[stubs] Port LoadFunctionPrototypeStub to CSA

src/builtins/builtins-handler.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 #include "src/code-stub-assembler.h"
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic.h"
 #include "src/ic/keyed-store-generic.h"
@@ skipping 107 matching lines @@
   Node* vector = Parameter(Descriptor::kVector);
   Node* context = Parameter(Descriptor::kContext);
 
   TailCallRuntime(Runtime::kLoadGlobalIC_Slow, context, name, slot, vector);
 }
 
 void Builtins::Generate_LoadIC_Getter_ForDeopt(MacroAssembler* masm) {
   NamedLoadHandlerCompiler::GenerateLoadViaGetterForDeopt(masm);
 }
 
+TF_BUILTIN(LoadIC_FunctionPrototype, CodeStubAssembler) {
+  typedef LoadWithVectorDescriptor Descriptor;
+
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* name = Parameter(Descriptor::kName);
+  Node* slot = Parameter(Descriptor::kSlot);
+  Node* vector = Parameter(Descriptor::kVector);
+  Node* context = Parameter(Descriptor::kContext);
+
+  Label miss(this);
+
+  Node* proto_or_map =
+      LoadObjectField(receiver, JSFunction::kPrototypeOrInitialMapOffset);
+  GotoIf(IsTheHole(proto_or_map), &miss);
+
+  Variable var_result(this, MachineRepresentation::kTagged, proto_or_map);
+  Label done(this, &var_result);
+  GotoUnless(IsMap(proto_or_map), &done);
+
+  var_result.Bind(LoadMapPrototype(proto_or_map));
+  Goto(&done);
+
+  Bind(&done);
+  Return(var_result.value());
+
+  Bind(&miss);
+  TailCallRuntime(Runtime::kLoadIC_Miss, context, receiver, name, slot, vector);
+}
+
 TF_BUILTIN(LoadIC_Miss, CodeStubAssembler) {
   typedef LoadWithVectorDescriptor Descriptor;
 
   Node* receiver = Parameter(Descriptor::kReceiver);
   Node* name = Parameter(Descriptor::kName);
   Node* slot = Parameter(Descriptor::kSlot);
   Node* vector = Parameter(Descriptor::kVector);
   Node* context = Parameter(Descriptor::kContext);
 
   TailCallRuntime(Runtime::kLoadIC_Miss, context, receiver, name, slot, vector);
@@ skipping 95 matching lines @@
   TailCallRuntime(Runtime::kStoreIC_Miss, context, value, slot, vector,
                   receiver, name);
 }
 
 void Builtins::Generate_StoreIC_Setter_ForDeopt(MacroAssembler* masm) {
   NamedStoreHandlerCompiler::GenerateStoreViaSetterForDeopt(masm);
 }
 
 }  // namespace internal
 }  // namespace v8