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Unified Diff: test/mjsunit/keyed-load-hole-to-undefined.js

Issue 1100083002: Don't MISS if you read the hole from certain FastHoley arrays. (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: REBASE and fix arm64 compilation. Created 5 years, 8 months ago
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Index: test/mjsunit/keyed-load-hole-to-undefined.js
diff --git a/test/mjsunit/keyed-load-hole-to-undefined.js b/test/mjsunit/keyed-load-hole-to-undefined.js
new file mode 100644
index 0000000000000000000000000000000000000000..e9403b8c5e2233d00e3763cec05fda70fb729e43
--- /dev/null
+++ b/test/mjsunit/keyed-load-hole-to-undefined.js
@@ -0,0 +1,26 @@
+// 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: --allow-natives-syntax
+// Flags: --nostress-opt
+
+// --nostress-opt is specified because the test corrupts the "pristine"
+// array prototype chain by storing an element, and this is tracked
+// per-isolate. A subsequent stress run would send the load generic,
+// and no more deoptimizations of foo would occur.
+
+function foo(a, i) { return a[i]; }
+
+var a = ['one', , 'three'];
+foo(a, 0);
+foo(a, 0);
+foo(a, 0);
+%OptimizeFunctionOnNextCall(foo);
+assertEquals(undefined, foo(a, 1));
+assertOptimized(foo);
+
+// Whereas if we disrupt the prototype chain...
+Array.prototype[1] = 'cow';
+assertEquals('cow', foo(a, 1));
+assertUnoptimized(foo);
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