Take loop side-effects into account when collecting side-effects on the path between two blocks.

R=fschneider@chromium.org
BUG=100409
TEST=test/mjsunit/regress/regress-100409.js

Review URL: http://codereview.chromium.org/8395002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9778 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -1503,6 +1503,9 @@ int HGlobalValueNumberer::CollectSideEffectsOnPathsToDominatedBlock(
         block->block_id() < dominated->block_id() &&
         visited_on_paths_.Add(block->block_id())) {
       side_effects |= block_side_effects_[block->block_id()];
+      if (block->IsLoopHeader()) {
+        side_effects |= loop_side_effects_[block->block_id()];
+      }
       side_effects |= CollectSideEffectsOnPathsToDominatedBlock(
           dominator, block);
     }

test/mjsunit/regress/regress-100409.js

+// Copyright 2011 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.
+
+// Flags: --allow-natives-syntax
+
+function outer () {
+  var val = 0;
+
+  function foo () {
+    val = 0;
+    val;
+    var z = false;
+    var y = true;
+    if (!z) {
+      while (z = !z) {
+        if (y) val++;
+      }
+    }
+    return val++;
+  }
+
+  return foo;
+}
+
+
+var foo = outer();
+
+assertEquals(1, foo());
+assertEquals(1, foo());
+    %OptimizeFunctionOnNextCall(foo);
+assertEquals(1, foo());