Array constructor shouldn't require a Cell, just an AllocationSite.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 183 matching lines @@
 }
 
 
 static void InitializeArrayConstructorDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor,
     int constant_stack_parameter_count) {
   // register state
   // a0 -- number of arguments
   // a1 -- function
-  // a2 -- type info cell with elements kind
+  // a2 -- allocation site with elements kind
   static Register registers_variable_args[] = { a1, a2, a0 };
   static Register registers_no_args[] = { a1, a2 };
 
   if (constant_stack_parameter_count == 0) {
     descriptor->register_param_count_ = 2;
     descriptor->register_params_ = registers_no_args;
   } else {
     // stack param count needs (constructor pointer, and single argument)
     descriptor->handler_arguments_mode_ = PASS_ARGUMENTS;
     descriptor->stack_parameter_count_ = a0;
@@ skipping 5528 matching lines @@
     // If we reached this point there is a problem.
     __ Abort(kUnexpectedElementsKindInArrayConstructor);
   } else {
     UNREACHABLE();
   }
 }
 
 
 static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
                                            AllocationSiteOverrideMode mode) {
-  // a2 - type info cell (if mode != DISABLE_ALLOCATION_SITES)
+  // a2 - allocation site (if mode != DISABLE_ALLOCATION_SITES)
   // a3 - kind (if mode != DISABLE_ALLOCATION_SITES)
   // a0 - number of arguments
   // a1 - constructor?
   // sp[0] - last argument
   Label normal_sequence;
   if (mode == DONT_OVERRIDE) {
     ASSERT(FAST_SMI_ELEMENTS == 0);
     ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
     ASSERT(FAST_ELEMENTS == 2);
     ASSERT(FAST_HOLEY_ELEMENTS == 3);
@@ skipping 18 matching lines @@
     __ TailCallStub(&stub_holey);
 
     __ bind(&normal_sequence);
     ArraySingleArgumentConstructorStub stub(initial,
                                             DISABLE_ALLOCATION_SITES);
     __ TailCallStub(&stub);
   } else if (mode == DONT_OVERRIDE) {
     // We are going to create a holey array, but our kind is non-holey.
     // Fix kind and retry (only if we have an allocation site in the cell).
     __ Addu(a3, a3, Operand(1));
-    __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
-
-    if (FLAG_debug_code) {
-      __ lw(t1, FieldMemOperand(t1, 0));
-      __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);

[Benedikt Meurer, 2014/01/20 12:24:22]

Same.

-      __ Assert(eq, kExpectedAllocationSiteInCell, t1, Operand(at));
-      __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
-    }
 
     // Save the resulting elements kind in type info. We can't just store a3
     // in the AllocationSite::transition_info field because elements kind is
     // restricted to a portion of the field...upper bits need to be left alone.
     STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
-    __ lw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
+    __ lw(t0, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
     __ Addu(t0, t0, Operand(Smi::FromInt(kFastElementsKindPackedToHoley)));
-    __ sw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
+    __ sw(t0, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
 
 
     __ bind(&normal_sequence);
     int last_index = GetSequenceIndexFromFastElementsKind(
         TERMINAL_FAST_ELEMENTS_KIND);
     for (int i = 0; i <= last_index; ++i) {
       ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
       ArraySingleArgumentConstructorStub stub(kind);
       __ TailCallStub(&stub, eq, a3, Operand(kind));
     }
@@ skipping 104 matching lines @@
     __ lw(a3, FieldMemOperand(a2, 0));
     __ Assert(eq, kExpectedPropertyCellInRegisterA2,
         a3, Operand(cell_map));
     __ bind(&okay_here);
   }
 
   Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   __ Branch(&no_info, eq, a2, Operand(at));
-  __ lw(a3, FieldMemOperand(a2, Cell::kValueOffset));
+  __ lw(a2, FieldMemOperand(a2, Cell::kValueOffset));
 
   // If the type cell is undefined, or contains anything other than an
   // AllocationSite, call an array constructor that doesn't use AllocationSites.
-  __ lw(t0, FieldMemOperand(a3, 0));
+  __ lw(t0, FieldMemOperand(a2, 0));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&no_info, ne, t0, Operand(at));
 
-  __ lw(a3, FieldMemOperand(a3, AllocationSite::kTransitionInfoOffset));
+  __ lw(a3, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
   __ SmiUntag(a3);
   STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
   __ And(a3, a3, Operand(AllocationSite::ElementsKindBits::kMask));
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
 }
 
 
@@ skipping 69 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS