Index: test/webkit/dfg-integer-optimization.js |
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/dfg-integer-optimization.js |
similarity index 60% |
copy from test/webkit/concat-while-having-a-bad-time.js |
copy to test/webkit/dfg-integer-optimization.js |
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..31ec8fce4f0e5fb9a1346b356a6666d63e21138e 100644 |
--- a/test/webkit/concat-while-having-a-bad-time.js |
+++ b/test/webkit/dfg-integer-optimization.js |
@@ -22,10 +22,25 @@ |
// 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)) |
+} |