MIPS: Only create arguments-maps in the bootstrapper, remove now obsolete ValueType flag.

Port r22245 (1471c64)

BUG=
R=palfia@homejinni.com

Review URL: https://codereview.chromium.org/375603002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22253 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -2144,12 +2144,12 @@ void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
   __ Allocate(t5, v0, a3, t0, &runtime, TAG_OBJECT);
 
   // v0 = address of new object(s) (tagged)
-  // a2 = argument count (tagged)
+  // a2 = argument count (smi-tagged)
   // Get the arguments boilerplate from the current native context into t0.
   const int kNormalOffset =
-      Context::SlotOffset(Context::SLOPPY_ARGUMENTS_BOILERPLATE_INDEX);
+      Context::SlotOffset(Context::SLOPPY_ARGUMENTS_MAP_INDEX);
   const int kAliasedOffset =
-      Context::SlotOffset(Context::ALIASED_ARGUMENTS_BOILERPLATE_INDEX);
+      Context::SlotOffset(Context::ALIASED_ARGUMENTS_MAP_INDEX);
 
   __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ lw(t0, FieldMemOperand(t0, GlobalObject::kNativeContextOffset));
@@ -2164,22 +2164,23 @@ void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
 
   // v0 = address of new object (tagged)
   // a1 = mapped parameter count (tagged)
-  // a2 = argument count (tagged)
-  // t0 = address of boilerplate object (tagged)
-  // Copy the JS object part.
-  for (int i = 0; i < JSObject::kHeaderSize; i += kPointerSize) {
-    __ lw(a3, FieldMemOperand(t0, i));
-    __ sw(a3, FieldMemOperand(v0, i));
-  }
+  // a2 = argument count (smi-tagged)
+  // t0 = address of arguments map (tagged)
+  __ sw(t0, FieldMemOperand(v0, JSObject::kMapOffset));
+  __ LoadRoot(a3, Heap::kEmptyFixedArrayRootIndex);
+  __ sw(a3, FieldMemOperand(v0, JSObject::kPropertiesOffset));
+  __ sw(a3, FieldMemOperand(v0, JSObject::kElementsOffset));
 
   // Set up the callee in-object property.
   STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
   __ lw(a3, MemOperand(sp, 2 * kPointerSize));
+  __ AssertNotSmi(a3);
   const int kCalleeOffset = JSObject::kHeaderSize +
       Heap::kArgumentsCalleeIndex * kPointerSize;
   __ sw(a3, FieldMemOperand(v0, kCalleeOffset));
 
   // Use the length (smi tagged) and set that as an in-object property too.
+  __ AssertSmi(a2);
   STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
   const int kLengthOffset = JSObject::kHeaderSize +
       Heap::kArgumentsLengthIndex * kPointerSize;
@@ -2338,15 +2339,18 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
   // Get the arguments boilerplate from the current native context.
   __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ lw(t0, FieldMemOperand(t0, GlobalObject::kNativeContextOffset));
-  __ lw(t0, MemOperand(t0, Context::SlotOffset(
-      Context::STRICT_ARGUMENTS_BOILERPLATE_INDEX)));
+  __ lw(t0, MemOperand(
+                t0, Context::SlotOffset(Context::STRICT_ARGUMENTS_MAP_INDEX)));
 
-  // Copy the JS object part.
-  __ CopyFields(v0, t0, a3.bit(), JSObject::kHeaderSize / kPointerSize);
+  __ sw(t0, FieldMemOperand(v0, JSObject::kMapOffset));
+  __ LoadRoot(a3, Heap::kEmptyFixedArrayRootIndex);
+  __ sw(a3, FieldMemOperand(v0, JSObject::kPropertiesOffset));
+  __ sw(a3, FieldMemOperand(v0, JSObject::kElementsOffset));
 
   // Get the length (smi tagged) and set that as an in-object property too.
   STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
   __ lw(a1, MemOperand(sp, 0 * kPointerSize));
+  __ AssertSmi(a1);
   __ sw(a1, FieldMemOperand(v0, JSObject::kHeaderSize +
       Heap::kArgumentsLengthIndex * kPointerSize));