similar to: [LLVMdev] Differences and Relationship between VLIW scheduler and VLIW packetizer?

Hi Yang, They have different implementations because they don't do the same thing and don't rely on the same structures. VLIW scheduling works on the SelectionDAG, right after the instruction selection, and it will schedule the DAG but it will not build any packet. The VLIW packetizer has been designed to work with machine instructions, using the ScheduleDAGInstr, and it does build

Hi, It seems the only one VLIW target Hexagon in LLVM 3.2 devel uses a straightforward way to emit its VLIW-style asm codes. It uses a list scheduler to schedule on DAG and a simple packetizer to wrap the emitted asm instructions. Both scheduling and packetizing work on basic blocks. so, is there any plan to implement better optimization methods such as trace scheduling, software pipelining, ...

Yang, There is work currently underway to add SW pipelining and some sort of global scheduling to Hexagon, but if there is some interest to it from other targets, it would be helpful to know. What is your involvement with this? Sergei Larin -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum. > -----Original Message----- > From: llvmdev-bounces at cs.uiuc.edu

Larin, Thank you for telling me about this. Our lab is planning to design a VLIW DSP and has to make a choice between GCC and LLVM, for which I take responsibility. As we all know that GCC's codes possess a long history and has a somewhat bad learning curve, I suggest choosing LLVM. It seems now the only drawback is its poor support for VLIW architecture. And so if we can count on

Yang, This might not be such a tough choice on engineering side - one of the LLVM differentiators is the ground-up, early introduced support for VLIW specific features... As for the help offer - thanks... I'll definitely keep that in mind. The best help right now would be to keep on trying new VLIW related features as they got merged to LLVM tree and provide feedback... and we do plan to

Hi Jonas, > It is interesting to find this in the ARM backend, considering your answer. The ARM backend doesn't use the DFA packetizer. It's only used by Hexagon. At this point, there is no plan to address thisin the DFA packetizer since none of the supported targets needthe functionality. Thanks -Anshu --- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,

Jonas, At this point, the DFA packetizer models a simple VLIW architecture and does not accommodate multiple stages. That's the reason for the behavior you're seeing. -Anshu --- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation *From:*llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] *On Behalf Of *Jonas

Hi Anshu, Would there be any interest in extending this algorithm to handling more extensive models, such as VLIW scheduling based on FU's and bundle space... ie handle multiple stages ? I might do it and commit, if there is acceptance and guidance... Jonas ________________________________ From: Anshuman Dasgupta [mailto:adasgupt at codeaurora.org] Sent: Tuesday, February 12, 2013 4:47 PM

On Aug 9, 2012, at 10:09 AM, Sergei Larin <slarin at codeaurora.org> wrote: > Yang, > > This might not be such a tough choice on engineering side - one of the > LLVM differentiators is the ground-up, early introduced support for VLIW > specific features… Actually, LLVM lacked support for VLIW until fairly recently, and it has relatively few VLIW-specific features. Dan

Hi, I would like to inform the community that I'm releasing the backend for tile64 I developed in the past several months. It can be downloaded from http://pnyf.inf.elte.hu/juhda/projects/tilera/ The version for LLVM 3.1 is a minimalist functioning implementation. Now I am working on utilizing the VLIW packetizer of LLVM, and other improvements are planned for the future. I would be

Sergei, Thank you for your attention. My target is a custom VLIW DSP. I am not sure dependency dag is correct when it gets scheduled and packetized. Months ago, I submitted a bug at http://llvm.org/bugs/show_bug.cgi?id=17894 which explained more details. I am not sure my understanding of this bug is proper, but modified my local codes this way and it works for my target when scheduling and

But we are really striving to change it fast :) Dan, My comparative point was that LLVM has a greater potential to accommodate VLIW going forward than GCC does at this point. Would you agree to that? Sergei -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum. > -----Original Message----- > From: Dan Gohman [mailto:gohman at apple.com] > Sent: Friday, August 10,

> On Nov 9, 2015, at 10:49 AM, Rail Shafigulin <rail at esenciatech.com> wrote: > > On Mon, Nov 9, 2015 at 10:31 AM, Hal Finkel <hfinkel at anl.gov <mailto:hfinkel at anl.gov>> wrote: > ----- Original Message ----- > > From: "Rail Shafigulin via llvm-dev" <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> > > To:

On Wed, Sep 05, 2012 at 07:48:48PM +0200, JUHASZ David wrote: > Hi, > > I would like to inform the community that I'm releasing the backend for > tile64 I developed in the past several months. It can be downloaded from > > http://pnyf.inf.elte.hu/juhda/projects/tilera/ > > The version for LLVM 3.1 is a minimalist functioning implementation. Now > I am working on

Hi, I looked a bit through the mail archives, and found this question answered in Oct 2011 (see below). It is interesting to find this in the ARM backend, considering your answer. Can you give more information about for example is this a temporary deficiency in the DFAPacketizer? What is the IIC_iMOVi itinerary doing below? Thanks, Jonas Thu Oct 6 15:11:25 CDT 2011: Hello Hal. > Is there

Kun, Thanks for the reply. I looked at it, but wasn't able to find where actual instruction bundling takes place, i.e. where exactly in the code they pack instruction into a single bundle. Do you know where it is done? I would really appreciate any pointers. Thanks. On Fri, Sep 25, 2015 at 4:37 PM, Kun Ling <kunling at lingcc.com> wrote: > Hi Rail, > For the VLIW support,

----- Original Message ----- > From: "Rail Shafigulin via llvm-dev" <llvm-dev at lists.llvm.org> > To: "llvm-dev" <llvm-dev at lists.llvm.org> > Sent: Monday, November 9, 2015 10:09:07 AM > Subject: Re: [llvm-dev] Is there a way to convert between SchedMachineModel and Itineraries? > > > Anybody? Does anyone at all know how to do it? There is

Hi, Thanks for your explanations! How is the big picture for supporting in-order VLIW architectures and the like though? I am asking because I am currently implementing instruction scheduling in our own backend for our custom Patmos processor, for which I need to support both branch delay slots and bundles, some restrictions regarding bundles. For the moment, I am quite happy with a simple

Is there a way to convert between SchedMachineModel and Itineraries? I was trying to write a very simple VLIW packetizer (Hexagon was my starting point). It turns out that current DFAPacketizer is using itineraries, but my schedule is based on SchedMachineModel (I was recommended to use it since the itineraries are being phased out). I was wondering if there is an automated tool that would

Hi paulr, Thank you for your response :) Hi Krzysztof, This is really helpful! Thank you for your guidance!! I would like to trace the Hexagon's llvm implementation. I am very interested on how Hexagon implement instruction pattern matching, instruction scheduling, and register allocation, could you give me some suggestions or reading lists to help me understand Hexagon's llvm