[crankshaft] Properly optimize strict equality with constants.

src/crankshaft/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/crankshaft/hydrogen.h"
 
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
 #include "src/ast/ast-numbering.h"
@@ skipping 11575 matching lines @@
 void HOptimizedGraphBuilder::HandleLiteralCompareTypeof(CompareOperation* expr,
                                                         Expression* sub_expr,
                                                         Handle<String> check) {
   CHECK_ALIVE(VisitForTypeOf(sub_expr));
   SetSourcePosition(expr->position());
   HValue* value = Pop();
   HTypeofIsAndBranch* instr = New<HTypeofIsAndBranch>(value, check);
   return ast_context()->ReturnControl(instr, expr->id());
 }
 
+namespace {
 
-static bool IsLiteralCompareBool(Isolate* isolate,
-                                 HValue* left,
-                                 Token::Value op,
-                                 HValue* right) {
+bool IsLiteralCompareStrict(Isolate* isolate, HValue* left, Token::Value op,
+                            HValue* right) {
   return op == Token::EQ_STRICT &&
-      ((left->IsConstant() &&
-          HConstant::cast(left)->handle(isolate)->IsBoolean()) ||
-       (right->IsConstant() &&
-           HConstant::cast(right)->handle(isolate)->IsBoolean()));
+         ((left->IsConstant() &&
+           !HConstant::cast(left)->handle(isolate)->IsNumber() &&
+           !HConstant::cast(left)->handle(isolate)->IsSimd128Value() &&
+           !HConstant::cast(left)->handle(isolate)->IsString()) ||
+          (right->IsConstant() &&
+           !HConstant::cast(right)->handle(isolate)->IsNumber() &&
+           !HConstant::cast(right)->handle(isolate)->IsSimd128Value() &&
+           !HConstant::cast(right)->handle(isolate)->IsString()));
 }
 
+}  // namespace
 
 void HOptimizedGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
   DCHECK(!HasStackOverflow());
   DCHECK(current_block() != NULL);
   DCHECK(current_block()->HasPredecessor());
 
   if (!top_info()->is_tracking_positions()) SetSourcePosition(expr->position());
 
   // 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
@@ skipping 25 matching lines @@
   Type* right_type = bounds_.get(expr->right()).lower;
   Type* combined_type = expr->combined_type();
 
   CHECK_ALIVE(VisitForValue(expr->left()));
   CHECK_ALIVE(VisitForValue(expr->right()));
 
   HValue* right = Pop();
   HValue* left = Pop();
   Token::Value op = expr->op();
 
-  if (IsLiteralCompareBool(isolate(), left, op, right)) {
+  if (IsLiteralCompareStrict(isolate(), left, op, right)) {
     HCompareObjectEqAndBranch* result =
         New<HCompareObjectEqAndBranch>(left, right);
     return ast_context()->ReturnControl(result, expr->id());
   }
 
   if (op == Token::INSTANCEOF) {
     // Check to see if the rhs of the instanceof is a known function.
     if (right->IsConstant() &&
         HConstant::cast(right)->handle(isolate())->IsJSFunction()) {
       Handle<JSFunction> function =
@@ skipping 1975 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8