llvm dev - Sep 2019 - RISC-V LLVM sync-up call 26th Sep 2019

For background on these calls, see
<http://lists.llvm.org/pipermail/llvm-dev/2019-September/135087.html>.

Reminder: the purpose is to co-ordinate between active contributors.
If you have support questions etc then it's best to post to llvm-dev.

We have a call each Thursday at 4pm BST, via
<https://meet.google.com/ske-zcog-spp>.

It's a pretty quiet week with various people being away or travelling,
but things to discuss include:

* LLVM 9.0 was released with RISC-V as an official backend - hurray!
Thank you to all contributors
* Target-specific scheduling model - any updates from those working on this?
* Update on buildroot testing - Luis has been picking up this work
again, to provide litmus tests on a large corpus
* Immediate materialisation optimisations:
https://reviews.llvm.org/D68060 - can be a win for code size too
* Splitting SP adjustment https://reviews.llvm.org/D68011 Shiva's
patch seems like a really helpful optimisation and has had a
reasonable amount of review. More eyes always welcome.
* R_RISCV_RELAX_NORVC proposed relocation type - see the psABI
discussion at https://github.com/riscv/riscv-elf-psabi-doc/pull/116
The LLVM community should feed back on this
* Anything else (as usual, always helpful to drop me an email ahead of
time to add to the agenda - but feel free to list things here)

Best,

Alex