require 'simd128' on 'wasm32'

.github/workflows/ci.yml

@@ -89,7 +89,7 @@ jobs:
           target: s390x-unknown-linux-gnu
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -138,7 +138,7 @@ jobs:
       WASMTIME_VERSION: 15.0.1
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -152,7 +152,40 @@ jobs:
         curl -LO https://github.com/bytecodealliance/wasmtime/releases/download/v$WASMTIME_VERSION/wasmtime-v$WASMTIME_VERSION-x86_64-linux.tar.xz
         tar xvf wasmtime-v$WASMTIME_VERSION-x86_64-linux.tar.xz
         echo `pwd`/wasmtime-v$WASMTIME_VERSION-x86_64-linux >> $GITHUB_PATH
-        echo "CARGO_TARGET_WASM32_WASI_RUNNER=wasmtime run --wasm-features simd --" >> $GITHUB_ENV
+        echo "CARGO_TARGET_WASM32_WASI_RUNNER=wasmtime run --wasm simd --" >> $GITHUB_ENV
+    - name: Basic build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose
+    - name: Run with only 'alloc' enabled
+      run: cargo test --verbose --no-default-features --features alloc
+    - name: Run tests without any features enabled (core-only)
+      run: cargo test --verbose --no-default-features
+
+  # Setup and run tests on the wasm32-wasi target via wasmtime, but without
+  # simd128 enabled.
+  wasm-no-simd128:
+    runs-on: ubuntu-latest
+    env:
+      # The version of wasmtime to download and install.
+      WASMTIME_VERSION: 15.0.1
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+    - name: Install Rust
+      uses: dtolnay/rust-toolchain@master
+      with:
+        toolchain: stable
+    - name: Add wasm32-wasi target
+      run: rustup target add wasm32-wasi
+    - name: Download and install Wasmtime
+      run: |
+        echo "CARGO_BUILD_TARGET=wasm32-wasi" >> $GITHUB_ENV
+        echo "RUSTFLAGS=-Ctarget-feature=-simd128" >> $GITHUB_ENV
+        curl -LO https://github.com/bytecodealliance/wasmtime/releases/download/v$WASMTIME_VERSION/wasmtime-v$WASMTIME_VERSION-x86_64-linux.tar.xz
+        tar xvf wasmtime-v$WASMTIME_VERSION-x86_64-linux.tar.xz
+        echo `pwd`/wasmtime-v$WASMTIME_VERSION-x86_64-linux >> $GITHUB_PATH
+        echo "CARGO_TARGET_WASM32_WASI_RUNNER=wasmtime run --" >> $GITHUB_ENV
     - name: Basic build
       run: cargo build --verbose
     - name: Run tests
@@ -168,7 +201,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -197,7 +230,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -214,7 +247,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -232,7 +265,7 @@ jobs:
       WASMTIME_VERSION: 15.0.1
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:
@@ -260,7 +293,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master
       with:

src/arch/mod.rs

@@ -10,7 +10,7 @@ pub(crate) mod generic;
 
 #[cfg(target_arch = "aarch64")]
 pub mod aarch64;
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
 pub mod wasm32;
 #[cfg(target_arch = "x86_64")]
 pub mod x86_64;

src/arch/wasm32/memchr.rs

@@ -8,27 +8,14 @@ available for `wasm32` targets.)
 
 macro_rules! defraw {
     ($ty:ident, $find:ident, $start:ident, $end:ident, $($needles:ident),+) => {{
-        #[cfg(target_feature = "simd128")]
-        {
-            use crate::arch::wasm32::simd128::memchr::$ty;
+        use crate::arch::wasm32::simd128::memchr::$ty;
 
-            debug!("chose simd128 for {}", stringify!($ty));
-            debug_assert!($ty::is_available());
-            // SAFETY: We know that wasm memchr is always available whenever
-            // code is compiled for `wasm32` with the `simd128` target feature
-            // enabled.
-            $ty::new_unchecked($($needles),+).$find($start, $end)
-        }
-        #[cfg(not(target_feature = "simd128"))]
-        {
-            use crate::arch::all::memchr::$ty;
-
-            debug!(
-                "no simd128 feature available, using fallback for {}",
-                stringify!($ty),
-            );
-            $ty::new($($needles),+).$find($start, $end)
-        }
+        debug!("chose simd128 for {}", stringify!($ty));
+        debug_assert!($ty::is_available());
+        // SAFETY: We know that wasm memchr is always available whenever
+        // code is compiled for `wasm32` with the `simd128` target feature
+        // enabled.
+        $ty::new_unchecked($($needles),+).$find($start, $end)
     }}
 }
 

src/arch/wasm32/simd128/packedpair.rs

@@ -81,14 +81,13 @@ impl Finder {
     /// true then it will always return true.
     #[inline]
     pub fn is_available() -> bool {
-        #[cfg(target_feature = "simd128")]
-        {
-            true
-        }
-        #[cfg(not(target_feature = "simd128"))]
-        {
-            false
-        }
+        // We used to gate on `cfg(target_feature = "simd128")` here, but
+        // we've since required the feature to be enabled at compile time to
+        // even include this module at all. Therefore, it is always enabled
+        // in this context. See the linked issue for why this was changed.
+        //
+        // Ref: https://github.com/BurntSushi/memchr/issues/144
+        true
     }
 
     /// Execute a search using wasm32 v128 vectors and routines.

src/lib.rs

@@ -177,7 +177,7 @@ Originally, this crate was literally just a safe wrapper function around the
 #![cfg_attr(
     not(any(
         all(target_arch = "x86_64", target_feature = "sse2"),
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64",
     )),
     allow(dead_code)

src/memchr.rs

@@ -514,7 +514,7 @@ unsafe fn memchr_raw(
         // nor SSE2 (unusual) are available.
         crate::arch::x86_64::memchr::memchr_raw(needle, start, end)
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memchr_raw(needle, start, end)
     }
@@ -524,7 +524,7 @@ unsafe fn memchr_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -547,7 +547,7 @@ unsafe fn memrchr_raw(
     {
         crate::arch::x86_64::memchr::memrchr_raw(needle, start, end)
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memrchr_raw(needle, start, end)
     }
@@ -557,7 +557,7 @@ unsafe fn memrchr_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -581,7 +581,7 @@ unsafe fn memchr2_raw(
     {
         crate::arch::x86_64::memchr::memchr2_raw(needle1, needle2, start, end)
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memchr2_raw(needle1, needle2, start, end)
     }
@@ -591,7 +591,7 @@ unsafe fn memchr2_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -616,7 +616,7 @@ unsafe fn memrchr2_raw(
     {
         crate::arch::x86_64::memchr::memrchr2_raw(needle1, needle2, start, end)
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memrchr2_raw(needle1, needle2, start, end)
     }
@@ -628,7 +628,7 @@ unsafe fn memrchr2_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -656,7 +656,7 @@ unsafe fn memchr3_raw(
             needle1, needle2, needle3, start, end,
         )
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memchr3_raw(
             needle1, needle2, needle3, start, end,
@@ -670,7 +670,7 @@ unsafe fn memchr3_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -698,7 +698,7 @@ unsafe fn memrchr3_raw(
             needle1, needle2, needle3, start, end,
         )
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::memrchr3_raw(
             needle1, needle2, needle3, start, end,
@@ -712,7 +712,7 @@ unsafe fn memrchr3_raw(
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {
@@ -732,7 +732,7 @@ unsafe fn count_raw(needle: u8, start: *const u8, end: *const u8) -> usize {
     {
         crate::arch::x86_64::memchr::count_raw(needle, start, end)
     }
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     {
         crate::arch::wasm32::memchr::count_raw(needle, start, end)
     }
@@ -742,7 +742,7 @@ unsafe fn count_raw(needle: u8, start: *const u8, end: *const u8) -> usize {
     }
     #[cfg(not(any(
         target_arch = "x86_64",
-        target_arch = "wasm32",
+        all(target_arch = "wasm32", target_feature = "simd128"),
         target_arch = "aarch64"
     )))]
     {

src/memmem/searcher.rs

@@ -5,7 +5,7 @@ use crate::arch::all::{
 
 #[cfg(target_arch = "aarch64")]
 use crate::arch::aarch64::neon::packedpair as neon;
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
 use crate::arch::wasm32::simd128::packedpair as simd128;
 #[cfg(all(target_arch = "x86_64", target_feature = "sse2"))]
 use crate::arch::x86_64::{
@@ -109,7 +109,7 @@ impl Searcher {
                 Searcher::twoway(needle, rabinkarp, prestrat)
             }
         }
-        #[cfg(target_arch = "wasm32")]
+        #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
         {
             if let Some(pp) = simd128::Finder::with_pair(needle, pair) {
                 if do_packed_search(needle) {
@@ -151,7 +151,7 @@ impl Searcher {
         }
         #[cfg(not(any(
             all(target_arch = "x86_64", target_feature = "sse2"),
-            target_arch = "wasm32",
+            all(target_arch = "wasm32", target_feature = "simd128"),
             target_arch = "aarch64"
         )))]
         {
@@ -251,7 +251,7 @@ union SearcherKind {
     sse2: crate::arch::x86_64::sse2::packedpair::Finder,
     #[cfg(all(target_arch = "x86_64", target_feature = "sse2"))]
     avx2: crate::arch::x86_64::avx2::packedpair::Finder,
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     simd128: crate::arch::wasm32::simd128::packedpair::Finder,
     #[cfg(target_arch = "aarch64")]
     neon: crate::arch::aarch64::neon::packedpair::Finder,
@@ -400,7 +400,7 @@ unsafe fn searcher_kind_avx2(
 /// # Safety
 ///
 /// Callers must ensure that the `searcher.kind.simd128` union field is set.
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
 unsafe fn searcher_kind_simd128(
     searcher: &Searcher,
     _prestate: &mut PrefilterState,
@@ -671,7 +671,7 @@ impl Prefilter {
     }
 
     /// Return a prefilter using a wasm32 simd128 vector algorithm.
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     #[inline]
     fn simd128(finder: simd128::Finder, needle: &[u8]) -> Prefilter {
         trace!("building wasm32 simd128 prefilter");
@@ -761,7 +761,7 @@ union PrefilterKind {
     sse2: crate::arch::x86_64::sse2::packedpair::Finder,
     #[cfg(all(target_arch = "x86_64", target_feature = "sse2"))]
     avx2: crate::arch::x86_64::avx2::packedpair::Finder,
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
     simd128: crate::arch::wasm32::simd128::packedpair::Finder,
     #[cfg(target_arch = "aarch64")]
     neon: crate::arch::aarch64::neon::packedpair::Finder,
@@ -833,7 +833,7 @@ unsafe fn prefilter_kind_avx2(
 /// # Safety
 ///
 /// Callers must ensure that the `strat.kind.simd128` union field is set.
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
 unsafe fn prefilter_kind_simd128(
     strat: &Prefilter,
     haystack: &[u8],

src/vector.rs

@@ -464,7 +464,7 @@ mod aarch64neon {
     }
 }
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", target_feature = "simd128"))]
 mod wasm_simd128 {
     use core::arch::wasm32::*;