Synchronize Compare-Literal behavior in FullCodegen and Hydrogen

BUG=chromium:260345
R=danno@chromium.org

Review URL: https://codereview.chromium.org/19582002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15723 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -8132,68 +8132,16 @@ void HOptimizedGraphBuilder::VisitArithmeticExpression(BinaryOperation* expr) {
 
 
 void HOptimizedGraphBuilder::HandleLiteralCompareTypeof(CompareOperation* expr,
-                                                        HTypeof* typeof_expr,
+                                                        Expression* sub_expr,
                                                         Handle<String> check) {
-  // Note: The HTypeof itself is removed during canonicalization, if possible.
+  CHECK_ALIVE(VisitForValue(sub_expr));
-  HValue* value = typeof_expr->value();
+  HValue* value = Pop();
   HTypeofIsAndBranch* instr = new(zone()) HTypeofIsAndBranch(value, check);
   instr->set_position(expr->position());
   return ast_context()->ReturnControl(instr, expr->id());
 }
 
 
-static bool MatchLiteralCompareNil(HValue* left,
-                                   Token::Value op,
-                                   HValue* right,
-                                   Handle<Object> nil,
-                                   HValue** expr) {
-  if (left->IsConstant() &&
-      HConstant::cast(left)->handle().is_identical_to(nil) &&
-      Token::IsEqualityOp(op)) {
-    *expr = right;
-    return true;
-  }
-  return false;
-}
-
-
-static bool MatchLiteralCompareTypeof(HValue* left,
-                                      Token::Value op,
-                                      HValue* right,
-                                      HTypeof** typeof_expr,
-                                      Handle<String>* check) {
-  if (left->IsTypeof() &&
-      Token::IsEqualityOp(op) &&
-      right->IsConstant() &&
-      HConstant::cast(right)->handle()->IsString()) {
-    *typeof_expr = HTypeof::cast(left);
-    *check = Handle<String>::cast(HConstant::cast(right)->handle());
-    return true;
-  }
-  return false;
-}
-
-
-static bool IsLiteralCompareTypeof(HValue* left,
-                                   Token::Value op,
-                                   HValue* right,
-                                   HTypeof** typeof_expr,
-                                   Handle<String>* check) {
-  return MatchLiteralCompareTypeof(left, op, right, typeof_expr, check) ||
-      MatchLiteralCompareTypeof(right, op, left, typeof_expr, check);
-}
-
-
-static bool IsLiteralCompareNil(HValue* left,
-                                Token::Value op,
-                                HValue* right,
-                                Handle<Object> nil,
-                                HValue** expr) {
-  return MatchLiteralCompareNil(left, op, right, nil, expr) ||
-      MatchLiteralCompareNil(right, op, left, nil, expr);
-}
-
-
 static bool IsLiteralCompareBool(HValue* left,
                                  Token::Value op,
                                  HValue* right) {
@@ -8207,6 +8155,22 @@ void HOptimizedGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
+
+  // Check for a few fast cases. The AST visiting behavior must be in sync
+  // with the full codegen: We don't push both left and right values onto
+  // the expression stack when one side is a special-case literal.
+  Expression* sub_expr = NULL;
+  Handle<String> check;
+  if (expr->IsLiteralCompareTypeof(&sub_expr, &check)) {
+    return HandleLiteralCompareTypeof(expr, sub_expr, check);
+  }
+  if (expr->IsLiteralCompareUndefined(&sub_expr)) {
+    return HandleLiteralCompareNil(expr, sub_expr, kUndefinedValue);
+  }
+  if (expr->IsLiteralCompareNull(&sub_expr)) {
+    return HandleLiteralCompareNil(expr, sub_expr, kNullValue);
+  }
+
   if (IsClassOfTest(expr)) {
     CallRuntime* call = expr->left()->AsCallRuntime();
     ASSERT(call->arguments()->length() == 1);
@@ -8235,19 +8199,6 @@ void HOptimizedGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
   HValue* left = Pop();
   Token::Value op = expr->op();
 
-  HTypeof* typeof_expr = NULL;
-  Handle<String> check;
-  if (IsLiteralCompareTypeof(left, op, right, &typeof_expr, &check)) {
-    return HandleLiteralCompareTypeof(expr, typeof_expr, check);
-  }
-  HValue* sub_expr = NULL;
-  Factory* f = isolate()->factory();
-  if (IsLiteralCompareNil(left, op, right, f->undefined_value(), &sub_expr)) {
-    return HandleLiteralCompareNil(expr, sub_expr, kUndefinedValue);
-  }
-  if (IsLiteralCompareNil(left, op, right, f->null_value(), &sub_expr)) {
-    return HandleLiteralCompareNil(expr, sub_expr, kNullValue);
-  }
   if (IsLiteralCompareBool(left, op, right)) {
     HCompareObjectEqAndBranch* result =
         new(zone()) HCompareObjectEqAndBranch(left, right);
@@ -8374,12 +8325,14 @@ void HOptimizedGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
 
 
 void HOptimizedGraphBuilder::HandleLiteralCompareNil(CompareOperation* expr,
-                                                     HValue* value,
+                                                     Expression* sub_expr,
                                                      NilValue nil) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(expr->op() == Token::EQ || expr->op() == Token::EQ_STRICT);
+  CHECK_ALIVE(VisitForValue(sub_expr));
+  HValue* value = Pop();
   HIfContinuation continuation;
   if (expr->op() == Token::EQ_STRICT) {
     IfBuilder if_nil(this);

src/hydrogen.h

@@ -1765,10 +1765,10 @@ class HOptimizedGraphBuilder: public HGraphBuilder, public AstVisitor {
                                        SmallMapList* types,
                                        Handle<String> name);
   void HandleLiteralCompareTypeof(CompareOperation* expr,
-                                  HTypeof* typeof_expr,
+                                  Expression* sub_expr,
                                   Handle<String> check);
   void HandleLiteralCompareNil(CompareOperation* expr,
-                               HValue* value,
+                               Expression* sub_expr,
                                NilValue nil);
 
   HInstruction* BuildStringCharCodeAt(HValue* context,

test/mjsunit/regress/regress-crbug-260345.js

@@ -0,0 +1,59 @@
+// Copyright 2013 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.
+
+var steps = 100000;
+var undefined_values = [undefined, "go on"];
+var null_values = [null, "go on"];
+
+function get_undefined_object(i) {
+  return undefined_values[(i / steps) | 0];
+}
+
+function test_undefined() {
+  var objects = 0;
+  for (var i = 0; i < 2 * steps; i++) {
+    undefined == get_undefined_object(i) && objects++;
+  }
+  return objects;
+}
+
+assertEquals(steps, test_undefined());
+
+
+function get_null_object(i) {
+  return null_values[(i / steps) | 0];
+}
+
+function test_null() {
+  var objects = 0;
+  for (var i = 0; i < 2 * steps; i++) {
+    null == get_null_object(i) && objects++;
+  }
+  return objects;
+}
+
+assertEquals(steps, test_null());