Wasmtime GitHub notifications bot (Feb 21 2023 at 16:12): Wasmtime GitHub notifications bot (Feb 21 2023 at 16:12):afonso360 opened PR #5847 from riscv-bitmanip-flags to main:
This PR clarifies our bit manipulation set of ISA flags.
It seems that our current "B" extension is the full set of instructions defined in the Bit-Manipulation extension (pdf). However we should be querying each extension individually since some processors may not implement all of them.
Additionally it may cause confusion with the currently reserved B extension defined in Chapter 19 of the ISA (pdf). These are unrelated and there is no connection between "B" and the various extensions defined in the Bit-Manipulation spec.
As an example, the SiFive U74 implements only a subset of these (Zbb, Zba) so it wouldn't qualify for most of these optimizations previously, despite most of them only needing Zbb.
Wasmtime GitHub notifications bot (Feb 21 2023 at 16:12):afonso360 edited PR #5847 from riscv-bitmanip-flags to main:
This PR clarifies our bit manipulation set of ISA flags.
It seems that our current "B" extension is the full set of instructions defined in the Bit-Manipulation spec (pdf). However we should be querying each extension individually since some processors may not implement all of them.
Additionally it may cause confusion with the currently reserved B extension defined in Chapter 19 of the ISA (pdf). These are unrelated and there is no connection between "B" and the various extensions defined in the Bit-Manipulation spec.
As an example, the SiFive U74 implements only a subset of these (Zbb, Zba) so it wouldn't qualify for most of these optimizations previously, despite most of them only needing Zbb.
Wasmtime GitHub notifications bot (Feb 21 2023 at 21:12):jameysharp submitted PR review.
Wasmtime GitHub notifications bot (Feb 21 2023 at 22:56):afonso360 merged PR #5847.
Last updated: Dec 23 2024 at 12:05 UTC