Supporting AllocationSiteInfo for Nested arrays

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 463 matching lines @@
     __ Assert(equal, message);
     __ pop(rcx);
   }
 
   GenerateFastCloneShallowArrayCommon(masm, length_, mode,
                                       allocation_site_mode_,
                                       &slow_case);
   __ ret(3 * kPointerSize);
 
   __ bind(&slow_case);
-  __ TailCallRuntime(Runtime::kCreateArrayLiteralShallow, 3, 1);
+
+  // Add a flags argument, carefully preserving the return address on the stack.
+  int flags = allocation_site_mode_ == TRACK_ALLOCATION_SITE

[danno, 2013/02/11 15:05:21]

Check FLAG_track_allocation_sites here, never setting kAllocationSiteInfoAllowed
(or the renamed version) if it's false.

[mvstanton, 2013/02/15 07:36:43]

With some other changes already present, I think I won't have to do that: the
allocation_site_mode_ variable won't be set to TRACK_ALLOCATION_SITE if the flag
is false. The flag guards all places where explicit direction to do something
allocation-site-wise is recorded in data structures, making it redundant to
check the flag again given an explicit directive. Does that sound like a good
approach?

+      ? ArrayLiteral::kAllocationSiteInfoAllowed
+      : ArrayLiteral::kNoFlags;
+  __ pop(rcx);
+  __ Push(Smi::FromInt(flags));
+  __ push(rcx);
+  __ TailCallRuntime(Runtime::kCreateArrayLiteralShallow, 4, 1);
 }
 
 
 void FastCloneShallowObjectStub::Generate(MacroAssembler* masm) {
   // Stack layout on entry:
   //
   // [rsp + kPointerSize]: object literal flags.
   // [rsp + (2 * kPointerSize)]: constant properties.
   // [rsp + (3 * kPointerSize)]: literal index.
   // [rsp + (4 * kPointerSize)]: literals array.
@@ skipping 6217 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64