Allow functions to have custom construct stubs that are called...

src/ia32/builtins-ia32.cc

 // Copyright 2006-2008 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 45 matching lines @@
   // -----------------------------------
 
   Label non_function_call;
   // Check that function is not a smi.
   __ test(edi, Immediate(kSmiTagMask));
   __ j(zero, &non_function_call);
   // Check that function is a JSFunction.
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
   __ j(not_equal, &non_function_call);
 
+  // Jump to the function-specific construct stub.
+  __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(ebx, FieldOperand(ebx, SharedFunctionInfo::kConstructStubOffset));
+  __ lea(ebx, FieldOperand(ebx, Code::kHeaderSize));
+  __ jmp(Operand(ebx));
+
+  // edi: called object
+  // eax: number of arguments
+  __ bind(&non_function_call);
+
+  // Set expected number of arguments to zero (not changing eax).
+  __ Set(ebx, Immediate(0));
+  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ jmp(Handle<Code>(builtin(ArgumentsAdaptorTrampoline)),
+         RelocInfo::CODE_TARGET);
+}
+
+
+void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   // Enter a construct frame.
   __ EnterConstructFrame();
 
   // Store a smi-tagged arguments count on the stack.
   __ shl(eax, kSmiTagSize);
   __ push(eax);
 
   // Push the function to invoke on the stack.
   __ push(edi);
 
@@ skipping 222 matching lines @@
   __ bind(&exit);
   __ mov(ebx, Operand(esp, kPointerSize));  // get arguments count
   __ LeaveConstructFrame();
 
   // Remove caller arguments from the stack and return.
   ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
   __ pop(ecx);
   __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
   __ push(ecx);
   __ ret(0);
-
-  // edi: called object
-  // eax: number of arguments
-  __ bind(&non_function_call);
-
-  // Set expected number of arguments to zero (not changing eax).
-  __ Set(ebx, Immediate(0));
-  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
-  __ jmp(Handle<Code>(builtin(ArgumentsAdaptorTrampoline)),
-         RelocInfo::CODE_TARGET);
 }
 
 
 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                              bool is_construct) {
   // Clear the context before we push it when entering the JS frame.
   __ xor_(esi, Operand(esi));  // clear esi
 
   // Enter an internal frame.
   __ EnterInternalFrame();
@@ skipping 434 matching lines @@
   // Dont adapt arguments.
   // -------------------------------------------
   __ bind(&dont_adapt_arguments);
   __ jmp(Operand(edx));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal