Migrated several tests from blink to V8 repository.

test/webkit/dfg-integer-optimization.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 // 1.  Redistributions of source code must retain the above copyright
 //     notice, this list of conditions and the following disclaimer.
 // 2.  Redistributions in binary form must reproduce the above copyright
 //     notice, this list of conditions and the following disclaimer in the
 //     documentation and/or other materials provided with the distribution.
 //
 // THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 // DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 // DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 // ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 description(
-"Tests the behavior of Array.prototype.concat while the array is having a bad time due to one of the elements we are concatenating."
+"This tests that integer addition optimizations in the DFG are not performed too overzealously."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
+function doAdd(a,b) {
+    // The point of this test is to see if the DFG CSE's the second (a + b) against the first, after
+    // optimizing the first to be an integer addition. The first one certainly is an integer addition,
+    // but the second one isn't - it must either be an integer addition with overflow checking, or a
+    // double addition.
+    return {a:((a + b) | 0), b:(a + b)};
+}
 
+for (var i = 0; i < 1000; ++i) {
+    // Create numbers big enough that we'll start seeing doubles only after about 200 invocations.
+    var a = i * 1000 * 1000 * 10;
+    var b = i * 1000 * 1000 * 10 + 1;
+    var result = doAdd(a, b);
 
+    // Use eval() for computing the correct result, to force execution to happen outside the DFG.
+    shouldBe("result.a", "" + eval("((" + a + " + " + b + ") | 0)"))
+    shouldBe("result.b", "" + eval(a + " + " + b))
+}
+