1 files changed, 22 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/wasm/simd/ion-bug1688262.js b/js/src/jit-test/tests/wasm/simd/ion-bug1688262.js
new file mode 100644
index 0000000000..ebb2f72864
--- /dev/null
+++ b/js/src/jit-test/tests/wasm/simd/ion-bug1688262.js
@@ -0,0 +1,22 @@
+// |jit-test| skip-if: !wasmSimdEnabled()
+
+// Shuffle pattern incorrectly recognized as a rotate due to a missing guard in
+// the optimizer.
+
+let ins = wasmEvalText(`
+  (module
+    (memory (export "mem") 1)
+    (func (export "test")
+      (v128.store (i32.const 0)
+        (i8x16.shuffle 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6
+                       (v128.load (i32.const 16))
+                       (v128.const i32x4 0 0 0 0)))))
+`);
+
+let mem = new Int8Array(ins.exports.mem.buffer);
+let input = [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25];
+let output = [10, 11, 12, 13, 14, 15, 16, 17, 18, 10, 11, 12, 13, 14, 15, 16];
+mem.set(input, 16);
+ins.exports.test();
+let result = Array.from(mem.subarray(0, 16));
+assertDeepEq(output, result);