docs(simd): correct stale '5 of 30 types' claim — PR #146 shipped full parity

The note in src/simd.rs (and the matching paragraph in
scripts/miri-tests.sh) was written against an early draft of
simd_nightly that defined 5 types: F32x16, F64x8, U8x64, U32x16,
F32Mask16. PR #146 expanded the polyfill to full parity:

  simd_nightly: 24 types
  simd_avx512 + simd_avx2: 24 types

(F32x8/16, F64x4/8, BF16x8/16, F16x16, I8x32/64, I16x16/32, I32x16,
I64x8, U8x32/64, U16x32, U32x8/16, U64x4/8, plus the F32/F64 mask
types — `grep '^pub struct ' src/simd_nightly/*.rs | grep -v
_original_draft | sort -u | wc -l` confirms.)

`src/simd_nightly/_original_draft.rs` survives on disk as the early
5-type sketch but is NOT in `simd_nightly/mod.rs` — dead-file, not
compiled. Separate janitorial concern (file deletion); the comment
correction lands here.

The architectural follow-up for Miri-clean `hpc::*` coverage is
NOT polyfill expansion — that work is done. It's a cfg(miri) switch
in `src/simd.rs` that re-exports from `simd_nightly` instead of
`simd_avx*` when Miri is the target. Comment rewritten to say so.

Author: claude

scripts/miri-tests.sh

@@ -48,22 +48,14 @@ export RUSTFLAGS="-Zrandomize-layout"
 # Miri target doesn't enable AVX/AVX2/AVX-512/NEON target features.
 #
 # The `nightly-simd` feature ships a parallel module `crate::simd_nightly`
-# (the 30-type `core::simd` polyfill) which IS Miri-checkable, but the
-# default `crate::simd::*` dispatch is NOT routed through it — that's a
-# deliberate decision noted in `src/simd.rs:212`. Consumer modules that
-# import `crate::simd::F32x16` (most of `hpc::*`) therefore go through
-# intrinsics and abort under Miri.
-#
-# Until the polyfill expands to full type-parity (5/30 today) AND
-# `crate::simd::*` gains a `cfg(miri)` dispatch through it, we constrain
-# this sweep to:
-#   * `simd_nightly::tests::*`  — the polyfill itself, full coverage.
-#   * `hpc::byte_scan::*`       — already exercises scalar fallback paths
-#                                  through `simd_caps()` cfg(miri) bypass.
-#   * everything else ndarray ships that does NOT pull `_mm*` intrinsics.
-#
-# `--no-fail-fast` so a single regression doesn't mask the rest. CI
-# nextest profile `default-miri` already configures isolated retry-on-flake.
+# (the 24-type `core::simd` polyfill, at full parity with the 24 types
+# defined across `simd_avx2.rs` + `simd_avx512.rs` — landed in PR #146)
+# which IS Miri-checkable. But the default `crate::simd::*` dispatch is
+# NOT routed through it; consumer modules that import `crate::simd::F32x16`
+# (most of `hpc::*` + the `simd::tests::*` suite) go through intrinsics.
+# The polyfill is no longer the bottleneck — the missing piece is a
+# `cfg(miri)` switch in `src/simd.rs` that re-exports from `simd_nightly`
+# instead of `simd_avx*` under Miri.
 cargo +nightly miri nextest run -v \
     --no-fail-fast \
     -p ndarray -p ndarray-rand \

src/simd.rs

@@ -205,12 +205,19 @@ pub const PREFERRED_I16_LANES: usize = 16;
 
 // Note on the `nightly-simd` feature: it adds the `crate::simd_nightly`
 // module (a portable-simd backend wrapping `core::simd`) but does NOT
-// replace the intrinsics dispatch below. Full type-parity coverage
-// would require the nightly module to define ~30 types; the current
-// draft covers 5 (F32x16, F64x8, U8x64, U32x16, F32Mask16). Consumers
-// who want miri-runnable SIMD code import from `simd_nightly`
-// explicitly (e.g. `use ndarray::simd_nightly::F32x16`). The main
-// polyfill via `crate::simd::F32x16` continues to use intrinsics.
+// replace the intrinsics dispatch below. The polyfill ships full
+// type-parity with production (PR #146): 24 types covering F32x8/16,
+// F64x4/8, BF16x8/16, F16x16, I8x32/64, I16x16/32, I32x16, I64x8,
+// U8x32/64, U16x32, U32x8/16, U64x4/8, plus the F32/F64 mask types —
+// matches the 24 types defined in `simd_avx2.rs` + `simd_avx512.rs`.
+// Consumers who want miri-runnable SIMD code import from `simd_nightly`
+// explicitly today (e.g. `use ndarray::simd_nightly::F32x16`).
+//
+// The remaining work for Miri-clean coverage of `hpc::*` is wiring this
+// file's `pub use crate::simd_{avx512,avx2,neon}::*` re-exports to
+// route through `simd_nightly` under `cfg(miri)`. Once that lands,
+// every `use crate::simd::F32x16` call site becomes miri-checkable
+// without source changes. The polyfill itself is no longer the bottleneck.
 
 #[cfg(all(target_arch = "x86_64", target_feature = "avx512f"))]
 pub use crate::simd_avx512::{