Active smi-only optimizations for large array literals.

src/x64/stub-cache-x64.cc

 // Copyright 2011 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 1442 matching lines @@
       __ lea(rdx, FieldOperand(rbx,
                                rax, times_pointer_size,
                                FixedArray::kHeaderSize - argc * kPointerSize));
       __ movq(Operand(rdx, 0), rcx);
 
       __ Integer32ToSmi(rax, rax);  // Return new length as smi.
       __ ret((argc + 1) * kPointerSize);
 
       __ bind(&with_write_barrier);
 
-      if (FLAG_smi_only_arrays) {
-        __ movq(rdi, FieldOperand(rdx, HeapObject::kMapOffset));
-        __ CheckFastObjectElements(rdi, &call_builtin);
-      }
+      __ movq(rdi, FieldOperand(rdx, HeapObject::kMapOffset));
+      __ CheckFastObjectElements(rdi, &call_builtin);
 
       // Save new length.
       __ Integer32ToSmiField(FieldOperand(rdx, JSArray::kLengthOffset), rax);
 
       // Push the element.
       __ lea(rdx, FieldOperand(rbx,
                                rax, times_pointer_size,
                                FixedArray::kHeaderSize - argc * kPointerSize));
       __ movq(Operand(rdx, 0), rcx);
 
       __ RecordWrite(
           rbx, rdx, rcx, kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
 
       __ Integer32ToSmi(rax, rax);  // Return new length as smi.
       __ ret((argc + 1) * kPointerSize);
 
       __ bind(&attempt_to_grow_elements);
       if (!FLAG_inline_new) {
         __ jmp(&call_builtin);
       }
 
       __ movq(rdi, Operand(rsp, argc * kPointerSize));
-      if (FLAG_smi_only_arrays) {
-        // Growing elements that are SMI-only requires special handling in case
-        // the new element is non-Smi. For now, delegate to the builtin.
-        Label no_fast_elements_check;
-        __ JumpIfSmi(rdi, &no_fast_elements_check);
-        __ movq(rsi, FieldOperand(rdx, HeapObject::kMapOffset));
-        __ CheckFastObjectElements(rsi, &call_builtin, Label::kFar);
-        __ bind(&no_fast_elements_check);
-      }
+      // Growing elements that are SMI-only requires special handling in case
+      // the new element is non-Smi. For now, delegate to the builtin.
+      Label no_fast_elements_check;
+      __ JumpIfSmi(rdi, &no_fast_elements_check);
+      __ movq(rsi, FieldOperand(rdx, HeapObject::kMapOffset));
+      __ CheckFastObjectElements(rsi, &call_builtin, Label::kFar);
+      __ bind(&no_fast_elements_check);
 
       ExternalReference new_space_allocation_top =
           ExternalReference::new_space_allocation_top_address(isolate());
       ExternalReference new_space_allocation_limit =
           ExternalReference::new_space_allocation_limit_address(isolate());
 
       const int kAllocationDelta = 4;
       // Load top.
       __ Load(rcx, new_space_allocation_top);
 
@@ skipping 2281 matching lines @@
       masm->isolate()->builtins()->KeyedStoreIC_MissForceGeneric();
   __ jmp(ic_force_generic, RelocInfo::CODE_TARGET);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64