Fix treatment of const variables in assigned variable analysis.

Const variables are not considered as trivial sub-expressions since
we have the check for the hole value as a side-effect.

Review URL: http://codereview.chromium.org/849003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4112 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/data-flow.cc b/src/data-flow.cc
index 434991c..cfc7286 100644 (file)
--- a/src/data-flow.cc
+++ b/src/data-flow.cc
@@ -1129,6 +1129,7 @@ void AssignedVariablesAnalyzer::MarkIfTrivial(Expression* expr) {
   if (var != NULL &&
       var->IsStackAllocated() &&
       !var->is_arguments() &&
+      var->mode() != Variable::CONST &&
       (var->is_this() || !av_.Contains(BitIndex(var)))) {
     expr->AsVariableProxy()->set_is_trivial(true);
   }

diff --git a/test/mjsunit/regress/regress-641.js b/test/mjsunit/regress/regress-641.js
new file mode 100644 (file)
index 0000000..957caa8
--- /dev/null
+++ b/test/mjsunit/regress/regress-641.js
@@ -0,0 +1,35 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * 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.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+// OWNER OR 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.
+
+// Regression test for http://code.google.com/p/v8/issues/detail?id=641.
+
+ function f(){
+ while (window + 1) {
+   const window=[,];
+ }
+}
+f()