similar to: Oddity w/MachineBlockPlacement and Loops

I've been playing with approaches to getting better optimization of loops which contain infrequently executed slow paths. I've gotten as far as throwing together a proof of concept implementation of a profile guided optimization to separate a single loop with multiple latches into a loop nest, but I want to get feedback from interested parties before investing much more effort. The

On Feb 4, 2014, at 4:36 PM, Andrew Trick <atrick at apple.com> wrote: > > On Feb 4, 2014, at 4:07 PM, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote: > >> >> On Feb 3, 2014, at 12:13 AM, Andrew Trick <atrick at apple.com> wrote: >> >>> On Feb 2, 2014, at 6:55 PM, Chandler Carruth <chandlerc at gmail.com> wrote: >>>

On Feb 3, 2014, at 12:13 AM, Andrew Trick <atrick at apple.com> wrote: > On Feb 2, 2014, at 6:55 PM, Chandler Carruth <chandlerc at gmail.com> wrote: > >> On Sun, Feb 2, 2014 at 6:18 PM, Andrew Trick <atrick at apple.com> wrote: >> >> On Feb 2, 2014, at 2:13 AM, Chandler Carruth <chandlerc at gmail.com> wrote: >> >> > Right now,

On 01/07/2015 05:33 PM, Chandler Carruth wrote: > How does this compare with classical approaches of loop peeling, > partitioning, fission, or whatever you might call it? I'm still developing a good sense for this, but let me lay out some observations. Fair warning, this is going to be long and rambling. Let's start with a toy example: while(c) { x = this->x; y =

On 6/30/2017 7:48 AM, Balaram Makam via llvm-dev wrote: > > Edit. Predecessor -> successor. > > *From:* llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] *On Behalf > Of *Balaram Makam via llvm-dev > *Sent:* Friday, June 30, 2017 10:47 AM > *To:* llvm-dev at lists.llvm.org > *Subject:* [llvm-dev] LoopSimplify pass prevents loop unrolling > > Hi All, > >

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

On Sun, Feb 2, 2014 at 6:18 PM, Andrew Trick <atrick at apple.com> wrote: > > On Feb 2, 2014, at 2:13 AM, Chandler Carruth <chandlerc at gmail.com> wrote: > > > Right now, all profile information is funneled through two analysis > passes prior to any part of the optimizer using it. > > > > First, we have BranchProbabilityInfo, which provides a simple

Hi all, I would like to propose an improvement of the “almost dead” block elimination in Transforms/Local.cpp so that it will preserve the canonical loop form for loops with a volatile iteration variable. *** Problem statement Nested loops in LCALS Subset B (https://codesign.llnl.gov/LCALS.php) are not vectorized with LLVM -O3 because the LLVM loop vectorizer fails the test whether the loop

<mehdi.amini at apple.com>, Bcc: Subject: Re: [llvm-dev] [RFC][PIR] Parallel LLVM IR -- Stage 0 -- IR extension Reply-To: In-Reply-To: <20170224221713.GA931 at arch-linux-jd.home> Ping. PS. Are there actually people interested in this? We will continue working anyway but it might not make sense to put it on reviews and announce it on the ML if nobody cares. On 02/24,

An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200320/34cdec77/attachment.html> -------------- next part -------------- Hi all, I have encountered some issues with the preservation of the location of llvm.loop metadata (containing optimisation hints), and would appreciate some feedback on the issue. The IR language description states that

> On Jan 7, 2015, at 5:33 PM, Chandler Carruth <chandlerc at google.com> wrote: > > > On Wed, Jan 7, 2015 at 5:19 PM, Philip Reames <listmail at philipreames.com <mailto:listmail at philipreames.com>> wrote: > I've been playing with approaches to getting better optimization of loops which contain infrequently executed slow paths. I've gotten as far as

So I have a loop with two blocks, a header (which points to return and latch) and a latch (which points to return and header). I have inserted a few new blocks, called H and F. Header now points to H and latch. Latch now points to F. H points to F. F points to Header and return. The PHI Nodes have been updated in Header accordingly, now coming from the preheader and F (instead of latch). My

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

Hi, I want to insert a conditional branch in the middle of a basic block. To that end, I am doing these steps: (1) Split the basic block: bb->splitBasicBlock() (2) Remove the old terminator: succ->removePredecessor(bb) bb->getTerminator()->getParent() (3) Adding a new terminator: BranchInst::Create(ifTrue, ifFalse, cnd, "", bb); That seems to work, but later passes

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Hyojin Sung" <hsung at us.ibm.com>, llvmdev at cs.uiuc.edu > Sent: Thursday, July 16, 2015 1:06:03 AM > Subject: Re: [LLVMdev] Improving loop vectorizer support for loops > with a volatile iteration

Hi All, In the attached test case there, is an unnested loop with 2 iterations. The loop latch block is terminated by an unconditional branch, so simplifycfg folds the almost empty latch block into its predecessor which is the loop header. This results in an additional backedge in the CFG, so when LoopRotate pass is called it canonicalizes the loop into a nested loop. However, now the loop

> 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: >>

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hyojin Sung" <hsung at us.ibm.com>, llvmdev at cs.uiuc.edu > Sent: Wednesday, July 15, 2015 7:34:54 PM > Subject: Re: [LLVMdev] Improving loop vectorizer support for loops > with a volatile iteration variable > On Wed, Jul 15, 2015 at 12:55 PM Hyojin Sung

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 *