1 files changed, 42 insertions, 0 deletions
diff --git a/toolkit/components/translations/content/simd-detect-worker.js b/toolkit/components/translations/content/simd-detect-worker.js
new file mode 100644
index 0000000000..35efce5e25
--- /dev/null
+++ b/toolkit/components/translations/content/simd-detect-worker.js
@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+let isSimdSupported = false;
+
+/**
+ * WebAssembly counts as unsafe eval in privileged contexts, so we have to execute this
+ * code in a ChromeWorker. The code feature detects SIMD support. The comment above
+ * the binary code is the .wat version of the .wasm binary.
+ */
+
+try {
+  new WebAssembly.Module(
+    new Uint8Array(
+      // ```
+      // ;; Detect SIMD support.
+      // ;; Compile by running: wat2wasm --enable-all simd-detect.wat
+      //
+      // (module
+      //   (func (result v128)
+      //     i32.const 0
+      //     i8x16.splat
+      //     i8x16.popcnt
+      //   )
+      // )
+      // ```
+
+      // prettier-ignore
+      [
+        0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x05, 0x01, 0x60, 0x00,
+        0x01, 0x7b, 0x03, 0x02, 0x01, 0x00, 0x0a, 0x0a, 0x01, 0x08, 0x00, 0x41, 0x00,
+        0xfd, 0x0f, 0xfd, 0x62, 0x0b
+      ]
+    )
+  );
+  isSimdSupported = true;
+} catch (error) {
+  console.error(`Translations: SIMD not supported`, error);
+}
+
+postMessage({ isSimdSupported });