feat: add wasm32 arch, implement check

.github/workflows/ci.yml

@@ -20,8 +20,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        target: [aarch64-unknown-linux-gnu, i686-unknown-linux-gnu, x86_64-unknown-linux-gnu]
+        target:
+          - aarch64-unknown-linux-gnu
+          - i686-unknown-linux-gnu
+          - x86_64-unknown-linux-gnu
+          - wasm32-wasip1
         rust: [nightly, stable, 1.64]
+        exclude:
+          - target: wasm32-wasip1
+            rust: 1.64
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@v4

src/arch/mod.rs

@@ -13,6 +13,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_arch = "aarch64")] {
         pub(crate) mod aarch64;
         pub(crate) use aarch64 as imp;
+    } else if #[cfg(target_arch = "wasm32")] {
+        pub(crate) mod wasm32;
+        pub(crate) use wasm32 as imp;
     } else {
         pub(crate) use generic as imp;
     }

src/arch/wasm32.rs

@@ -0,0 +1,40 @@
+use super::generic;
+use core::arch::wasm32::*;
+
+pub(crate) const USE_CHECK_FN: bool = false;
+
+pub(crate) use generic::{decode_checked, decode_unchecked, encode};
+
+#[inline(always)]
+fn is_available() -> bool {
+    cfg!(target_feature = "simd128")
+}
+
+#[inline]
+pub(crate) fn check(input: &[u8]) -> bool {
+    if !is_available() {
+        return generic::check(input);
+    }
+    unsafe { check_simd128(input) }
+}
+
+#[target_feature(enable = "simd128")]
+unsafe fn check_simd128(input: &[u8]) -> bool {
+    generic::check_unaligned_chunks(input, |chunk: v128| {
+        let ge0 = u8x16_ge(chunk, u8x16_splat(b'0'));
+        let le9 = u8x16_le(chunk, u8x16_splat(b'9'));
+        let valid_digit = v128_and(ge0, le9);
+
+        let geua = u8x16_ge(chunk, u8x16_splat(b'A'));
+        let leuf = u8x16_le(chunk, u8x16_splat(b'F'));
+        let valid_upper = v128_and(geua, leuf);
+
+        let gela = u8x16_ge(chunk, u8x16_splat(b'a'));
+        let lelf = u8x16_le(chunk, u8x16_splat(b'f'));
+        let valid_lower = v128_and(gela, lelf);
+
+        let valid_letter = v128_or(valid_lower, valid_upper);
+        let valid = v128_or(valid_digit, valid_letter);
+        u8x16_all_true(valid)
+    })
+}