From 1342cb8b00f238e71808175ba150bfb354ec7b98 Mon Sep 17 00:00:00 2001
From: "ishell@chromium.org"
 <ishell@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Wed, 19 Feb 2014 12:34:50 +0000
Subject: [PATCH] Bugfix in check elimination with a regression test.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/172173003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/hydrogen-check-elimination.cc         |  2 ++
 test/mjsunit/regress/compare-map-elim1.js | 57 +++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 test/mjsunit/regress/compare-map-elim1.js

diff --git a/src/hydrogen-check-elimination.cc b/src/hydrogen-check-elimination.cc
index f152673..6e6a84c 100644
--- a/src/hydrogen-check-elimination.cc
+++ b/src/hydrogen-check-elimination.cc
@@ -338,7 +338,9 @@ class HCheckTable : public ZoneObject {
             HCheckMaps* check = HCheckMaps::cast(entry->check_);
             TRACE(("CheckMaps #%d at B%d narrowed\n", check->id(),
                 check->block()->block_id()));
+            // Update map set and ensure that the check is alive.
             check->set_map_set(intersection, graph->zone());
+            check->ClearFlag(HValue::kIsDead);
             TRACE(("Replacing redundant CheckMaps #%d at B%d with #%d\n",
                 instr->id(), instr->block()->block_id(), entry->check_->id()));
             instr->DeleteAndReplaceWith(entry->check_);
diff --git a/test/mjsunit/regress/compare-map-elim1.js b/test/mjsunit/regress/compare-map-elim1.js
new file mode 100644
index 0000000..c7ea05d
--- /dev/null
+++ b/test/mjsunit/regress/compare-map-elim1.js
@@ -0,0 +1,57 @@
+// 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.
+
+// Flags: --allow-natives-syntax --check-elimination
+
+
+function foo(o) {
+  return o.foo1;
+}
+
+function getter() {
+  return this.x + this.z + foo2(this);
+}
+
+function foo2(o) {
+  return o.a;
+}
+
+var o1 = {z:0, x:1};
+var o2 = {z:0, a:1.5, x:1};
+var o3 = {z:0, a:1.5};
+Object.defineProperty(o1, "foo1", {get:getter});
+Object.defineProperty(o2, "foo1", {get:getter});
+
+foo(o1);
+foo(o1);
+foo(o2);
+%ClearFunctionTypeFeedback(foo2);
+foo2(o2);
+foo2(o2);
+foo2(o3);
+%OptimizeFunctionOnNextCall(foo);
+foo(o1);
-- 
2.7.4