rust-lang
RISC-V Extensions update including 29 extensions to stabilize
This commit directly corresponds to rust-lang/rust#145948. See that proposal for criteria of 29 new extensions.
Notes (for the Rust reference)
- Updated existing
aandcto imply its subset(s).aequalszalrscandzaamocombined (imply both froma).- The C extension always implies the Zca extension and conditionally implies Zcf and/or Zcd extensions (on RISC-V) but
c(Rust target feature) only implieszcaas bothzcfandzcdare not to be stabilized on this proposal.
- For each extension, linked to the first document containing it with the ratified state. For instance, all extensions present in the RVA23 profiles link to (3) (despite that they are present in (2)) because they were not ratified at the time when (2) is published.
References
- RISC-V Instruction Set Manual (version 20250508) https://github.com/riscv/riscv-isa-manual/tree/20250508
- RISC-V Profiles (version 1.0 - RVA23 profiles were not ratified at the time) https://github.com/riscv/riscv-profiles/tree/v1.0
- RISC-V Profiles (RVA23/RVB23-ratified version) https://github.com/riscv/riscv-profiles/tree/rva23-rvb23-ratified
Possible Consideration
Some platform behavior extensions are hard to make a short, concise summary.
Do we prefer to keep long(er than usual) descriptions? Or, do we just link to the RISC-V Profiles documentation and let it explain?
My Current Position
I prefer the latter if allowed but mdbook design is confirmed not broken so the current approach (long descriptions) is okay for me.
Non-stabilization part is separated as rust-lang/reference#2002.
Submission v2 (zacas is added) of this PR is a superset of rust-lang/reference#2002.
This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.
Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.
Rebased and made some clarification in the commit message (the same as the edited initial comment).