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Dear all, This RFC proposes three new LLVM IR instructions to express high-level parallel constructs in a simple, low-level fashion. For this first stage we prepared two commits that add the proposed instructions and a pass to lower them to obtain sequential IR. Both patches have be uploaded for review [1, 2]. The latter patch is very simple and the former consists of almost only mechanical

A quick update, we have been looking through all LLVM passes to identify the impact of "IR-region annotation", and interaction issues with the rest of LoopOpt and scalarOpt, e.g. interaction with vectorization when you have schedule(simd:guided: 64). What are the common properties for optimizer to know on IR-region annotations. We have our implementation working from O0, O1, O2 to O3.

".... the problem Mehdi pointed out regarding the missed initializations of array elements, did you comment on that one yet?" What is the initializations of array elements question? I don't remember this question. Please refresh my memory. Thanks. I thought Mehdi's question is more about what are attributes needed for these IR-annotation for other LLVM pass to understand and

> On Mar 8, 2017, at 10:55 AM, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> >> On Mar 8, 2017, at 5:36 AM, Johannes Doerfert <doerfert at cs.uni-saarland.de> wrote: >> >> <mehdi.amini at apple.com>, >> Bcc: >> Subject: Re: [llvm-dev] [RFC][PIR] Parallel LLVM IR -- Stage 0 -- IR extension >> Reply-To: >>

On 03/08/2017 12:44 PM, Johannes Doerfert wrote: > I don't know who pointed it out first but Mehdi made me aware of it at > CGO. I try to explain it shortly. > > Given the following situation (in pseudo code): > > alloc A[100]; > parallel_for(i = 0; i < 100; i++) > A[i] = f(i); > > acc = 1; > for(i = 0; i < 100; i++) > acc = acc *

I assume the referring case is something like below, right? #pragma omp parallel num_threads(n) { #pragma omp critical { x = x + 1; } } If that is the case, the programmer is already writing the code that is not "serial equivalent". Our representation for parallelizer is %t = @llvm.region.entry()["omp.parallel"(),

The IR-region annotation we proposed is as below, there is no @llvm.parallel.for.iterator()..... There is no change to loop CFG. alloc A[100]; %t = call token @llvm.region.entry()["parallel.for"()] for(i = 0; i < 100; i++) { a[i] = f(i); } @llvm.region.exit(%t)() ["end.parallel.for"()] Xinmin -----Original Message----- From: Johannes Doerfert

> On Mar 8, 2017, at 11:50 AM, Hal Finkel <hfinkel at anl.gov> wrote: > > > On 03/08/2017 01:24 PM, Tian, Xinmin wrote: >> I assume the referring case is something like below, right? >> >> #pragma omp parallel num_threads(n) >> { >> #pragma omp critical >> { >> x = x + 1; >> } >> }

Hi Johannes, > I am especially curious where you get your data from. Tapir [0] (and to > some degree PIR [1]) have shown that, counterintuitively, only a few changes > to LLVM passes are needed. Tapir was recently used in an MIT class with a > lot of students and it seemed to work well with only minimal changes > to analysis and especially transformation passes. TAPIR is an

On Thu, Jan 19, 2017 at 1:12 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > > On Jan 19, 2017, at 12:04 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > > > > On Thu, Jan 19, 2017 at 11:46 AM, Mehdi Amini via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> >> > On Jan 19, 2017, at 11:36 AM, Adve, Vikram Sadanand via llvm-dev

This is an RFC to add analyses and transformation passes into LLVM to optimize programs based on an abstract notion of a parallel region. == this is _not_ a proposal to add a new encoding of parallelism == We currently perform poorly when it comes to optimizations for parallel codes. In fact, parallelizing your loops might actually prevent various optimizations that would have been applied

On 01/11, Daniel Berlin via llvm-dev wrote: > > > > def int_experimental_directive : Intrinsic<[], [llvm_metadata_ty], > > [IntrArgMemOnly], > > "llvm.experimental.directive">; > > > > def int_experimental_dir_qual : Intrinsic<[], [llvm_metadata_ty], > > [IntrArgMemOnly], > >

Hi Sanjoy, Yes, that's exactly what we have been looking at recently here, but the region tags seem to make it possible to express the control flow as well, so I think we could start with reg ions+metadata, as Hal and Xinmin proposed, and then figure out what needs to be first class instructions. --Vikram Adve > On Jan 19, 2017, at 11:03 PM, Sanjoy Das <sanjoy at

A Proposal for adding an experimental IR-level region-annotation infrastructure ============================================================================= Hal Finkel (ANL) and Xinmin Tian (Intel) This is a proposal for adding an experimental infrastructure to support annotating regions in LLVM IR, making use of intrinsics and metadata, and a generic analysis to allow transformations to

Hello, Below is a proposal for a GSoC project that I would like to work on this year. Your input and feedback is much appreciated. Background: ========= My name is Kareem Ergawy and I currently work as part of the PIR project. PIR is an extension of the IR to support fork-join parallelism that is currently under review [1, 2, 3, 4]. Goals: ===== As a GSoC project, here I propose an

Dear community, In preparation for the BoF on Parallel IR at the US developers meeting we would like to collect feedback from the whole community. The concerns, ideas, etc. will be summarized in the BoF and should provide a good starting point for a discussion. We know that over the years the topic of a parallel extension for LLVM was discussed on the mailing list [0, 1, 2], workshops [3, 4] or

On Thu, Jan 19, 2017 at 11:46 AM, Mehdi Amini via llvm-dev < llvm-dev at lists.llvm.org> wrote: > > > On Jan 19, 2017, at 11:36 AM, Adve, Vikram Sadanand via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > > Hi Johannes, > > > >> I am especially curious where you get your data from. Tapir [0] (and to > >> some degree PIR [1]) have

Hello, I want to know does LLVM has support for MPI Programming Model? Can we do LLVM optimizations in MPI Programs? Regards -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161017/dd645f09/attachment.html>

On 01/19/2017 03:36 PM, Mehdi Amini via llvm-dev wrote: > >> On Jan 19, 2017, at 1:32 PM, Daniel Berlin <dberlin at dberlin.org >> <mailto:dberlin at dberlin.org>> wrote: >> >> >> >> On Thu, Jan 19, 2017 at 1:12 PM, Mehdi Amini<mehdi.amini at apple.com >> <mailto:mehdi.amini at apple.com>>wrote: >> >> >>>

Hi, I'm going to club together some responses. I agree that outlining function sub-bodies and passing in the function pointers to said outlined bodies to OpenMP helpers lets us correctly implement the semantics we need. However, unless I severely misunderstood the thread, I thought the key idea was to move *away* from that representation and towards a representation that _allows_