Improve the generated code for the instanceof operator.

src/stub-cache-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 214 matching lines @@
   __ shl(eax, kSmiTagSize);
   __ ret(0);
 }
 
 
 void StubCompiler::GenerateLoadFunctionPrototype(MacroAssembler* masm,
                                                  Register receiver,
                                                  Register scratch1,
                                                  Register scratch2,
                                                  Label* miss_label) {
-  // Check that the receiver isn't a smi.
-  __ test(receiver, Immediate(kSmiTagMask));
-  __ j(zero, miss_label, not_taken);
 
-  // Check that the receiver is a function.
-  __ mov(scratch1, FieldOperand(receiver, HeapObject::kMapOffset));
-  __ movzx_b(scratch2, FieldOperand(scratch1, Map::kInstanceTypeOffset));
-  __ cmp(scratch2, JS_FUNCTION_TYPE);
-  __ j(not_equal, miss_label, not_taken);
-
-  // Make sure that the function has an instance prototype.
-  Label non_instance;
-  __ movzx_b(scratch2, FieldOperand(scratch1, Map::kBitFieldOffset));
-  __ test(scratch2, Immediate(1 << Map::kHasNonInstancePrototype));
-  __ j(not_zero, &non_instance, not_taken);
-
-  // Get the prototype or initial map from the function.
-  __ mov(scratch1,
-         FieldOperand(receiver, JSFunction::kPrototypeOrInitialMapOffset));
-
-  // If the prototype or initial map is the hole, don't return it and
-  // simply miss the cache instead. This will allow us to allocate a
-  // prototype object on-demand in the runtime system.
-  __ cmp(Operand(scratch1), Immediate(Factory::the_hole_value()));
-  __ j(equal, miss_label, not_taken);
+  __ TryGetFunctionPrototype(receiver, scratch1, scratch2, miss_label);
   __ mov(eax, Operand(scratch1));
-
-  // If the function does not have an initial map, we're done.
-  Label done;
-  __ mov(scratch1, FieldOperand(eax, HeapObject::kMapOffset));
-  __ movzx_b(scratch2, FieldOperand(scratch1, Map::kInstanceTypeOffset));
-  __ cmp(scratch2, MAP_TYPE);
-  __ j(not_equal, &done);
-
-  // Get the prototype from the initial map.
-  __ mov(eax, FieldOperand(eax, Map::kPrototypeOffset));
-
-  // All done: Return the prototype.
-  __ bind(&done);
-  __ ret(0);
-
-  // Non-instance prototype: Fetch prototype from constructor field
-  // in initial map.
-  __ bind(&non_instance);
-  __ mov(eax, FieldOperand(scratch1, Map::kConstructorOffset));
   __ ret(0);
 }
 
 
 void StubCompiler::GenerateLoadField(MacroAssembler* masm,
                                      JSObject* object,
                                      JSObject* holder,
                                      Register receiver,
                                      Register scratch1,
                                      Register scratch2,
@@ skipping 964 matching lines @@
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);
 
   // Return the generated code.
   return GetCode(CALLBACKS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal