Synchronize Compare-Literal behavior in FullCodegen and Hydrogen

src/hydrogen.cc

 // 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
@@ skipping 8114 matching lines @@
   CHECK_ALIVE(VisitForValue(expr->right()));
   HValue* right = Pop();
   HValue* left = Pop();
   HInstruction* instr = BuildBinaryOperation(expr, left, right);
   instr->set_position(expr->position());
   return ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HOptimizedGraphBuilder::HandleLiteralCompareTypeof(CompareOperation* expr,
-                                                        HTypeof* typeof_expr,
+                                                        Expression* sub_expr,
                                                         Handle<String> check) {
-  // Note: The HTypeof itself is removed during canonicalization, if possible.
-  HValue* value = typeof_expr->value();
+  CHECK_ALIVE(VisitForValue(sub_expr));
+  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) {
   return op == Token::EQ_STRICT &&
       ((left->IsConstant() && HConstant::cast(left)->handle()->IsBoolean()) ||
        (right->IsConstant() && HConstant::cast(right)->handle()->IsBoolean()));
 }
 
 
 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);
     CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
     HValue* value = Pop();
     Literal* literal = expr->right()->AsLiteral();
     Handle<String> rhs = Handle<String>::cast(literal->value());
     HClassOfTestAndBranch* instr =
         new(zone()) HClassOfTestAndBranch(value, rhs);
     instr->set_position(expr->position());
     return ast_context()->ReturnControl(instr, expr->id());
   }
 
   Handle<Type> left_type = expr->left()->bounds().lower;
   Handle<Type> right_type = expr->right()->bounds().lower;
   Handle<Type> combined_type = expr->combined_type();
   Representation combined_rep = Representation::FromType(combined_type);
   Representation left_rep = Representation::FromType(left_type);
   Representation right_rep = Representation::FromType(right_type);
 
   CHECK_ALIVE(VisitForValue(expr->left()));
   CHECK_ALIVE(VisitForValue(expr->right()));
 
   HValue* context = environment()->LookupContext();
   HValue* right = Pop();
   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);
     result->set_position(expr->position());
     return ast_context()->ReturnControl(result, expr->id());
   }
 
   if (op == Token::INSTANCEOF) {
     // Check to see if the rhs of the instanceof is a global function not
     // residing in new space. If it is we assume that the function will stay the
@@ skipping 106 matching lines @@
           new(zone()) HCompareNumericAndBranch(left, right, op);
       result->set_observed_input_representation(left_rep, right_rep);
       result->set_position(expr->position());
       return ast_context()->ReturnControl(result, expr->id());
     }
   }
 }
 
 
 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);
     if_nil.If<HCompareObjectEqAndBranch>(
         value, (nil == kNullValue) ? graph()->GetConstantNull()
                                    : graph()->GetConstantUndefined());
     if_nil.Then();
     if_nil.Else();
     if_nil.CaptureContinuation(&continuation);
     return ast_context()->ReturnContinuation(&continuation, expr->id());
@@ skipping 1643 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal