Displaying 20 results from an estimated 4000 matches similar to: "Help regarding a project"
2010 Jun 26
2
packet loss concealment algorithm in speex speech codec
Hi,
I am an engineering student in IIT Guwahati, India. Currently, as a
summer project I am working on 'packet loss concealment in voip scenario'. I
am eager to know what PLC methods are used at receiver end of speex decoder.
And if I could develop some more efficient method I could able to contribute
to the speex. Actually, I searched the whole speex manual but failed to find
what
2020 Jun 09
2
LoopStrengthReduction generates false code
Hi.
In my backend I get false code after using StrengthLoopReduction. In the generated code the loop index variable is multiplied by 8 (correct, everything is 64 bit aligned) to get an address offset, and the index variable is incremented by 1*8, which is not correct. It should be incremented by 1 only. The factor 8 appears again.
I compared the debug output
2020 Jun 09
2
LoopStrengthReduction generates false code
Hm, no. I expect byte addresses - everywhere. The compiler should not know that the arch needs word addresses. During lowering LOAD and STORE get explicit conversion operations for the memory address. Even if my arch was byte addressed the code would be false/illegal.
Boris
> Am 09.06.2020 um 19:36 schrieb Eli Friedman <efriedma at quicinc.com>:
>
> Blindly guessing here,
2020 Jun 10
2
LoopStrengthReduction generates false code
The IR after LSR is:
*** IR Dump After Loop Strength Reduction ***
; Preheader:
entry:
tail call void @fill_array(i32* getelementptr inbounds ([10 x i32], [10 x i32]* @buffer, i32 0, i32 0)) #2
br label %while.body
; Loop:
while.body: ; preds = %while.body, %entry
%lsr.iv = phi i32 [ %lsr.iv.next, %while.body ], [ 0, %entry ]
%uglygep = getelementptr
2016 May 07
3
[GSoC 2016] Introduction - Polly as an Analysis pass in LLVM
Dear All,
I am glad to be part of GSoC 2016 with LLVM organization. I am a first year
PhD student at IIT Hyderabad, India and my research area is compiler
optimizations using polyhedral model.
My GSoC 2016 project is to implement Polly as an Analysis pass in LLVM [1].
We have a discussion on Polly-dev mailing list [2] on taking a better
approach to implement this project. Based upon this
2014 Dec 11
2
[LLVMdev] Vectorization factor limitation in Loop Vectorizer
Hi Nadav/Devs
I am exploring Loop Vectorizer to vectorize i8 scalar operations into 8xi8 vector operation.
I was expecting the Loop Vectorizer to analyze the profitability for vectorization factor(VF) of 8,
However it is not doing so due to the widest type calculation done for the blocks inside the loop.
May be I am missing something, however, I am curious to know why Loop Vectorizer limits the
2013 May 09
2
[LLVMdev] Simple Loop Vectorize Question
Hi! I am trying to get the loop vectorizer to work on a simple example
(http://pastebin.com/tGhpc4y0) that doubles every element in a vector.
I've found that 'opt -loop-vectorize -force-vector-width=4 -S -debug
double.ll' works as expected. However, removing the -force-vector-width flag
results in no vectorization. From the debug output I can see that the issue
boils down to:
LV: The
2014 Dec 13
2
[LLVMdev] Vectorization factor limitation in Loop Vectorizer
So IMO, if we modify the VF calculation for targets/subtargets using TTI where higher VF is supported
The vectorizer’s scope will become wider.
Did/do you foresee any issue with this?
Thanks,
Shahid
From: Nadav Rotem [mailto:nrotem at apple.com]
Sent: Saturday, December 13, 2014 2:47 AM
To: Shahid, Asghar-ahmad
Cc: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] Vectorization factor limitation in
2013 May 10
2
[LLVMdev] Simple Loop Vectorize Question
Nadav,
Please forgive my ignorance, but 'opt -mcpu=corei7 -loop-vectorize -S
-debug double.ll' doesn't appear to make a difference. In fact it seems to
be ignored as garbage values for -mcpu don't raise an error. Am I
overlooking something else also?
Many Thanks,
Josh
On Thu, May 9, 2013 at 6:06 PM, Nadav Rotem <nrotem at apple.com> wrote:
> Hi Josh,
>
> Your
2013 Oct 26
3
[LLVMdev] Why is the loop vectorizer not working on my function?
----- Original Message -----
> >>> LV: The Widest type: 32 bits.
> >>> LV: The Widest register is: 32 bits.
>
> Yep, we don’t pick up the right TTI.
>
> Try -march=x86-64 (or leave it out) you already have this info in the
> triple.
>
> Then it should work (does for me with your example below).
That may depend on what CPU is picks by default; Frank,
2013 May 09
0
[LLVMdev] Simple Loop Vectorize Question
Hi Josh,
Your modules does not have a triple, so the target machine and TargetTransformInfo have no way of knowing if you are running on a machine with vector registers. Try adding the '-mcpu=XXXX' to opt and see what happens.
Thanks,
Nadav
On May 9, 2013, at 1:42 PM, Josh Klontz <josh.klontz at gmail.com> wrote:
> Hi! I am trying to get the loop vectorizer to work on a
2016 Feb 19
2
target triple in 3.8
I have some trouble making the SIMD vector length visible to the passes.
My application is basically on the level of 'opt'.
What I did in version 3.6 was
functionPassManager->add(new
llvm::TargetLibraryInfo(llvm::Triple(Mod->getTargetTriple())));
functionPassManager->add(new llvm::DataLayoutPass());
and then the -basicaa and -loop-vectorizer were able to vectorize the
input
2007 Apr 11
3
Fortran coding standards
I have some comments on the Fortran code in the
fseries package in file 4A-GarchModelling.f ,
especially the subroutine GARCHFIT and function
DSNORM.
I appended the code to the end of an earlier message,
but it was rejected by some rule. Let me first say
that I am grateful that packages for financial
econometrics exist in R.
Fortran 77 had PARAMETERs, and PARAMETERs equal to
99999 and 200 should
2013 Oct 27
3
[LLVMdev] Why is the loop vectorizer not working on my function?
Hi Frank,
On Oct 26, 2013, at 6:29 PM, Frank Winter <fwinter at jlab.org> wrote:
> I would need this to work when calling the vectorizer through
> the function pass manager. Unfortunately I am having the same
> problem there:
I am not sure which function pass manager you are referring here. I assume you create your own (you are not using opt but configure your own pass
2016 Jun 15
8
[RFC] Allow loop vectorizer to choose vector widths that generate illegal types
Hello,
Currently the loop vectorizer will, by default, not consider vectorization
factors that would make it generate types that do not fit into the target
platform's vector registers. That is, if the widest scalar type in the
scalar loop is i64, and the platform's largest vector register is 256-bit
wide, we will not consider a VF above 4.
We have a command line option (-mllvm
2017 Mar 04
7
Why ISel Shifts operations can only be expanded for Value type vector ?
On Saturday, March 4, 2017, Ryan Taylor <ryta1203 at gmail.com> wrote:
> Why you can't still expand it through MUL with a Custom lowering? Or am I
> missing something?
>
> Yes we can but problem occurs when we know that it is shift with constant
value than if we return ISD::MUL with constant imm operand than LLVM will
convert it to SHL again because the constant will be
2013 Oct 26
0
[LLVMdev] Why is the loop vectorizer not working on my function?
I would need this to work when calling the vectorizer through
the function pass manager. Unfortunately I am having the same
problem there:
LV: The Widest type: 32 bits.
LV: The Widest register is: 32 bits.
It's not picking the target information, although I tried with and
without the target triple in the module.
Any idea what could be wrong?
Frank
On 26/10/13 15:54, Hal Finkel wrote:
2013 May 10
0
[LLVMdev] Simple Loop Vectorize Question
Hi Josh,
This line works for me:
opt file.ll -loop-vectorize -S -o - -mtriple=x86_64 -mcpu=corei7-avx -debug
You need to specify the triple on the command line if it is not inside the module.
Thanks,
Nadav
On May 9, 2013, at 5:53 PM, Joshua Klontz <josh.klontz at gmail.com> wrote:
> Nadav,
>
> Please forgive my ignorance, but 'opt -mcpu=corei7 -loop-vectorize -S
2013 Oct 08
1
R function for Bisecting K-means algorithm
Hi All,
Can someone please tell me* R function for Bisecting K-means algorithm*. I
have used *kmeans() *function but not getting good results.
Please help.
--
Thanks and Regards,
Vivek Kumar Singh
Research Assistant,
School of Computing,
National University of Singapore
Mobile:(0065) 82721535
[[alternative HTML version deleted]]
2005 Apr 12
8
removing characters from a string
Is there a simple way in R to remove all characters
from a string other than those in a specified set? For
example, I want to keep only the digits 0-9 in a
string.
In general, I have found the string handling abilities
of R a bit limited. (Of course it's great for stats in
general). Is there a good reference on this? Or should
R programmers dump their output to a text file and use
something