Check for overflow when bumping new space's top in inlined allocation....

src/x64/macro-assembler-x64.cc

 // Copyright 2010 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 2080 matching lines @@
 
   // Load address of new object into result.
   LoadAllocationTopHelper(result, scratch, flags);
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
 
   Register top_reg = result_end.is_valid() ? result_end : result;
 
-  if (top_reg.is(result)) {
-    addq(top_reg, Immediate(object_size));
-  } else {
-    lea(top_reg, Operand(result, object_size));
+  if (!top_reg.is(result)) {
+    movq(top_reg, result);
   }
+  addq(top_reg, Immediate(object_size));
+  j(carry, gc_required);
   movq(kScratchRegister, new_space_allocation_limit);
   cmpq(top_reg, Operand(kScratchRegister, 0));
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(top_reg, scratch);
 
   if (top_reg.is(result)) {
     if ((flags & TAG_OBJECT) != 0) {
       subq(result, Immediate(object_size - kHeapObjectTag));
@@ skipping 29 matching lines @@
     return;
   }
   ASSERT(!result.is(result_end));
 
   // Load address of new object into result.
   LoadAllocationTopHelper(result, scratch, flags);
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
-  lea(result_end, Operand(result, element_count, element_size, header_size));
+
+  // We assume that element_count*element_size + header_size does not
+  // overflow.
+  lea(result_end, Operand(element_count, element_size, header_size));
+  addq(result_end, result);
+  j(carry, gc_required);
   movq(kScratchRegister, new_space_allocation_limit);
   cmpq(result_end, Operand(kScratchRegister, 0));
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch);
 
   // Tag the result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     addq(result, Immediate(kHeapObjectTag));
@@ skipping 25 matching lines @@
   // Load address of new object into result.
   LoadAllocationTopHelper(result, scratch, flags);
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
   if (!object_size.is(result_end)) {
     movq(result_end, object_size);
   }
   addq(result_end, result);
+  j(carry, gc_required);
   movq(kScratchRegister, new_space_allocation_limit);
   cmpq(result_end, Operand(kScratchRegister, 0));
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch);
 
   // Tag the result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     addq(result, Immediate(kHeapObjectTag));
@@ skipping 261 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64