Direct load of global function prototype.

src/x64/stub-cache-x64.cc

 // Copyright 2010 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 96 matching lines @@
   // Load the function from the global context.
   __ movq(prototype, Operand(prototype, Context::SlotOffset(index)));
   // Load the initial map.  The global functions all have initial maps.
   __ movq(prototype,
              FieldOperand(prototype, JSFunction::kPrototypeOrInitialMapOffset));
   // Load the prototype from the initial map.
   __ movq(prototype, FieldOperand(prototype, Map::kPrototypeOffset));
 }
 
 
+void StubCompiler::GenerateDirectLoadGlobalFunctionPrototype(
+    MacroAssembler* masm, int index, Register prototype) {
+  // Get the global function with the given index.
+  JSFunction* function = JSFunction::cast(Top::global_context()->get(index));
+  // Load its initial map. The global functions all have initial maps.
+  __ Move(prototype, Handle<Map>(function->initial_map()));
+  // Load the prototype from the initial map.
+  __ movq(prototype, FieldOperand(prototype, Map::kPrototypeOffset));
+}
+
+
 // Load a fast property out of a holder object (src). In-object properties
 // are loaded directly otherwise the property is loaded from the properties
 // fixed array.
 void StubCompiler::GenerateFastPropertyLoad(MacroAssembler* masm,
                                             Register dst, Register src,
                                             JSObject* holder, int index) {
   // Adjust for the number of properties stored in the holder.
   index -= holder->map()->inobject_properties();
   if (index < 0) {
     // Get the property straight out of the holder.
@@ skipping 642 matching lines @@
 
     case STRING_CHECK:
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         // Check that the object is a two-byte string or a symbol.
         __ CmpObjectType(rdx, FIRST_NONSTRING_TYPE, rax);
         __ j(above_equal, &miss);
         // Check that the maps starting from the prototype haven't changed.
-        GenerateLoadGlobalFunctionPrototype(masm(),
-                                            Context::STRING_FUNCTION_INDEX,
-                                            rax);
+        GenerateDirectLoadGlobalFunctionPrototype(
+            masm(), Context::STRING_FUNCTION_INDEX, rax);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), rax, holder,
                         rbx, rdx, name, &miss);
       }
       break;
 
     case NUMBER_CHECK: {
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         Label fast;
         // Check that the object is a smi or a heap number.
         __ JumpIfSmi(rdx, &fast);
         __ CmpObjectType(rdx, HEAP_NUMBER_TYPE, rax);
         __ j(not_equal, &miss);
         __ bind(&fast);
         // Check that the maps starting from the prototype haven't changed.
-        GenerateLoadGlobalFunctionPrototype(masm(),
-                                            Context::NUMBER_FUNCTION_INDEX,
-                                            rax);
+        GenerateDirectLoadGlobalFunctionPrototype(
+            masm(), Context::NUMBER_FUNCTION_INDEX, rax);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), rax, holder,
                         rbx, rdx, name, &miss);
       }
       break;
     }
 
     case BOOLEAN_CHECK: {
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         Label fast;
         // Check that the object is a boolean.
         __ CompareRoot(rdx, Heap::kTrueValueRootIndex);
         __ j(equal, &fast);
         __ CompareRoot(rdx, Heap::kFalseValueRootIndex);
         __ j(not_equal, &miss);
         __ bind(&fast);
         // Check that the maps starting from the prototype haven't changed.
-        GenerateLoadGlobalFunctionPrototype(masm(),
-                                            Context::BOOLEAN_FUNCTION_INDEX,
-                                            rax);
+        GenerateDirectLoadGlobalFunctionPrototype(
+            masm(), Context::BOOLEAN_FUNCTION_INDEX, rax);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), rax, holder,
                         rbx, rdx, name, &miss);
       }
       break;
     }
 
     default:
       UNREACHABLE();
   }
 
@@ skipping 1483 matching lines @@
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64