[turbofan] Materialize JSFunction from frame if possible.

src/compiler/x64/code-generator-x64.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/compiler/code-generator.h"
 
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/scopes.h"
@@ skipping 1446 matching lines @@
         case Constant::kExternalReference:
           __ Move(dst, src.ToExternalReference());
           break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           if (info()->IsOptimizing() &&
               src_object.is_identical_to(info()->context())) {
             // Loading the context from the frame is way cheaper than
             // materializing the actual context heap object address.
             __ movp(dst, Operand(rbp, StandardFrameConstants::kContextOffset));
+          } else if (info()->IsOptimizing() &&
+                     src_object.is_identical_to(info()->closure())) {
+            // Loading the JSFunction from the frame is way cheaper than
+            // materializing the actual JSFunction heap object address.
+            __ movp(dst,
+                    Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
           } else {
             __ Move(dst, src_object);
           }
           break;
         }
         case Constant::kRpoNumber:
           UNREACHABLE();  // TODO(dcarney): load of labels on x64.
           break;
       }
       if (destination->IsStackSlot()) {
@@ skipping 115 matching lines @@
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace compiler
 }  // namespace v8