MIPS: Unify and simplify the FastCloneShallowArrayStub.

Port r20974 (5de4367)

Original commit message:
- Don't bake in length/capacity into full codegen calls of stubs,
allowing boilerplates to increase their capacity without regenerating
code.
- Unify all variants of the clone stub into a single,
length-independent version.
- Various tweaks to make sure that the clone stub doesn't spill and
therefore need an eager stack frame.
- Handle all lengths of array literals in the fast case.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/258813002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20991 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -82,6 +82,11 @@ void FastCloneShallowArrayStub::InitializeInterfaceDescriptor(
   static Register registers[] = { a3, a2, a1 };
   descriptor->register_param_count_ = 3;
   descriptor->register_params_ = registers;
+  static Representation representations[] = {
+      Representation::Tagged(),
+      Representation::Smi(),
+      Representation::Tagged() };
+  descriptor->register_param_representations_ = representations;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(
           Runtime::kHiddenCreateArrayLiteralStubBailout)->entry;
@@ -225,6 +230,11 @@ static void InitializeArrayConstructorDescriptor(
     descriptor->stack_parameter_count_ = a0;
     descriptor->register_param_count_ = 3;
     descriptor->register_params_ = registers_variable_args;
+    static Representation representations[] = {
+        Representation::Tagged(),
+        Representation::Tagged(),
+        Representation::Integer32() };
+    descriptor->register_param_representations_ = representations;
   }
 
   descriptor->hint_stack_parameter_count_ = constant_stack_parameter_count;
@@ -252,6 +262,10 @@ static void InitializeInternalArrayConstructorDescriptor(
     descriptor->stack_parameter_count_ = a0;
     descriptor->register_param_count_ = 2;
     descriptor->register_params_ = registers_variable_args;
+    static Representation representations[] = {
+        Representation::Tagged(),
+        Representation::Integer32() };
+    descriptor->register_param_representations_ = representations;
   }
 
   descriptor->hint_stack_parameter_count_ = constant_stack_parameter_count;

src/mips/full-codegen-mips.cc

@@ -1834,33 +1834,12 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   __ lw(a3, FieldMemOperand(a3, JSFunction::kLiteralsOffset));
   __ li(a2, Operand(Smi::FromInt(expr->literal_index())));
   __ li(a1, Operand(constant_elements));
-  if (has_fast_elements && constant_elements_values->map() ==
-      isolate()->heap()->fixed_cow_array_map()) {
-    FastCloneShallowArrayStub stub(
-        isolate(),
-        FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS,
-        allocation_site_mode,
-        length);
-    __ CallStub(&stub);
-    __ IncrementCounter(isolate()->counters()->cow_arrays_created_stub(),
-        1, a1, a2);
-  } else if (expr->depth() > 1 || Serializer::enabled() ||
-             length > FastCloneShallowArrayStub::kMaximumInlinedCloneLength) {
+  if (expr->depth() > 1) {
     __ li(a0, Operand(Smi::FromInt(flags)));
     __ Push(a3, a2, a1, a0);
     __ CallRuntime(Runtime::kHiddenCreateArrayLiteral, 4);
   } else {
-    ASSERT(IsFastSmiOrObjectElementsKind(constant_elements_kind) ||
-           FLAG_smi_only_arrays);
-    FastCloneShallowArrayStub::Mode mode =
-        FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS;
-
-    if (has_fast_elements) {
-      mode = FastCloneShallowArrayStub::CLONE_ELEMENTS;
-    }
-
-    FastCloneShallowArrayStub stub(isolate(), mode, allocation_site_mode,
-                                   length);
+    FastCloneShallowArrayStub stub(isolate(), allocation_site_mode);
     __ CallStub(&stub);
   }