# NL.net proposal


## Project name

OpenPOWER ISA RFCs

## Website / wiki 

<https://libre-soc.org/nlnet_2022_opf_isa_wg>

Please be short and to the point in your answers; focus primarily on
the what and how, not so much on the why. Add longer descriptions as
attachments (see below). If English isn't your first language, don't
worry - our reviewers don't care about spelling errors, only about
great ideas. We apologise for the inconvenience of having to submit in
English. On the up side, you can be as technical as you need to be (but
you don't have to). Do stay concrete. Use plain text in your reply only,
if you need any HTML to make your point please include this as attachment.

## Abstract: Can you explain the whole project and its expected outcome(s).

The current NLnet funding to date has allowed Libre-SOC to develop
one of the most powerful Scalable Vector ISAs in the world.
The 25-year-old Power ISA, developed and curated by IBM, was
transferred to the OpenPOWER Foundation, and is the basis of
Simple-V, the Draft Scalable Vector Extension.

Simple-V *needs* to be submitted to the OPF ISA Working Group,
for formal discussion and inclusion. Given that it is 380
pages we expect this to be done carefully and incrementally.
https://ftp.libre-soc.org/simple_v_spec.pdf

However the
process of submitting Requests For Change, at the time of writing,
still has not been publicly announced and opened up. We expect it
to be very soon, but obviously could not begin any RFC Submission as
part of the earlier NLnet funding.

We will also become informed very shortly of the procedures but anticipate
it to include development and submission of Compliance Test Suites
(already partly covered by Simple-V unit tests, kindly funded by NLnet)
as well as ongoing work on the Simulator.

# Have you been involved with projects or organisations relevant to this project before? And if so, can you tell us a bit about your contributions?

A lot! a full list is maintained here <https://libre-soc.org/nlnet_proposals/>
and includes the world's first FOSSHW IEEE754 Formal Correctness Proofs for fadd, fsub, and fma, with support for FP Formal Proofs added to symbiyosis;
the world's first in-place Discrete Cosine Transform algorithm;
Significant improvements to Europe's only silicon-proven FOSSHW VLSI toolchain (coriolis2, by LIP6 Labs) to do an 800,000 transistor fully automated RTL2GDSII
tape-out; the side-benefits alone are enormous.

# Requested Amount    

EUR 100,000.

# Explain what the requested budget will be used for? 

* ongoing communication with the OpenPOWER Foundation ISA Working Group
* preparation of a large number of RFCs (380 pages total so far) through
  the External RFC Process
* for each RFC accepted, work needs to be done with IBM to submit Power ISA Spec
  changes
* for each RFC accepted, a Compliance Test Suite must be written
* for each Compliance Test Suite written the results must be
  confirmed correct by inspection (hence the Simulator) which has
  as we already discovered been quite a lot of work
* Along the way we aim to continue developing the "Test API" which
  allows running thousands of unit tests on multiple systems and
  cross-checking the results.  Currently we have Simulator, some
  "Expected Results", and the Libre-SOC HDL as well as qemu.
  We aim to add cavatools, gem5, Microwatt and stand-alone binary
  auto-generation for running on IBM POWER9 as well as Libre-SOC
  and Microwatt FPGAs.

# Compare your own project with existing or historical efforts.

We are developing a Cray-style Scalable Vector ISA Extension for
the Supercomputing-class Power ISA.  Similar historic ISAs include
Cray YMP1, ETA-19, Cyber CDC 205. More recent is the NEC SX Aurora.
They are all proprietary systems: Libre-SOC's efforts are entirely
FOSSHW.

Open Scalable Vector ISAs include MRISC32/64 (in early development) and
RISC-V RVV. Advocates of RISC-V have been discovering to their dismay
that RVV and RISC-V has fundamental issues that cannot be fixed.
Additionally, submission of ISA modifications requires RISCV Foundation
Membership which puts us under impossible conflict of interest with
Full Transparency Conditions not only with NLnet but also with
EU Auditing Requirements.  By direct contrast OPF External RFC Submission
does not require Secrecy.

## What are significant technical challenges you expect to solve during the project, if any?



## Describe the ecosystem of the project, and how you will engage with relevant actors and promote the outcomes?


# Extra info to be submitted

* TODO URLs etc