New class for Date objects: caches individual date components.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 4387a321a232098c971605e1d22064d236f5378b..2c237a32daaf8c0dbb384d20149d3dcf60908039 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -2820,6 +2820,25 @@ void FullCodeGenerator::EmitValueOf(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitDateField(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 2);
+  ASSERT_NE(NULL, args->at(1)->AsLiteral());
+  int index = Smi::cast(*(args->at(1)->AsLiteral()->handle()))->value();
+
+  VisitForAccumulatorValue(args->at(0));  // Load the object.
+
+#ifdef DEBUG
+  __ AbortIfSmi(rax);
+  __ CmpObjectType(rax, JS_DATE_TYPE, rbx);
+  __ Assert(equal, "Trying to get date field from non-date.");
+#endif
+
+  __ movq(rax, FieldOperand(rax, JSDate::kValueOffset + kPointerSize * index));
+  context()->Plug(rax);
+}
+
+
 void FullCodeGenerator::EmitMathPow(CallRuntime* expr) {
   // Load the arguments on the stack and call the runtime function.
   ZoneList<Expression*>* args = expr->arguments();
@@ -2860,6 +2879,36 @@ void FullCodeGenerator::EmitSetValueOf(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitSetDateField(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 3);
+  ASSERT_NE(NULL, args->at(1)->AsLiteral());
+  int index = Smi::cast(*(args->at(1)->AsLiteral()->handle()))->value();
+
+  VisitForStackValue(args->at(0));  // Load the object.
+  VisitForAccumulatorValue(args->at(2));  // Load the value.
+  __ pop(rbx);  // rax = value. rbx = object.
+
+#ifdef DEBUG
+  __ AbortIfSmi(rbx);
+  __ CmpObjectType(rbx, JS_DATE_TYPE, rcx);
+  __ Assert(equal, "Trying to set date field on non-date.");
+#endif
+
+  // Store the value.
+  __ movq(FieldOperand(rbx, JSDate::kValueOffset + kPointerSize * index), rax);
+  // Caches can only be smi or NaN, so we can skip the write barrier for them.
+  if (index < JSDate::kFirstBarrierFree) {
+    // Update the write barrier.  Save the value as it will be
+    // overwritten by the write barrier code and is needed afterward.
+    __ movq(rdx, rax);
+    __ RecordWriteField(rbx, JSDate::kValueOffset + kPointerSize * index,
+                        rdx, rcx, kDontSaveFPRegs);
+  }
+  context()->Plug(rax);
+}
+
+
 void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   ASSERT_EQ(args->length(), 1);