str short, 128-bit SIMD, AVX512VL split

.github/workflows/artifact.yaml

@@ -79,6 +79,9 @@ jobs:
       options: --user 0
     steps:
 
+    - name: cpuinfo
+      run: cat /proc/cpuinfo
+
     - uses: actions/checkout@v4
 
     - name: Build environment

.github/workflows/debug.yaml

@@ -11,6 +11,7 @@ jobs:
           { rust: "1.72", features: "" },
           { rust: "1.72", features: "--features=yyjson" },
           { rust: "nightly-2024-04-30", features: "--features=yyjson,unstable-simd"},
+          { rust: "nightly-2024-04-30", features: "--features=avx512,yyjson,unstable-simd"},
         ]
         python: [
           { version: '3.13' },
@@ -26,6 +27,9 @@ jobs:
     steps:
     - run: curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain ${{ matrix.profile.rust }} --profile minimal -y
 
+    - name: cpuinfo
+      run: cat /proc/cpuinfo
+
     - uses: actions/setup-python@v5
       with:
         allow-prereleases: true

Cargo.toml

@@ -35,6 +35,9 @@ default = []
 # Use SIMD intrinsics. This requires Rust on the nightly channel.
 unstable-simd = []
 
+# Include runtime-detected functions that use AVX512VL. Requires unstable-simd and amd64.
+avx512 = []
+
 no-panic = [
     "itoa/no-panic",
     "ryu/no-panic",

src/lib.rs

@@ -1,5 +1,13 @@
 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+#![cfg_attr(
+    all(target_arch = "x86_64", feature = "avx512"),
+    feature(avx512_target_feature)
+)]
+#![cfg_attr(
+    all(target_arch = "x86_64", feature = "avx512"),
+    feature(stdarch_x86_avx512)
+)]
 #![cfg_attr(feature = "intrinsics", feature(core_intrinsics))]
 #![cfg_attr(feature = "optimize", feature(optimize_attribute))]
 #![cfg_attr(feature = "strict_provenance", feature(strict_provenance))]