CallIC customization stubs must accept that a vector slot is cleared.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 5041d9424231961aa909bcddc5490eccc62d0924..0ff1f88a9673f444babe628de8f80849356f3621 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2255,11 +2255,14 @@ void CallIC_ArrayStub::Generate(MacroAssembler* masm) {
   __ j(not_equal, &miss);
 
   __ movp(rax, Immediate(arg_count()));
-  __ movp(rbx, FieldOperand(rbx, rdx, times_pointer_size,
+  __ movp(rcx, FieldOperand(rbx, rdx, times_pointer_size,
                             FixedArray::kHeaderSize));
-
   // Verify that ecx contains an AllocationSite
-  __ AssertUndefinedOrAllocationSite(rbx);
+  Factory* factory = masm->isolate()->factory();
+  __ Cmp(FieldOperand(rcx, 0), factory->allocation_site_map());

[Toon Verwaest, 2014/07/28 14:11:38]

HeapObject::kMapOffset?

[mvstanton, 2014/07/28 16:02:50]

Done.

+  __ j(not_equal, &miss);
+
+  __ movp(rbx, rcx);
   ArrayConstructorStub stub(masm->isolate(), arg_count());
   __ TailCallStub(&stub);