search for: scops

Hi all, I have investigated the compile-time overhead of "Polly Scop Detection" pass based on LNT testing results. This mail is to share some results I have found. (1) Analysis of "SCOP Detection Pass" for PolyBench (Attached file PolyBench_SCoPs.log) Experimental results show that the "SCOP Detection pass" does not lead to significant extra compile-time overhead for compiling PolyBench. The percent of compile-time overhead caused by "SCOP Detection Pass" is usually less than 4% of total compile-time. Details for each be...

...i all, > > > > I have investigated the compile-time overhead of "Polly Scop Detection" pass based on LNT testing results. > This mail is to share some results I have found. > > > (1) Analysis of "SCOP Detection Pass" for PolyBench (Attached file PolyBench_SCoPs.log) > Experimental results show that the "SCOP Detection pass" does not lead to significant extra compile-time overhead for compiling PolyBench. The percent of compile-time overhead caused by "SCOP Detection Pass" is usually less than 4% of total compile-time. Details for ea...

...; >> I have investigated the compile-time overhead of "Polly Scop Detection" pass based on LNT testing results. >> This mail is to share some results I have found. >> >> >> (1) Analysis of "SCOP Detection Pass" for PolyBench (Attached file PolyBench_SCoPs.log) >> Experimental results show that the "SCOP Detection pass" does not lead to significant extra compile-time overhead for compiling PolyBench. The percent of compile-time overhead caused by "SCOP Detection Pass" is usually less than 4% of total compile-time. Details fo...

...- Number of bad regions for Scop: Non canonical induction variable in loop 8 polly-detect - Number of bad regions for Scop: Others 53 polly-detect - Number of regions that a valid part of Scop This seems to suggest that we most scops fail due to loop bounds that can not be computed. It would be interesting to see what kind of expressions these are. In case SCEV often does not deliver a result, this may be one of the cases where bottom up scop detection would help a lot, as outer regions are automatically invalidated if we can...

>Great. Now we have two test cases we can work with. Can you >upload the LLVM-IR produced by clang -O0 (without Polly)? Since tramp3d-v4.ll is to large (19M with 267 thousand lines), I would focus on the oggenc benchmark at firat. I attached the oggenc.ll (LLVM-IR produced by clang -O0 without Polly), which compressed into the file oggenc.tgz. >2) Check why the Polly scop detection is

>> (3) About detecting scop regions in bottom-up order. >> Detecting scop regions in bottom-up order can significantly speed up the scop detection pass. However, as I have discussed with Sebastian, detecting scops in bottom-up order and up-bottom order will lead to different results. As a result, we should not change the detection order. > >Sebastian had a patch for this. Does his patch improve the scop >detection time. LNT testing results for Sebastian's patch file can be seen on http://188.4...

...y=0; B = (char *)malloc(sizeof(char)*1024*1024); for (i = 1; i < 1024; i++) for (j = 1; j < 1024; j++) { if (i+j > 1000) B[j] = i; } printf("Random Value: %d", B[rand() % 1024*1024]); return 0; } running: opt -load ${PATH_TO_POLLY_LIB}/LLVMPolly.dylib -polly-scops -analyze code.preopt.ll I get: Printing analysis 'Polly - Create polyhedral description of Scops' for region: 'for.body3 => for.inc.single_exit' in function 'main': Invalid Scop! 0 libLLVM-3.1svn.dylib 0x0000000103fab905 _ZL15PrintStackTracePv + 53 1 libLLVM-3.1svn.dy...

Perfect, thank you very much :) 2011/10/26 Tobias Grosser <tobias at grosser.es>: > On 10/24/2011 11:32 PM, Marcello Maggioni wrote: >> >> Strange , with --enable-shared (I use auto tool by the way ...) it gives: >> >> MacBook-Pro-di-Marcello:examples Kariddi$ ./compile_ex.sh >> not_so_simple_loop >> clang (LLVM option parsing): Unknown command line

Dear Community, I would like to summarize my work till date for GSoC 2016. Till the current phase of my project, I have mostly focused on developing the necessary infrastructure to use analysis results from Polly in LLVM. Initial plan as mentioned in the proposal: For the first month:- 1. Decouple ScopInfo pass from Polly’s pass chain and provide capability to create SCoP(Static

Hi, I'm using Polly to analyze memory access patterns for an university project and I'm trying to get polly working on some loops that polly marks as "containing non affine branches" . >From what I understand polly skips Scops that contain these branches (which comprises something like "if (i % 2 == 0)" where i is a loop varying variable) because these kind of branches can make , in practice , non affine the accesses to the memory operands even if the array subscript expression is affine itself, but I need a mu...

...as I know, both llvm-gcc and Polly already offer support for OpenMP, by inserting calls to the gomp library. Can this code be reused? Is there a pass that I can call to do all these code transformations? I had a look at the CodeGeneration from Polly. Is it possible to use it without creating the Scops, by transforming it into a LoopPass? Could you indicate how is this handled in llvm-gcc? Thank you for your help. Alexandra. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110908/a29ab04f/attachment.html&g...

...       { >                        if (i+j > 1000) >                                B[j] = i; > } >        printf("Random Value: %d", B[rand() % 1024*1024]); > >        return 0; > } > > running: > > opt -load ${PATH_TO_POLLY_LIB}/LLVMPolly.dylib -polly-scops -analyze > code.preopt.ll > > I get: > > Printing analysis 'Polly - Create polyhedral description of Scops' for > region: 'for.body3 => for.inc.single_exit' in function 'main': > Invalid Scop! > 0  libLLVM-3.1svn.dylib 0x0000000103fab905 _ZL15Print...

...gt; Hi, I'm using Polly to analyze memory access patterns for an > university project and I'm trying to get polly working on some loops > that polly marks as "containing non affine branches" . Hi Marcello, sorry for the long delay. > From what I understand polly skips Scops that contain these branches > (which comprises something like "if (i % 2 == 0)" where i is a loop > varying variable) because these kind of branches can make , in > practice , non affine the accesses to the memory operands even if the > array subscript expression is affine its...

On Fri, Oct 13, 2017 at 5:13 PM, Michael Kruse via llvm-dev < llvm-dev at lists.llvm.org> wrote: > 2017-10-14 1:29 GMT+02:00 Saito, Hideki via llvm-dev < > llvm-dev at lists.llvm.org>: > > I'm also sorry that I'm not commenting on the main part of your RFC in > this reply. I just want to focus on > > one thing here. > > > >

..., but I'm not sure :( Hi Marcello, sorry for taking so long to reply. I just had a look at your test case and found the problem. What happens is that Polly fails to accept the outer loop (an unrelated issue), such that only the inner loop is detected as a scop (you can verify this with -view-scops). Now when building the polyhedral representation we analyze the SCEV expressions in the inner loop (the scop). Here the condition has an expression that looks similar to this: {1, +, 1024}<i> + {1,+,1024}<j> We translate this expression. When reaching {1, +, 1024}<i> we do not...

...orks pretty well in many situations, but in this particular case it does not help. Those problematic "Fortran scalar values referred by pointers" (FSVRPs) can only substituted (replaced by actual value) after proper memory analysis. According to current design, memory analysis operates on SCoPs, but Polly is already unable to detect SCoP for the whole group of nested loops due to presence of those FSVRPs. So, chicken and egg problem. - D. 2013/1/2 Tobias Grosser <tobias at grosser.es> > On 01/01/2013 02:45 PM, Duncan Sands wrote: > >> Hi Dmitry, >> >> >...

2011/4/8 ether zhhb <etherzhhb at gmail.com>: > Hi, > > 2011/4/8 Vlad Krylov <krvladislav at gmail.com>: >> Hi. >> >> I see that to detect scops firstly we search for regions in CFG ( by >> RegionInfo ) and then select regions that answer some requirements ( >> in ScopDetection ). Because only affine expressions in conditions and >> bounds are permissible, we trying to get scalar expressions into >> affine form by Af...

...an invalid scop and skips all following transformations and optimizations. However, I evaluated it here to see its potential performance impact. Based on the results shown on http://188.40.87.11:8000/db_default/v4/nts/21?compare_to=16&baseline=16&aggregation_fn=median, we can see detecting scops bottom-up may further reduce Polly compile-time by more than 10%. Best wishes, Star Tan -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20130731/f8814648/attachment.html>

At 2013-08-17 23:22:32,"Tobias Grosser" <tobias at grosser.es> wrote: >On 08/17/2013 12:08 AM, Star Tan wrote: >> At 2013-08-16 22:32:30,"Tobias Grosser" <tobias at grosser.es> wrote: >>>> >>>> Yes, I have changed the original code to the form you suggested: >>>> for (i >>>> for (j >>>>

On 04/08/2011 08:35 PM, Vlad Krylov wrote: > 2011/4/8 ether zhhb<etherzhhb at gmail.com>: >> Hi, >> >> 2011/4/8 Vlad Krylov<krvladislav at gmail.com>: >>> Hi. >>> >>> I see that to detect scops firstly we search for regions in CFG ( by >>> RegionInfo ) and then select regions that answer some requirements ( >>> in ScopDetection ). Because only affine expressions in conditions and >>> bounds are permissible, we trying to get scalar expressions into >>> a...