obviously that's not the
case at all, so let's get them in shape!
If you've been thinking "I should probably add this to the release
notes at some point", now is the time :-)
I have a list below of changes that might be worth mentioning. I
2016 Feb 04
2
Profiling with LLVM.
Dear Duncan,
Thank you a lot for your feedback. I have a problem though. The branch
weights counters overflow in some files and thus I get incorrect numbers.
Is there any way to find a workaround for that? Is is supposed to be a
known bug or is it something that needs configuration on my part?
Again, thank you a lot for your reply.
Best Regards,
Georgios Zacharopoulos
2016-02-03 18:23