similar to: RFC: Supporting the RISC-V vector extension in LLVM

Hi, Comments below On 13 April 2018 at 16:52, Robin Kruppe <robin.kruppe at gmail.com<mailto:robin.kruppe at gmail.com>> wrote: On 13 April 2018 at 14:37, Graham Hunter <Graham.Hunter at arm.com<mailto:Graham.Hunter at arm.com>> wrote: Hi, Nice to see another group tackling length agnostic vectorization :) I'm still reading through all the details, but I do have one

On 13 April 2018 at 16:52, Robin Kruppe <robin.kruppe at gmail.com> wrote: > On 13 April 2018 at 14:37, Graham Hunter <Graham.Hunter at arm.com> wrote: > >> Hi, >> >> Nice to see another group tackling length agnostic vectorization :) >> >> I'm still reading through all the details, but I do have one initial >> question related to the

I'm just going to add Kristof here since ARM is looking to add SVE here and this overlaps quite a bit with their goals. -eric On Wed, Apr 11, 2018 at 2:45 AM Robin Kruppe via llvm-dev < llvm-dev at lists.llvm.org> wrote: > RISC-V is an open and free instruction set architecture (ISA) used in > numerous domains in industry and research. The vector extension (short: >

Hi, i am the main author of RV, the Region Vectorizer (github.com/cdl-saarland/rv). I want to share our standpoint as potential users of the proposed vector-length agnostic IR (RISC-V, ARM SVE). -- support for `llvm.experimental.vector.reduce.*` intrinsics -- RV relies heavily on predicate reductions (`or` and `and` reduction) to tame divergent loops and provide a vector-length agnostic

On 27 November 2016 at 16:51, Amara Emerson <amara.emerson at gmail.com> wrote: > There is nothing to stop other targets from using > stepvector/seriesvector. In fact for wide vector targets, often the IR > constant for representing a step vector is explicitly expressed as > <i32 0, i32 1, i32 2..> and so on (this gets really cumbersome when > your vector length is

On Tue, Oct 1, 2019 at 11:08 AM Graham Hunter <Graham.Hunter at arm.com> wrote: > Hi Luke, hi graham, thanks for responding in such an informative fashion. > > On 1 Oct 2019, at 09:21, Luke Kenneth Casson Leighton via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > typedef vec4 float[4]; // SEW=32,LMUL=4 probably > > static vec4 globalvec[1024]; // vscale ==

On Tue, Oct 1, 2019 at 8:08 AM Robin Kruppe <robin.kruppe at gmail.com> wrote: > > Hello Jacob and Luke, > > First off, even if a dynamically changing vscale was truly necessary > for RVV or SV, this thread would be far too late to raise the question. > That vscale is constant -- that the number of elements in a scalable > vector does not change during program execution

Hi, > On 6 Jun 2018, at 17:36, David A. Greene <dag at cray.com> wrote: > > Graham Hunter via llvm-dev <llvm-dev at lists.llvm.org> writes: > >>> Ok, now I understand what you're getting at. A ConstantExpr would >>> encapsulate this computation. We alreay have "non-static-constant" >>> values for ConstantExpr like sizeof and

Hi Robin, responses inline. -Graham > On 11 Jun 2018, at 16:47, Robin Kruppe <robin.kruppe at gmail.com> wrote: > > Hi Graham, > Hi David, > > glad to hear other people are thinking about RVV codegen! > > On 7 June 2018 at 18:10, Graham Hunter <Graham.Hunter at arm.com> wrote: >> >> Hi, >> >>> On 6 Jun 2018, at 17:36, David A.

On Wed, 2 Oct 2019 at 05:09, Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote: > > My general feeling on this then is that both RVV and SV should avoid using > vscale. > > In the case of RVV, MVL is a hardware defined constant that is never > *intended* to be known by applications. There's no published detection > mechanism. Loops are supposed to be designed

Hi Luke, > was it intentional to leave out both jacob and myself? > [...] > if that was a misunderstanding or an oversight i apologise for raising it. It was definitely not my intention to be non-inclusive, my apologies if that seemed the case! > can i therefore recommend a change, here: > [...] > "This patch adds vscale as a symbolic constant to the IR, similar to >

On Thu, Jan 31, 2019 at 4:05 PM Philip Reames via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Do such architectures frequently have arithmetic operations on the mask registers? (i.e. can I reasonable compute a conservative length given a mask register value) If I can, then having a mask as the canonical form and re-deriving the length register from a mask for a sequence of

Hi, I would like to restart the conversation regarding adding SVE support to LLVM. This time I am framing things from the code generation point of view because our immediate priority is llvm-mc support rather than auto-vectorisation. Can you please review the following text outlining MVT changes we would like to make so SVE instructions can be added to the AArch64 Target. My overriding

Hi, Now that Sander has committed enough MC support for SVE, here's an updated RFC for variable length vector support with a set of 14 patches (listed at the end) to demonstrate code generation for SVE using the extensions proposed in the RFC. I have some ideas about how to support RISC-V's upcoming extension alongside SVE; I'll send an email with some additional comments on

On 28 November 2016 at 09:15, Alex Bradbury <asb at asbradbury.org> wrote: > The RISC-V vector proposal is still in the development stage, but it > will inevitably be vector length agnostic much like Hwacha. Krste gave > a talk about his proposal for the 'V' extension last year > <https://riscv.org/wp-content/uploads/2015/06/riscv-vector-workshop-june2015.pdf> >

Hi, Looking at the language reference, vscale is an integer. This might pose a problem for fractional vscale. Furthermore, I believe that vscale is constant throughout the life of the program; so if RISC-V vscale can vary from instruction to instruction that may also be problematic unless you can just commit to one specific value of vscale. Also, I had a question about your table. Based

Hi David, >>> The name "getSizeExpressionInBits" makes me think that a Value >>> expression will be returned (something like a ConstantExpr that uses >>> vscale). I would be surprised to get a pair of integers back. Do >>> clients actually need constant integer values or would a ConstantExpr >>> sufffice? We could add a ConstantVScale or

On 2/5/19 1:27 AM, Philip Reames via llvm-dev wrote: > > On 1/31/19 4:57 PM, Bruce Hoult wrote: >> On Thu, Jan 31, 2019 at 4:05 PM Philip Reames via llvm-dev >> <llvm-dev at lists.llvm.org> wrote: >>> Do such architectures frequently have arithmetic operations on the >>> mask registers?  (i.e. can I reasonable compute a conservative >>> length

I have posted a patch that switches the API to one that supports this (yet non-existent functionality) earlier: https://reviews.llvm.org/D24631 The comments from that were incorporated into the following RFC. Motivation: Certain targets feature "variable-sized" registers, i.e. a situation where the register size can be configured by a hardware switch. A common instruction set

On Tuesday, October 1, 2019, Jacob Lifshay <programmerjake at gmail.com> wrote: > On Mon, Sep 30, 2019 at 2:30 AM Sander De Smalen via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > > > > I've posted two patches on Phabricator to add support for VScale in LLVM. Excellent! > > > > A brief recap on `vscale`: > > The scalable vector type in