Implement elements transitions in ia32 Array constructor with n args.

src/ia32/builtins-ia32.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 1070 matching lines @@
 // This function is used for both construct and normal calls of Array. Whether
 // it is a construct call or not is indicated by the construct_call parameter.
 // The only difference between handling a construct call and a normal call is
 // that for a construct call the constructor function in edi needs to be
 // preserved for entering the generic code. In both cases argc in eax needs to
 // be preserved.
 static void ArrayNativeCode(MacroAssembler* masm,
                             bool construct_call,
                             Label* call_generic_code) {
   Label argc_one_or_more, argc_two_or_more, prepare_generic_code_call,
-        empty_array, not_empty_array;
+      empty_array, not_empty_array, finish, cant_transition_map, not_double;
 
   // Push the constructor and argc. No need to tag argc as a smi, as there will
   // be no garbage collection with this on the stack.
   int push_count = 0;
   if (construct_call) {
     push_count++;
     __ push(edi);
   }
   push_count++;
   __ push(eax);
@@ skipping 129 matching lines @@
   __ jmp(&entry);
   __ bind(&loop);
   __ mov(eax, Operand(edi, ecx, times_pointer_size, 0));
   if (FLAG_smi_only_arrays) {
     __ JumpIfNotSmi(eax, &has_non_smi_element);
   }
   __ mov(Operand(edx, 0), eax);
   __ add(edx, Immediate(kPointerSize));
   __ bind(&entry);
   __ dec(ecx);
-  __ j(greater_equal, &loop);
+  __ j(greater_equal, &loop, Label::kNear);
 
   // Remove caller arguments from the stack and return.
   // ebx: argc
   // esp[0]: JSArray
   // esp[4]: argc
   // esp[8]: constructor (only if construct_call)
   // esp[12]: return address
   // esp[16]: last argument
+  __ bind(&finish);
   __ mov(ecx, Operand(esp, last_arg_offset - kPointerSize));
   __ pop(eax);
   __ pop(ebx);
   __ lea(esp, Operand(esp, ebx, times_pointer_size,
                       last_arg_offset - kPointerSize));
   __ jmp(ecx);
 
   __ bind(&has_non_smi_element);
+  // Double values are handled by the runtime.
+  __ CheckMap(eax,
+              masm->isolate()->factory()->heap_number_map(),
+              &not_double,
+              DONT_DO_SMI_CHECK);
+  __ bind(&cant_transition_map);
   // Throw away the array that's only been partially constructed.
   __ pop(eax);
   __ UndoAllocationInNewSpace(eax);
+  __ jmp(&prepare_generic_code_call);
+
+  __ bind(&not_double);
+  // Transition FAST_SMI_ONLY_ELEMENTS to FAST_ELEMENTS
+  __ mov(ebx, Operand(esp, 0));
+  __ mov(edi, FieldOperand(ebx, HeapObject::kMapOffset));
+  __ LoadTransitionedArrayMapConditional(
+      FAST_SMI_ONLY_ELEMENTS,
+      FAST_ELEMENTS,
+      edi,
+      eax,
+      &cant_transition_map);
+  __ mov(FieldOperand(ebx, HeapObject::kMapOffset), edi);
+  __ RecordWriteField(ebx, HeapObject::kMapOffset, edi, eax,

[Yang, 2012/02/10 10:25:14]

where does the value of eax come from?

+                      kDontSaveFPRegs, OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+
+  // Prepare to re-enter the loop
+  __ lea(edi, Operand(esp, last_arg_offset));
+
+  // Finish the array initialization loop.
+  Label loop2;
+  __ bind(&loop2);
+  __ mov(eax, Operand(edi, ecx, times_pointer_size, 0));
+  __ mov(Operand(edx, 0), eax);
+  __ add(edx, Immediate(kPointerSize));
+  __ dec(ecx);
+  __ j(greater_equal, &loop2, Label::kNear);
+  __ jmp(&finish);
 
   // Restore argc and constructor before running the generic code.
   __ bind(&prepare_generic_code_call);
   __ pop(eax);
   if (construct_call) {
     __ pop(edi);
   }
   __ jmp(call_generic_code);
 }
 
@@ skipping 414 matching lines @@
   Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
   generator.Generate();
 }
 
 
 #undef __
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32