Move function prototype handling into a special handler rather than IC

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 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/v8.h"
 
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/arm64/lithium-gap-resolver-arm64.h"
 #include "src/code-stubs.h"
 #include "src/hydrogen-osr.h"
@@ skipping 3314 matching lines @@
     }
   }
 }
 
 
 void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
   Register function = ToRegister(instr->function());
   Register result = ToRegister(instr->result());
   Register temp = ToRegister(instr->temp());
 
-  // Check that the function really is a function. Leaves map in the result
-  // register.
-  __ CompareObjectType(function, result, temp, JS_FUNCTION_TYPE);
-  DeoptimizeIf(ne, instr->environment());
-
-  // Make sure that the function has an instance prototype.
-  Label non_instance;
-  __ Ldrb(temp, FieldMemOperand(result, Map::kBitFieldOffset));
-  __ Tbnz(temp, Map::kHasNonInstancePrototype, &non_instance);
-
   // Get the prototype or initial map from the function.
   __ Ldr(result, FieldMemOperand(function,
                                  JSFunction::kPrototypeOrInitialMapOffset));
 
   // Check that the function has a prototype or an initial map.
   DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex,
                    instr->environment());
 
   // If the function does not have an initial map, we're done.
   Label done;
   __ CompareObjectType(result, temp, temp, MAP_TYPE);
   __ B(ne, &done);
 
   // Get the prototype from the initial map.
   __ Ldr(result, FieldMemOperand(result, Map::kPrototypeOffset));
-  __ B(&done);
-
-  // Non-instance prototype: fetch prototype from constructor field in initial
-  // map.
-  __ Bind(&non_instance);
-  __ Ldr(result, FieldMemOperand(result, Map::kConstructorOffset));
 
   // All done.
   __ Bind(&done);
 }
 
 
 void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   Register result = ToRegister(instr->result());
   __ Mov(result, Operand(Handle<Object>(instr->hydrogen()->cell().handle())));
   __ Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
@@ skipping 2678 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 
 } }  // namespace v8::internal