search for: isparallel

...ction pass to be used by PolyhedralInfo pass as mentioned below. 2: Decouple DependenceInfo object from pass and create two passes. Same as above. 3: Create the interface PolyhedralInfo, which will extract Memory Access wise dependence information from Polly and provide few simple interfaces like isParallel(), isVectorizable(), tripCount(Loop&). Please feel free to post your comments and suggestions on this. [1] https://docs.google.com/document/d/1QyUzL3OOwJSI91lDqr7VsvqUsFyTY9FlpAwbGSipUtw/edit# [2] https://groups.google.com/forum/#!topic/polly-dev/DuRxNmKfEnM Regards, Utpal Bora Ph.D. Schol...

...in such metadata. I agree. Thus, let's start with the 'parallel' semantics first, not the vague ones. A conclusion of some kind for me to update the patch: 1) Rename the loop branch metadata back to llvm.loop.parallel. I'll add a definition of its semantics (as comments to Loop::isParallel()): No loop-carried dependency checking at all can be assumed with this type of loops. If the compiler does some analysis to improve the performance or other reasons, it still can, but is not required to do so. 2) Keep the memory accessing instruction metadata as it is. At least until something...

Hi, In a personal capacity I'm quite interested in the issues of producing from a high-level language some LLVM IR which is labelled with vectorization info (including potentially actually reordering data in memory). | I don't have any objections. I think the only requirement is that the semantics are clearly defined. I think that's very important :-) | Personally I think this

On 01/28/2013 06:45 PM, Nadav Rotem wrote: > I am okay with this patch, assuming that you follow the review of Tobias > and Renato and provide a separate patch for the min-iter-count and a few > test cases. OK. Any opinions on the location of the isParallelLoop() check? Shall I put it to Loop so it is more widely accessible? I.e. Loop->isParallel(). -- Pekka

..., let's start with the 'parallel' semantics first, not > the vague ones. > > A conclusion of some kind for me to update the patch: > > 1) Rename the loop branch metadata back to llvm.loop.parallel. > > I'll add a definition of its semantics (as comments to Loop::isParallel()): Hello Pekka, I think it would be better to add a section to the LangRef: http://llvm.org/docs/LangRef.html#metadata A good comment would be helpful, too, but LangRef should be normative. Dmitri -- main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if (j){printf("%d\n&...

...be used for anything > during optimizations (as it's not safe to do so!). > Those are fair points and I can't say whether or not there are other potential users. Certainly clang could use custom loop metadata and the pass could live in its codegen. Another option is two make Loop::isParallel aware of both safe and unsafe parallel metadata and not requires translation at all. In practice, passes like reg2mem are not run so the concern goes away. Perhaps a single loop metadata is good enough for most uses? paul > -- > --Pekka

...fragile, and it's also uncertain if it's possible to implement it. IMHO, the best alternative presented so far is to have both metadata types and potentially exploit the mem.parallel_loop_access MD even if there were non-annotated instructions in the loop to *help* the dependency analysis. isParallel() would stay as is now in the patch, it can be used as a short cut check for a loop of which accesses all have the metadata (to skip the whole dependency checking). -- --Pekka

Dear all, Here's an updated version of the parallel loop metadata patch. It includes documentation for the new metadata types with a semantics description. -- Pekka -------------- next part -------------- A non-text attachment was scrubbed... Name: parallel-loop-metadata.patch Type: text/x-patch Size: 12972 bytes Desc: not available URL:

...on. 3. These patches are currently under review and I am incorporating changes as suggested by the Polly community. 4. Implemented first version of an interface to Polly's analysis passes- PolyhedralInfo pass (D21486 <http://reviews.llvm.org/D21486>). Implemented isParallel(Loop *) interface to check parallelism of a loop. Pending Work: 1. Complete the interface - PolyhederalInfo pass. Currently I am working on providing more interfaces to check whether a loop is vectorizable or not and to get loop trip count. - isVectorizable(Loop *L, *MinDe...

On 02/08/2013 07:02 PM, Sebastian Pop wrote: > Nadav Rotem wrote: >> >> On Feb 7, 2013, at 10:55 AM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: >> >>> Hi Nadav, >>> >>> On 02/07/2013 07:46 PM, Nadav Rotem wrote: >>>> Pekka suggested that we add two kind of metadata: llvm.loop.parallel >>>> (attached to each

...eläinen wrote: > On 01/28/2013 06:45 PM, Nadav Rotem wrote: >> I am okay with this patch, assuming that you follow the review of Tobias >> and Renato and provide a separate patch for the min-iter-count and a few >> test cases. > > OK. Any opinions on the location of the isParallelLoop() check? Shall I > put it to Loop so it is more widely accessible? I.e. Loop->isParallel(). > > -- > Pekka > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiu...

...arallel >> loops. >> >> It uses two types of metadata: >> llvm.loop.ignore_assumed_deps attached to the loop latch's >> branch instruction and llvm.mem.parallel_loop_access attached to >> all of the parallel loop's memory accesses. >> >> Loop::isParallel() checks these. If llvm.loop.ignore_assumed_deps >> is found, it ensures all the memory instructions inside the >> loop body have the llvm.mem.parallel_loop_access attached before >> returning true. >> >> Test included for the LoopVectorizer that uses this info to para...

Hi Paul, On 02/28/2013 09:30 PM, Redmond, Paul wrote: > I'd like to reopen the discussion on requiring the > llvm.mem.parallel_loop_access metadata. I understand the reason for the > metadata is to protect against transformations that may introduce unsafe > parallel memory accesses (the reg2mem example.) I'm wondering if perhaps we > can make the metadata more user-friendly

Hi Pekka, I am okay with this patch, assuming that you follow the review of Tobias and Renato and provide a separate patch for the min-iter-count and a few test cases. I think that it would be a good idea to start a new thread and to discuss the best way to annotate loops in LLVM. Thanks, Nadav On Jan 28, 2013, at 5:49 AM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: >

...ertain if > it's possible to implement it. > > IMHO, the best alternative presented so far is to have both metadata types > and potentially exploit the mem.parallel_loop_access MD even if there were > non-annotated instructions in the loop to *help* the dependency analysis. > isParallel() would stay as is now in the patch, it can be used as a short cut > check for a loop of which accesses all have the metadata (to skip the whole > dependency checking). > > -- > --Pekka > > _______________________________________________ > LLVM Developers mailing list &gt...

...ASLibary ? convertToBlasLibCall(Root) : applyBLIS(Root): Worklist.replace(Root, Optimized); return; } // Mid level: recognize stencils if (isStencil(Root)) ... // Mid level: Map to compute hierarchy (here: simd -> SMT -> core -> socket for CPUs) if (isParallel(Root) fitsWorkingSet(Root.getBody(), LLCSize) && && isParallel(Root.getPerfectlyNestedLoop(1)) && fitsWorkingSet(Root.getPerfectlyNestedLoop(2).getBody(), L2Size) && isParallel(Root.getPerfectlyNestedLoop(2)) && fitsWorkingSet(Root.g...

Hi Renato, On 01/28/2013 03:22 PM, Renato Golin wrote: > This seems an awfully specific check on a generic part of the code... If True. Perhaps the check is better encapsulated, e.g., in the Loop class? Or, if there's such thing as a loop-carried data dependency analyzer, the correct place could be there, as a trivial "no deps" analysis. > this metadata standard in any

----- Original Message ----- > From: "Nadav Rotem" <nrotem at apple.com> > To: "Pekka Jääskeläinen" <pekka.jaaskelainen at tut.fi> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Monday, January 28, 2013 10:45:36 AM > Subject: Re: [LLVMdev] [PATCH] parallel loop awareness to the LoopVectorizer > > Hi Pekka,

Hi, I've been working on clang codegen for #pragma ivdep and creating the llvm.mem.parallel_loop_access metadata seems quite difficult. The main problem is that there are so many places where loads and stores are created and all of them need to be changed when emitting a parallel loop. Note that creating llvm.loop.parallel is not a problem. One option is to modify IRBuilder to enable