Luke WrenMar 14

I implemented the (unratified) Zibi extension: https://github.com/riscv/zibi/releases/tag/v0.6

With LLVM it seems to be worth about 1.2% CoreMark/MHz. The improvements are localised to the list benchmark. Unfortunately no GNU toolchain support for this extension yet.

Release Branch with Immediate(Zibi) Extension v0.6 · riscv/zibi

Branch with Immediate (Zibi) Ratification Plan. Contribute to riscv/zibi development by creating an account on GitHub.

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Show threadcamelcdrMar 14

@wren6991 Maybe you can share your results on the mailing list: https://lists.riscv.org/g/sig-scalar-efficiency/topics

BTW, will you implement P once it's ready?

Show threadLuke WrenMar 14
@camelcdr I do plan to implement P once there is a single spec with all of the instructions in it 😅
Show threadLuke Wren
@camelcdr And yeah I was going to try embench too, but a lot of those benchmarks are heavily stdlib-dependent and I'm building my libraries with GCC (just using scripts from riscv-gnu-toolchain with --enable-llvm) so it's going to make things look worse than they are. I guess I can try those SiFive GCC patches for Zibi.
Mar 14 at 12:58pmWeb
Show threadLuke WrenMar 14
@camelcdr Zibi is not looking so hot in embench actually (compilation only, LLVM main):