In D149751#4316073, @MaskRay wrote:

This relaxation enables use of weak undefined symbols in programms written with medany code model in mind if code section happens to be placed far from zero address(>2GiB).

I think the motivation is not right. For such weak references, the compiler should generate GOT-generating relocations, not relying on linker relaxation (which is an optional feature) for correctness. https://maskray.me/blog/2021-04-25-weak-symbol

https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/201 "Not doing so is deprecated and a future version of this specification will require using the GOT, not just advise."

Rebased

It is very similar to this: https://reviews.llvm.org/D132650

• Added autogenerated checks.
• Removed notes completely.

I found a bug in RISCV backend. Reproduction: https://godbolt.org/z/qscGYbWvr
This patch fixes it.

Rebased and resolved merge conflicts.

Thanks! I didn't know that.
I will rebase and ask for merge.

All fixed now. Ping for review.

rebased

Fixed formatting issues.

I want to ping on this again

ping

So, after more running more spec tests in different modes (train and ref) on different RISCV boards (SiFive and THead) I got mixed results on performance. Performance increase on number on tests was insignificant while on other there was a slight decrease. On average performance declined by 0.5%. On the other hand, size reduction can be seen uniformly among all tests. On average it is 20 less bytes or 0.04% of size reduction. I think these amounts can't justify the performance cost.
Considering that some performance reductions are platform specific (like the one I mentioned in previous comment) and rely on internal architecture features, it is not seem possible to come up with general solution here. And more specialized ones will require more time and effort. And possible 0.04% code size reduction just not worth it.
What do you think?

• Removed Operand suffixes
• Added whitespaces between definitons

Sorry for long silence.
I've benchmarked SPEC with llvm-test-suite on Alibaba THead machine and found out that there is slight performance downgrade with this substitution. I've isolated one case:

Fixed missing commit