[PATCH 00/13] Add support for the T-Head vendor extensions

Philipp Tomsich philipp.tomsich@vrull.eu
Thu Sep 22 11:08:44 GMT 2022


I have write access and will do the push, after approval.

Thanks,
Philipp.

On Sun 18. Sep 2022 at 08:51, Christoph Müllner <christoph.muellner@vrull.eu>
wrote:

>
>
> On Fri, Sep 16, 2022 at 11:36 AM Nelson Chu <nelson@rivosinc.com> wrote:
>
>> Hi Christoph,
>>
>>
>> On Tue, Sep 6, 2022 at 8:22 PM Christoph Muellner
>> <christoph.muellner@vrull.eu> wrote:
>> >
>> > From: Christoph Müllner <christoph.muellner@vrull.eu>
>> >
>> > This series introduces support for the T-Head vendor extensions,
>> > which are implemented e.g. in the XuanTie C906 and XuanTie C910
>> > processors:
>> > * XTheadBa
>> > * XTheadBb
>> > * XTheadBs
>> > * XTheadCmo
>> > * XTheadCondMov
>> > * XTheadFMemIdx
>> > * XTheadMac
>> > * XTheadMemIdx
>> > * XTheadMemPair
>> > * XTheadSync
>> >
>> > The xthead* extensions are documented here:
>> >
>> https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.0.0/xthead-2022-09-05-2.0.0.pdf
>> >
>> > The "th." instruction prefix prevents future conflicts with standard
>> > extensions and has been documentented in a PR for the RISC-V toolchain
>> > conventions:
>> >   https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
>> >
>> > The goal of this patchset is to provide access to these instruction
>> > so that compilers/users can optimize SW accordingly.
>> >
>> > Note, that the T-Head vendor extensions do not contain all
>> > vendor-specific
>> > functionality of the T-Head SoCs (e.g. no vendor-specific CSRs are
>> > included).
>> > Instead the extensions cover coherent functionality, that is exposed to
>> > S and U mode.
>> >
>> > To enable the extensions above, the following two methods are possible:
>> > * add the extension to the arch string (e.g.
>> > * -march=rv64gc_xtheadcmo_xtheadsync)
>> > * implicitly select the extensions via CPU selection (e.g.
>> > * -mcpu=thead-c910)
>> >
>> > The patchset attempts to minimize code changes in generic/infrastructure
>> > code. All patches in this series come with tests to avoid future
>> regressions.
>> >
>> > Christoph Müllner (13):
>> >   RISC-V: Add generic support for vendor extensions
>> >   RISC-V: Add T-Head CMO vendor extension
>> >   RISC-V: Add T-Head SYNC vendor extension
>> >   RISC-V: Add support for arbitrary immediate encoding formats
>> >   RISC-V: Add T-Head Bitmanip vendor extension
>> >   RISC-V: Add T-Head CondMov vendor extension
>> >   RISC-V: Add T-Head MAC vendor extension
>> >   RISC-V: Add T-Head FMemIdx vendor extension
>> >   RISC-V: Add T-Head MemIdx vendor extension
>> >   RISC-V: Add support for literal instruction arguments
>> >   RISC-V: Add T-Head MemPair vendor extension
>>
>> There are three minor issues,
>>
>> 1. Probably need to add new extension support in
>> riscv_multi_subset_supports_ext, although it is just used for
>> reporting better error messages.
>>
>
> OK, will do.
>
>
>> 2. The operand L seems only to be used for t-head for now, so it
>> should be still a vendor operand, named with the X prefix probably
>> better.
>>
>
> You mean Xl (additionally to Xs and Xu)?
>
>
>> 3. I remember Lifang mentioned before that we should add these vendor
>> stuff based on the vendor infra in the integration branch, and that's
>> what I asked him to rebase his patches  to there before, since the
>> previous policy cannot accept vendor stuff on master branch.  But now
>> I think most of us agree to accept t-head extensions on mainline
>> directly, so I figured these things cannot be blocked by the vendor
>> infra and cannot be committed.  That doesn't mean we don't need the
>> vendor infra, that means we can support the vendor infra later if me
>> or someone have time to move them back to mainline.
>>
>> Therefore, these patches look good to me for now, thank you very much
>> for spending so much time to implement these.  But personally, I think
>> we should get the approval from the T-Head guys at least.  Btw, If
>> these implementations are referred to and based on the integration
>> branch, then I think it would be better to keep at least the
>> co-authors there in the commit message here; if these patches are
>> re-write without referring to the implementation from the integration
>> branch, then I need to apologize to them, because I asked them to
>> rewrite their patches over there, and cannot be committed to mainline
>> at that time...
>>
>
> The patches were written from scratch.
> Note, that before writing this series, we (T-Head and Vrull) worked
> together
> on grouping the instructions into individual extensions (and dropping less
> important parts like the vendor-specific CSRs).
> I'll add a Co-developed-by to the Xs/Xu patch as this was Lifang's idea.
> Also note, that the patches have been reviewed by T-Head (Lifang)
> before sending them to the list.
>
>
>>
>> >   riscv: gas: Add command line option '-mcpu=' to specify the CPU
>> >   riscv: Add T-Head entries for the -mcpu= flag
>>
>> Not sure if it is necessary to add -mcpu in assembler, since the
>> compiler should recognize -mcpu, and will expand it to the correct
>> extensions to assembler.  If there are no objections for a period of
>> time, then please go ahead and commit these.
>>
>
> I won't be able to push as I don't have write access.
> I'll send a v2 with the requested changes.
>
> Thank you for the review!
>
>
>>
>> Thank you very much
>> Nelson
>>
>> >  bfd/elfxx-riscv.c                             |  39 ++-
>> >  gas/config/tc-riscv.c                         | 127 +++++++
>> >  gas/doc/c-riscv.texi                          |  70 ++++
>> >  gas/testsuite/gas/riscv/mcpu-fail-unknown.d   |   3 +
>> >  gas/testsuite/gas/riscv/mcpu-fail-unknown.l   |   2 +
>> >  gas/testsuite/gas/riscv/mcpu-ok-c906.d        |   6 +
>> >  gas/testsuite/gas/riscv/mcpu-ok-c910.d        |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-ba-fail.d     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-ba-fail.l     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-ba-fail.s     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-ba.d          |  13 +
>> >  gas/testsuite/gas/riscv/x-thead-ba.s          |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-bb-fail.d     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-bb-fail.l     |   7 +
>> >  gas/testsuite/gas/riscv/x-thead-bb-fail.s     |   7 +
>> >  gas/testsuite/gas/riscv/x-thead-bb.d          |  30 ++
>> >  gas/testsuite/gas/riscv/x-thead-bb.s          |  22 ++
>> >  gas/testsuite/gas/riscv/x-thead-bs-fail.d     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-bs-fail.l     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-bs-fail.s     |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-bs.d          |  14 +
>> >  gas/testsuite/gas/riscv/x-thead-bs.s          |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-cmo-fail.d    |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-cmo-fail.l    |  22 ++
>> >  gas/testsuite/gas/riscv/x-thead-cmo-fail.s    |  22 ++
>> >  gas/testsuite/gas/riscv/x-thead-cmo.d         |  30 ++
>> >  gas/testsuite/gas/riscv/x-thead-cmo.s         |  22 ++
>> >  gas/testsuite/gas/riscv/x-thead-condmov.d     |  11 +
>> >  gas/testsuite/gas/riscv/x-thead-condmov.s     |   3 +
>> >  .../gas/riscv/x-thead-fmemidx-fail.d          |   3 +
>> >  .../gas/riscv/x-thead-fmemidx-fail.l          |  18 +
>> >  .../gas/riscv/x-thead-fmemidx-fail.s          |  17 +
>> >  gas/testsuite/gas/riscv/x-thead-fmemidx.d     |  25 ++
>> >  gas/testsuite/gas/riscv/x-thead-fmemidx.s     |  17 +
>> >  gas/testsuite/gas/riscv/x-thead-mac.d         |  15 +
>> >  gas/testsuite/gas/riscv/x-thead-mac.s         |   7 +
>> >  gas/testsuite/gas/riscv/x-thead-memidx-fail.d |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-memidx-fail.l |  14 +
>> >  gas/testsuite/gas/riscv/x-thead-memidx-fail.s |  14 +
>> >  gas/testsuite/gas/riscv/x-thead-memidx.d      |  53 +++
>> >  gas/testsuite/gas/riscv/x-thead-memidx.s      |  48 +++
>> >  .../gas/riscv/x-thead-mempair-fail.d          |   3 +
>> >  .../gas/riscv/x-thead-mempair-fail.l          |  30 ++
>> >  .../gas/riscv/x-thead-mempair-fail.s          |  30 ++
>> >  gas/testsuite/gas/riscv/x-thead-mempair.d     |  14 +
>> >  gas/testsuite/gas/riscv/x-thead-mempair.s     |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-sync-fail.d   |   3 +
>> >  gas/testsuite/gas/riscv/x-thead-sync-fail.l   |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-sync-fail.s   |   6 +
>> >  gas/testsuite/gas/riscv/x-thead-sync.d        |  14 +
>> >  gas/testsuite/gas/riscv/x-thead-sync.s        |   6 +
>> >  include/opcode/riscv-opc.h                    | 326 ++++++++++++++++++
>> >  include/opcode/riscv.h                        |  27 ++
>> >  opcodes/riscv-dis.c                           |  44 +++
>> >  opcodes/riscv-opc.c                           | 155 +++++++++
>> >  55 files changed, 1394 insertions(+), 2 deletions(-)
>> >  create mode 100644 gas/testsuite/gas/riscv/mcpu-fail-unknown.d
>> >  create mode 100644 gas/testsuite/gas/riscv/mcpu-fail-unknown.l
>> >  create mode 100644 gas/testsuite/gas/riscv/mcpu-ok-c906.d
>> >  create mode 100644 gas/testsuite/gas/riscv/mcpu-ok-c910.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-ba-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-ba-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-ba-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-ba.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-ba.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bb-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bb-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bb-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bb.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bb.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bs-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bs-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bs-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bs.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-bs.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-cmo-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-cmo-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-cmo-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-cmo.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-cmo.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-condmov.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-condmov.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-fmemidx-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-fmemidx-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-fmemidx-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-fmemidx.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-fmemidx.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mac.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mac.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-memidx-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-memidx-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-memidx-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-memidx.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-memidx.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mempair-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mempair-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mempair-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mempair.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-mempair.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-sync-fail.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-sync-fail.l
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-sync-fail.s
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-sync.d
>> >  create mode 100644 gas/testsuite/gas/riscv/x-thead-sync.s
>> >
>> > --
>> > 2.37.2
>> >
>>
>


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