1 files changed, 77 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Atomics/compareExchange/good-views.js b/js/src/tests/test262/built-ins/Atomics/compareExchange/good-views.js
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+++ b/js/src/tests/test262/built-ins/Atomics/compareExchange/good-views.js
@@ -0,0 +1,77 @@
+// |reftest| skip-if(!this.hasOwnProperty('Atomics')||!this.hasOwnProperty('SharedArrayBuffer')||(this.hasOwnProperty('getBuildConfiguration')&&getBuildConfiguration('arm64-simulator'))) -- Atomics,SharedArrayBuffer is not enabled unconditionally, ARM64 Simulator cannot emulate atomics
+// Copyright (C) 2017 Mozilla Corporation.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-atomics.compareexchange
+description: Test Atomics.compareExchange on arrays that allow atomic operations.
+includes: [testAtomics.js, testTypedArray.js]
+features: [ArrayBuffer, Atomics, DataView, SharedArrayBuffer, Symbol, TypedArray]
+---*/
+
+const sab = new SharedArrayBuffer(1024);
+const ab = new ArrayBuffer(16);
+const views = nonClampedIntArrayConstructors.slice();
+
+testWithTypedArrayConstructors(function(TA) {
+  // Make it interesting - use non-zero byteOffsets and non-zero indexes.
+
+  const view = new TA(sab, 32, 20);
+  const control = new TA(ab, 0, 2);
+
+  // Performs the exchange
+  view[8] = 0;
+  assert.sameValue(
+    Atomics.compareExchange(view, 8, 0, 10),
+    0,
+    'Atomics.compareExchange(view, 8, 0, 10) returns 0'
+  );
+  assert.sameValue(view[8], 10, 'The value of view[8] is 10');
+
+  view[8] = 0;
+  assert.sameValue(Atomics.compareExchange(view, 8, 1, 10), 0,
+    'Atomics.compareExchange(view, 8, 1, 10) returns 0');
+  assert.sameValue(view[8], 0, 'The value of view[8] is 0');
+
+  view[8] = 0;
+  assert.sameValue(Atomics.compareExchange(view, 8, 0, -5), 0,
+    'Atomics.compareExchange(view, 8, 0, -5) returns 0');
+  control[0] = -5;
+  assert.sameValue(view[8], control[0], 'The value of view[8] equals the value of `control[0]` (-5)');
+
+
+  view[3] = -5;
+  control[0] = -5;
+  assert.sameValue(Atomics.compareExchange(view, 3, -5, 0), control[0],
+    'Atomics.compareExchange(view, 3, -5, 0) returns the value of `control[0]` (-5)');
+  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+
+
+  control[0] = 12345;
+  view[3] = 12345;
+  assert.sameValue(Atomics.compareExchange(view, 3, 12345, 0), control[0],
+    'Atomics.compareExchange(view, 3, 12345, 0) returns the value of `control[0]` (12345)');
+  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+
+  control[0] = 123456789;
+  view[3] = 123456789;
+  assert.sameValue(Atomics.compareExchange(view, 3, 123456789, 0), control[0],
+    'Atomics.compareExchange(view, 3, 123456789, 0) returns the value of `control[0]` (123456789)');
+  assert.sameValue(view[3], 0, 'The value of view[3] is 0');
+
+  // In-bounds boundary cases for indexing
+  testWithAtomicsInBoundsIndices(function(IdxGen) {
+    let Idx = IdxGen(view);
+    view.fill(0);
+    // Atomics.store() computes an index from Idx in the same way as other
+    // Atomics operations, not quite like view[Idx].
+    Atomics.store(view, Idx, 37);
+    assert.sameValue(
+      Atomics.compareExchange(view, Idx, 37, 0),
+      37,
+      'Atomics.compareExchange(view, Idx, 37, 0) returns 37'
+    );
+  });
+}, views);
+
+reportCompare(0, 0);