Do not generate LDummyUse instruction for HCapturedObject

LDummyUse confuses the register allocator (since there is no definition
for the use).

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/222283002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20461 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index d12d47e..1df0f73 100644 (file)
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -509,6 +509,7 @@ bool HValue::CanReplaceWithDummyUses() {
       !(block()->IsReachable() ||
         IsBlockEntry() ||
         IsControlInstruction() ||
+        IsCapturedObject() ||
         IsSimulate() ||
         IsEnterInlined() ||
         IsLeaveInlined());

diff --git a/test/mjsunit/regress/regress-captured-object-no-dummy-use.js b/test/mjsunit/regress/regress-captured-object-no-dummy-use.js
new file mode 100644 (file)
index 0000000..cdf548d
--- /dev/null
+++ b/test/mjsunit/regress/regress-captured-object-no-dummy-use.js
@@ -0,0 +1,18 @@
+// Copyright 2014 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
+
+var global = "10.1";
+function f() { }
+function g(a) { this.d = a; }
+function h() {
+  var x = new f();
+  global.dummy = this;
+  var y = new g(x);
+}
+h();
+h();
+%OptimizeFunctionOnNextCall(h);
+h();