Implement Atomics API

test/mjsunit/asm/atomics-exchange.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-atomics --harmony-sharedarraybuffer
+
+function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM8 = new stdlib.Int8Array(heap);
+  var MEM16 = new stdlib.Int16Array(heap);
+  var MEM32 = new stdlib.Int32Array(heap);
+  var MEMU8 = new stdlib.Uint8Array(heap);
+  var MEMU16 = new stdlib.Uint16Array(heap);
+  var MEMU32 = new stdlib.Uint32Array(heap);
+  var exchange = stdlib.Atomics.exchange;
+  var fround = stdlib.Math.fround;
+
+  function exchangei8(i, x) {
+    i = i | 0;
+    x = x | 0;
+    return exchange(MEM8, i, x)|0;
+  }
+
+  function exchangei16(i, x) {
+    i = i | 0;
+    x = x | 0;
+    return exchange(MEM16, i, x)|0;
+  }
+
+  function exchangei32(i, x) {
+    i = i | 0;
+    x = x | 0;
+    return exchange(MEM32, i, x)|0;
+  }
+
+  function exchangeu8(i, x) {
+    i = i | 0;
+    x = x >>> 0;
+    return exchange(MEMU8, i, x)>>>0;
+  }
+
+  function exchangeu16(i, x) {
+    i = i | 0;
+    x = x >>> 0;
+    return exchange(MEMU16, i, x)>>>0;
+  }
+
+  function exchangeu32(i, x) {
+    i = i | 0;
+    x = x >>> 0;
+    return exchange(MEMU32, i, x)>>>0;
+  }
+
+  return {
+    exchangei8: exchangei8,
+    exchangei16: exchangei16,
+    exchangei32: exchangei32,
+    exchangeu8: exchangeu8,
+    exchangeu16: exchangeu16,
+    exchangeu32: exchangeu32,
+  };
+}
+
+var sab = new SharedArrayBuffer(16);
+var m = Module(this, {}, sab);
+
+function clearArray() {
+  var ui8 = new Uint8Array(sab);
+  for (var i = 0; i < sab.byteLength; ++i) {
+    ui8[i] = 0;
+  }
+}
+
+function testElementType(taConstr, f) {
+  clearArray();
+
+  var ta = new taConstr(sab);
+  var name = Object.prototype.toString.call(ta);
+  ta[0] = 0x7f;
+  assertEquals(0x7f, f(0, 0xf), name);
+  assertEquals(0xf, ta[0]);
+  // out of bounds
+  assertEquals(0, f(-1, 0), name);
+  assertEquals(0, f(ta.length, 0), name);
+}
+
+testElementType(Int8Array, m.exchangei8);
+testElementType(Int16Array, m.exchangei16);
+testElementType(Int32Array, m.exchangei32);
+testElementType(Uint8Array, m.exchangeu8);
+testElementType(Uint16Array, m.exchangeu16);
+testElementType(Uint32Array, m.exchangeu32);