rust/library/std_detect/src
bors 00f49d2204 Auto merge of #145948 - a4lg:riscv-stabilize-target-features-v2, r=Amanieu
Stabilize 29 RISC-V target features (`riscv_ratified_v2`)

This commit stabilizes RISC-V target features with following constraints:

*   Describes a ratified extension.
*   Implemented on Rust 1.88.0 or before.
    Waiting for four+ version cycles seems sufficient.
*   Does not disrupt current rustc's target feature (cf. rust-lang/rust#140570) + ABI (cf. rust-lang/rust#132618) handling.
    It excludes `E` and all floating point-arithmetic extensions.  The `Zfinx` family does not involve floating point registers but not stabilizing for now to avoid possible confusion between the `F` extension family.
*   Not vector-related (floating point and integer).
    While integer vector subsets should not cause any ABI issues (as they don't use ABI-dependent floating point registers), we need to discuss before stabilizing them.
*   Supported by the lowest LLVM version supported by rustc (LLVM 20).

List of target features to be stabilized:

1.  `b`
2.  `za64rs` (no-RT)
3.  `za128rs` (no-RT)
4.  `zaamo`
5.  `zabha`
6.  `zacas`
7.  `zalrsc`
8.  `zama16b` (no-RT)
9.  `zawrs`
10.  `zca`
11. `zcb`
12. `zcmop`
13. `zic64b` (no-RT)
14. `zicbom`
15. `zicbop` (no-RT)
16. `zicboz`
17. `ziccamoa` (no-RT)
18. `ziccif` (no-RT)
19. `zicclsm` (no-RT)
20. `ziccrse` (no-RT)
21. `zicntr`
22. `zicond`
23. `zicsr`
24. `zifencei`
25. `zihintntl`
26. `zihintpause`
27. `zihpm`
28. `zimop`
29. `ztso`

Of which, 20 of them (29 minus 9 "no-RT" target features) support runtime detection through `std::arch::is_riscv_feature_detected!()`.

Corresponding PR for the Reference: rust-lang/reference#1987
2026-01-03 07:26:35 +00:00
..
detect Auto merge of #145948 - a4lg:riscv-stabilize-target-features-v2, r=Amanieu 2026-01-03 07:26:35 +00:00
lib.rs library: Migrate from cfg_if to cfg_select 2025-08-16 05:28:31 -07:00