A number of instructions use GVN but do not provide a comparison

function for the data. This leads to wrong results where operations
are wrongly assumed to have the same value as a previous (different)
operation.

Provide the data comparison functions.

BUG=995

Review URL: http://codereview.chromium.org/5898003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6052 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.h

@@ -1430,6 +1430,12 @@ class HUnaryMathOperation: public HUnaryOperation {
 
   DECLARE_CONCRETE_INSTRUCTION(UnaryMathOperation, "unary_math_operation")
 
+ protected:
+  virtual bool DataEquals(HValue* other) const {
+    HUnaryMathOperation* b = HUnaryMathOperation::cast(other);
+    return op_ == b->op();
+  }
+
  private:
   BuiltinFunctionId op_;
 };
@@ -2097,6 +2103,12 @@ class HIsNull: public HUnaryPredicate {
 
   DECLARE_CONCRETE_INSTRUCTION(IsNull, "is_null")
 
+ protected:
+  virtual bool DataEquals(HValue* other) const {
+    HIsNull* b = HIsNull::cast(other);
+    return is_strict_ == b->is_strict();
+  }
+
  private:
   bool is_strict_;
 };
@@ -2134,6 +2146,12 @@ class HHasInstanceType: public HUnaryPredicate {
 
   DECLARE_CONCRETE_INSTRUCTION(HasInstanceType, "has_instance_type")
 
+ protected:
+  virtual bool DataEquals(HValue* other) const {
+    HHasInstanceType* b = HHasInstanceType::cast(other);
+    return (from_ == b->from()) && (to_ == b->to());
+  }
+
  private:
   InstanceType from_;
   InstanceType to_;  // Inclusive range, not all combinations work.
@@ -2159,6 +2177,12 @@ class HClassOfTest: public HUnaryPredicate {
 
   Handle<String> class_name() const { return class_name_; }
 
+ protected:
+  virtual bool DataEquals(HValue* other) const {
+    HClassOfTest* b = HClassOfTest::cast(other);
+    return class_name_.is_identical_to(b->class_name_);
+  }
+
  private:
   Handle<String> class_name_;
 };

test/mjsunit/regress/regress-995.js

+// 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.
+
+//
+// A number of hydrogen instructions did not correctly compare its
+// data during GVN.
+//
+// Flags: --allow-natives-syntax
+
+// HHasInstance.
+function f(value) {
+  if (%_IsSpecObject(value)) {
+    if ((%_IsArray(value))) assertTrue(false);
+  }
+}
+f(new String("bar"));
+
+// HClassOf.
+function g(value) {
+  if (%_ClassOf(value) === 'Date') {
+    if (%_ClassOf(value) === 'String') assertTrue(false);
+  }
+}
+g(new Date());
+
+// HIsNull.
+function h(value) {
+  if (value == null) {
+    if (value === null) assertTrue(false);
+  }
+}
+h(undefined);
+