Make new space iterable when transitioning double array to objects

src/x64/codegen-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 351 matching lines @@
 
 void ElementsTransitionGenerator::GenerateDoubleToObject(
     MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
   // ----------- S t a t e -------------
   //  -- rax    : value
   //  -- rbx    : target map
   //  -- rcx    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
-  Label loop, entry, convert_hole, gc_required, only_change_map;
+  Label loop, entry, convert_hole, gc_required, gc_cleanup, only_change_map;
 
   if (mode == TRACK_ALLOCATION_SITE) {
     __ JumpIfJSArrayHasAllocationMemento(rdx, rdi, fail);
   }
 
   // Check for empty arrays, which only require a map transition and no changes
   // to the backing store.
   __ movp(r8, FieldOperand(rdx, JSObject::kElementsOffset));
   __ CompareRoot(r8, Heap::kEmptyFixedArrayRootIndex);
   __ j(equal, &only_change_map);
@@ skipping 12 matching lines @@
   __ Integer32ToSmi(r14, r9);
   __ movp(FieldOperand(r11, FixedArray::kLengthOffset), r14);
 
   // Prepare for conversion loop.
   __ movq(rsi, BitCast<int64_t, uint64_t>(kHoleNanInt64));
   __ LoadRoot(rdi, Heap::kTheHoleValueRootIndex);
   // rsi: the-hole NaN
   // rdi: pointer to the-hole
   __ jmp(&entry);
 
+  __ bind(&gc_cleanup);
+#ifdef VERIFY_HEAP
+  // Make sure new space is iterable if we are verifying the heap.
+  __ Move(rax, Smi::FromInt(0));
+  __ movp(FieldOperand(r11,
+                       r9,
+                       times_pointer_size,
+                       FixedArray::kHeaderSize),
+          rax);
+  __ decp(r9);
+  __ j(not_sign, &gc_cleanup);
+#endif
+
   // Call into runtime if GC is required.
   __ bind(&gc_required);
   __ Pop(rax);
   __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   __ jmp(fail);
 
   // Box doubles into heap numbers.
   __ bind(&loop);
   __ movq(r14, FieldOperand(r8,
                             r9,
                             times_8,
                             FixedDoubleArray::kHeaderSize));
   // r9 : current element's index
   // r14: current element
   __ cmpq(r14, rsi);
   __ j(equal, &convert_hole);
 
   // Non-hole double, copy value into a heap number.
-  __ AllocateHeapNumber(rax, r15, &gc_required);
+  __ AllocateHeapNumber(rax, r15, &gc_cleanup);
   // rax: new heap number
   __ movq(FieldOperand(rax, HeapNumber::kValueOffset), r14);
   __ movp(FieldOperand(r11,
                        r9,
                        times_pointer_size,
                        FixedArray::kHeaderSize),
           rax);
   __ movp(r15, r9);
   __ RecordWriteArray(r11,
                       rax,
@@ skipping 276 matching lines @@
     // argument_count_reg_ * times_pointer_size + (receiver - 1) * kPointerSize.
     return Operand(base_reg_, argument_count_reg_, times_pointer_size,
         displacement_to_last_argument + (receiver - 1 - index) * kPointerSize);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64