MIPS: port Better codegen for '<expression> === void <literal>'.

src/mips/full-codegen-mips.cc

Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index 1f1780ec2e5bd7b42c5a6a3ccbf155e7c9eb68ec..59e2a3601b554419d5c34356720d8d8d04d2d661 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -3983,26 +3983,13 @@ void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
   }
 }
 
-
-bool FullCodeGenerator::TryLiteralCompare(Token::Value op,
-                                          Expression* left,
-                                          Expression* right,
-                                          Label* if_true,
-                                          Label* if_false,
-                                          Label* fall_through) {
-  if (op != Token::EQ && op != Token::EQ_STRICT) return false;
-
-  // Check for the pattern: typeof <expression> == <string literal>.
-  Literal* right_literal = right->AsLiteral();
-  if (right_literal == NULL) return false;
-  Handle<Object> right_literal_value = right_literal->handle();
-  if (!right_literal_value->IsString()) return false;
-  UnaryOperation* left_unary = left->AsUnaryOperation();
-  if (left_unary == NULL || left_unary->op() != Token::TYPEOF) return false;
-  Handle<String> check = Handle<String>::cast(right_literal_value);
-
+void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
+                                                 Handle<String> check,
+                                                 Label* if_true,
+                                                 Label* if_false,
+                                                 Label* fall_through) {
   { AccumulatorValueContext context(this);
-    VisitForTypeofValue(left_unary->expression());
+    VisitForTypeofValue(expr);
   }
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
 
@@ -4056,8 +4043,18 @@ bool FullCodeGenerator::TryLiteralCompare(Token::Value op,
   } else {
     if (if_false != fall_through) __ jmp(if_false);
   }
+}
 
-  return true;
+
+void FullCodeGenerator::EmitLiteralCompareUndefined(Expression* expr,
+                                                    Label* if_true,
+                                                    Label* if_false,
+                                                    Label* fall_through) {
+  VisitForAccumulatorValue(expr);
+  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+
+  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+  Split(eq, v0, Operand(at), if_true, if_false, fall_through);
 }
 
 
@@ -4077,14 +4074,12 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
 
   // First we try a fast inlined version of the compare when one of
   // the operands is a literal.
-  Token::Value op = expr->op();
-  Expression* left = expr->left();
-  Expression* right = expr->right();
-  if (TryLiteralCompare(op, left, right, if_true, if_false, fall_through)) {
+  if (TryLiteralCompare(expr, if_true, if_false, fall_through)) {
     context()->Plug(if_true, if_false);
     return;
   }
 
+  Token::Value op = expr->op();
   VisitForStackValue(expr->left());
   switch (op) {
     case Token::IN: