Only to the relevant checks in LoadFunctionPrototype

src/x64/macro-assembler-x64.cc

 // Copyright 2012 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"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 3727 matching lines @@
   movzxbl(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
   cmpb(instance_type, Immediate(static_cast<uint8_t>(LAST_NAME_TYPE)));
   return below_equal;
 }
 
 
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Label* miss,
                                              bool miss_on_bound_function) {
-  // Check that the receiver isn't a smi.
-  testl(function, Immediate(kSmiTagMask));
-  j(zero, miss);
+  Label non_instance;
+  if (miss_on_bound_function) {
+    // Check that the receiver isn't a smi.
+    testl(function, Immediate(kSmiTagMask));
+    j(zero, miss);
 
-  // Check that the function really is a function.
-  CmpObjectType(function, JS_FUNCTION_TYPE, result);
-  j(not_equal, miss);
+    // Check that the function really is a function.
+    CmpObjectType(function, JS_FUNCTION_TYPE, result);
+    j(not_equal, miss);
 
-  if (miss_on_bound_function) {
     movp(kScratchRegister,
          FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
     // It's not smi-tagged (stored in the top half of a smi-tagged 8-byte
     // field).
     TestBitSharedFunctionInfoSpecialField(kScratchRegister,
         SharedFunctionInfo::kCompilerHintsOffset,
         SharedFunctionInfo::kBoundFunction);
     j(not_zero, miss);
+
+    // Make sure that the function has an instance prototype.
+    testb(FieldOperand(result, Map::kBitFieldOffset),
+          Immediate(1 << Map::kHasNonInstancePrototype));
+    j(not_zero, &non_instance, Label::kNear);
   }
 
-  // Make sure that the function has an instance prototype.
-  Label non_instance;
-  testb(FieldOperand(result, Map::kBitFieldOffset),
-        Immediate(1 << Map::kHasNonInstancePrototype));
-  j(not_zero, &non_instance, Label::kNear);
-
   // Get the prototype or initial map from the function.
   movp(result,
        FieldOperand(function, 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.
   CompareRoot(result, Heap::kTheHoleValueRootIndex);
   j(equal, miss);
 
   // If the function does not have an initial map, we're done.
   Label done;
   CmpObjectType(result, MAP_TYPE, kScratchRegister);
   j(not_equal, &done, Label::kNear);
 
   // Get the prototype from the initial map.
   movp(result, FieldOperand(result, Map::kPrototypeOffset));
-  jmp(&done, Label::kNear);
 
-  // Non-instance prototype: Fetch prototype from constructor field
-  // in initial map.
-  bind(&non_instance);
-  movp(result, FieldOperand(result, Map::kConstructorOffset));
+  if (miss_on_bound_function) {
+    jmp(&done, Label::kNear);
+
+    // Non-instance prototype: Fetch prototype from constructor field
+    // in initial map.
+    bind(&non_instance);
+    movp(result, FieldOperand(result, Map::kConstructorOffset));
+  }
 
   // All done.
   bind(&done);
 }
 
 
 void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
   if (FLAG_native_code_counters && counter->Enabled()) {
     Operand counter_operand = ExternalOperand(ExternalReference(counter));
     movl(counter_operand, Immediate(value));
@@ skipping 1567 matching lines @@
   if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64