MIPS: ES6 symbols: Implement Symbol intrinsic and basic functionality

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 7f2cf652effd517c97e82dcbcb9e4196c3f855aa..056e2eef08771114f0456e216692325fb0b847bd 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -2780,6 +2780,28 @@ void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
 }
 
 
+void FullCodeGenerator::EmitIsSymbol(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 1);
+
+  VisitForAccumulatorValue(args->at(0));
+
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  Label* fall_through = NULL;
+  context()->PrepareTest(&materialize_true, &materialize_false,
+                         &if_true, &if_false, &fall_through);
+
+  __ JumpIfSmi(v0, if_false);
+  __ GetObjectType(v0, a1, a2);
+  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
+  Split(eq, a2, Operand(SYMBOL_TYPE), if_true, if_false, fall_through);
+
+  context()->Plug(if_true, if_false);
+}
+
+
 void FullCodeGenerator::EmitIsFunction(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   ASSERT(args->length() == 1);
@@ -4329,6 +4351,10 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
       __ LoadRoot(at, Heap::kNullValueRootIndex);
       __ Branch(if_true, eq, v0, Operand(at));
     }
+    if (FLAG_harmony_symbols) {
+      __ GetObjectType(v0, v0, a1);
+      __ Branch(if_true, eq, a1, Operand(SYMBOL_TYPE));
+    }
     // Check for JS objects => true.
     __ GetObjectType(v0, v0, a1);
     __ Branch(if_false, lt, a1, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));