Skip to content

docs: wasm32 SIMD is a shipped compile-time arm, not a future runtime tier #284

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
AdaWorldAPI merged 1 commit into from
Aug 27, 2026
+11 −1
Merged

docs: wasm32 SIMD is a shipped compile-time arm, not a future runtime tier #284

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 11 additions & 1 deletion src/hpc/simd_dispatch.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,17 @@
//! | 3 | SSE2 | 128-bit | `caps.sse2` (always true on x86_64) |
//! | 4 | Scalar | 1 lane | fallback |
//!
//! On wasm32 (future): tier would be WASM SIMD (128-bit, `+simd128`).
//! **wasm32 is not a tier here, by construction.** The table above is
//! *runtime* dispatch over `simd_caps()`; wasm SIMD is selected at COMPILE
//! time instead — `cfg(all(target_arch = "wasm32", target_feature =
//! "simd128"))` in `crate::simd` re-exports the native 128-bit `v128`
//! types from `crate::simd_wasm::wasm32_simd`, with a full scalar fallback
//! when `simd128` is absent. There is no wasm runtime feature probe to
//! dispatch on, so nothing is added to `SimdTier`.
//!
//! That arm is shipped and CI-verified, not future work: the
//! `wasm-simd/parity-node` job builds the real `+simd128` types and runs a
//! lane-vs-scalar selfcheck under node (`scripts/wasm-parity.sh`).

use super::simd_caps::simd_caps;
use std::sync::LazyLock;
Expand Down
Loading