similar to: [LLVMdev] [PATCH] parallel loop metadata

Hi Pekka, On 2013-02-28, at 4:21 PM, Pekka Jääskeläinen wrote: > 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

On Fri, Feb 8, 2013 at 10:10 AM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > On 02/08/2013 04:26 PM, Daniel Berlin wrote: >> >> I'd love to see example cases where the pair analysis is the >> difficulty, rather than the access analysis of any single memory piece >> being the difficulty. > > > I'm not completely sure what you mean,

----- Original Message ----- > From: "Pekka Jääskeläinen" <pekka.jaaskelainen at tut.fi> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Nadav Rotem" <nrotem at apple.com>, "Tobias Grosser" <tobias at grosser.es>, "CVS Commit Messages for LLVM repository" > <llvm-commits at cs.uiuc.edu>, "Sebastian

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

On Fri, Feb 8, 2013 at 9:16 AM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > Hi Renato, > > > On 02/08/2013 03:07 PM, Renato Golin wrote: >> >> In this case, I'd prefer metadata on the variables that are assumed not >> to alias, like the restrict keyword. > >> >> >> It seems to me that having metadata on the loop basic

On 01/28/2013 12:58 PM, Pekka Jääskeläinen wrote: > Hi, > > Attached is a patch which uses a simple "parallel_loop" metadata attached > to the loop branch instruction in the loop latch for skipping > cross-iteration > memory dependency checking in the LoopVectorizer. This was briefly > discussed > in the email thread "LoopVectorizer in OpenCL C work group

Hello all, Thanks for the comments. Attached is a new version with Tobias' and Sebastian's (final?) comments addressed. Any further comments are appreciated. Nadav suggested a request for comments in llvmdev before committing it. In order to describe the current idea of the parallel loop metadata, I think it's easiest to just copy-paste the documentation I wrote for this patch so

On Feb 8, 2013, at 12:28 PM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > On 02/08/2013 08:20 PM, Tobias Grosser wrote: >> That sounds elegant and seems to solve the correctness problems. > > There is no big difference here except that the memory instructions > would not need the metadata. > > I do not think the abundance of metadata is really the

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

On 02/08/2013 04:26 PM, Daniel Berlin wrote: > I'd love to see example cases where the pair analysis is the > difficulty, rather than the access analysis of any single memory piece > being the difficulty. I'm not completely sure what you mean, but is there really a difference between doing "pair analysis" across multiple iterations of the same instruction than doing it

On Wed, Jan 30, 2013 at 12:35 PM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > Thank you all for comments, > > > On 01/30/2013 11:22 AM, David Tweed wrote: >> >> 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

Hi Renato, On 02/08/2013 03:07 PM, Renato Golin wrote: > In this case, I'd prefer metadata on the variables that are assumed not > to alias, like the restrict keyword. > > It seems to me that having metadata on the loop basic blocks, since they > can be invalidated, will not help that much with the vectorizer more > than specific annotation on specific values (which are

On 02/07/2013 11:49 PM, 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 loop latch) and llvm.mem.parallel (attached to each

On 02/08/2013 08:20 PM, Tobias Grosser wrote: > That sounds elegant and seems to solve the correctness problems. There is no big difference here except that the memory instructions would not need the metadata. I do not think the abundance of metadata is really the main problem, but what to do with passes that do not know about parallel loops. How to minimize the changes needed to make the

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

Thank you all for comments, On 01/30/2013 11:22 AM, David Tweed wrote: > 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 >

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

OK, I updated the text to LangRef in r209507 after some editing. On 05/11/2014 12:36 PM, Pekka Jääskeläinen wrote: > Hi, > > This looks good to me except that the first sentence > could already include "that refer to the same loop" or > similar. > > I could imagine that e.g. loop invariant code motion, > if applied to a parallel loop could hoist code out of >

It sounds like a good idea to move the method in to Loop. Is there a naming scheme for metadata? I think llvm.loop.* would be helpful for loop-specific metadata. As for parallel I think it is a little too generic. If ivdep are the semantics you're going for I'd use that. paul On 2013-01-28, at 12:03 PM, Pekka Jääskeläinen wrote: > On 01/28/2013 06:45 PM, Nadav Rotem wrote: >>

----- Original Message ----- > From: "Pekka Jääskeläinen" <pekka.jaaskelainen at tut.fi> > To: "Paul Redmond" <paul.redmond at intel.com> > Cc: "Hal Finkel" <hfinkel at anl.gov>, "Tobias Grosser" <tobias at grosser.es>, "<llvmdev at cs.uiuc.edu>" > <llvmdev at cs.uiuc.edu> > Sent: Tuesday, March 5,