[llvm-dev] [RFC] AAP Backend

[Ed Jones via llvm-dev]

Hi all,

We wish to submit our latest AAP implementation as an experimental
backend into LLVM. We need community feedback and reviewers for patches
which we will submit soon.

AAP was designed in early 2015 and aims to advance compiler development
for small deeply embedded Harvard architectures, which are widely used
commercially. AAP is freely available as an open source softcore for use
in FPGA designs.

AAP has wide exposure: at ORCONF16 at CERN, at FOSDEM and at BCS and
OSHUG meetings. It is also of commercial interest, because of the
potential benefits of providing upstream LLVM support for features found
in small embedded processors.

Currently there is a complete Clang and LLVM toolchain including gdb, ld
and binutils, as well as two simulator implementations. The toolchain is
passing all LLVM regression tests and a decent proportion of GCC
regression tests. We are also working on a GCC port to allow comparison
between compilers, which should be beneficial to both projects.

We believe the code base is sufficiently mature that it is appropriate
for inclusion. Currently, the full source for AAP can be found on Github:
https://github.com/embecosm

Details about the ISA, and the hardware implementation can be found on
our website:
http://www.embecosm.com/resources/appnotes/#EAN13
http://www.embecosm.com/resources/appnotes/#EAN14

We are also planning to talk about AAP at the LLVM Cauldron in Hebden
Bridge. We look forward to discussing our work on AAP with those who are
attending.

Thank you,
Ed Jones