Preserve optimized code map during GCs weakly.

src/x64/code-stubs-x64.cc

 // Copyright 2012 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 269 matching lines @@
 
   __ bind(&check_optimized);
 
   __ IncrementCounter(counters->fast_new_closure_try_optimized(), 1);
 
   // rcx holds native context, ebx points to fixed array of 3-element entries
   // (native context, optimized code, literals).
   // The optimized code map must never be empty, so check the first elements.
   Label install_optimized;
   // Speculatively move code object into edx.
-  __ movq(rdx, FieldOperand(rbx, FixedArray::kHeaderSize + kPointerSize));
-  __ cmpq(rcx, FieldOperand(rbx, FixedArray::kHeaderSize));
+  __ movq(rdx, FieldOperand(rbx, SharedFunctionInfo::kFirstCodeSlot));
+  __ cmpq(rcx, FieldOperand(rbx, SharedFunctionInfo::kFirstContextSlot));
   __ j(equal, &install_optimized);
 
   // Iterate through the rest of map backwards. rdx holds an index.
   Label loop;
   Label restore;
   __ movq(rdx, FieldOperand(rbx, FixedArray::kLengthOffset));
   __ SmiToInteger32(rdx, rdx);
   __ bind(&loop);
   // Do not double check first entry.
-  __ cmpq(rdx, Immediate(SharedFunctionInfo::kEntryLength));
+  __ cmpq(rdx, Immediate(SharedFunctionInfo::kSecondEntryIndex));
   __ j(equal, &restore);
-  __ subq(rdx, Immediate(SharedFunctionInfo::kEntryLength));  // Skip an entry.
+  __ subq(rdx, Immediate(SharedFunctionInfo::kEntryLength));
   __ cmpq(rcx, FieldOperand(rbx,
                             rdx,
                             times_pointer_size,
                             FixedArray::kHeaderSize));
   __ j(not_equal, &loop, Label::kNear);
   // Hit: fetch the optimized code.
   __ movq(rdx, FieldOperand(rbx,
                             rdx,
                             times_pointer_size,
                             FixedArray::kHeaderSize + 1 * kPointerSize));
@@ skipping 6678 matching lines @@
     __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64