Handle breaks on keyed IC loads which can have an inlined version

src/ic-ia32.cc

 // Copyright 2006-2008 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 711 matching lines @@
   __ pop(ebx);
   __ push(eax);
   __ push(ecx);
   __ push(ebx);
 
   // Perform tail call to the entry.
   __ TailCallRuntime(f, 2);
 }
 
 
+// One byte opcode for test eax,0xXXXXXXXX.
+static const byte kTestEaxByte = 0xA9;
+
+
+bool KeyedLoadIC::HasInlinedVersion(Address address) {
+  Address test_instruction_address = address + 4;  // 4 = stub address
+  return *test_instruction_address == kTestEaxByte;
+}
+
+
+void KeyedLoadIC::ClearInlinedVersion(Address address) {
+  // Insert null as the map to check for to make sure the map check fails
+  // sending control flow to the IC instead of the inlined version.
+  PatchInlinedMapCheck(address, Heap::null_value());
+}
+
+
 void KeyedLoadIC::PatchInlinedMapCheck(Address address, Object* value) {
-  static const byte kTestEaxByte = 0xA9;
   Address test_instruction_address = address + 4;  // 4 = stub address
   // The keyed load has a fast inlined case if the IC call instruction
   // is immediately followed by a test instruction.
   if (*test_instruction_address == kTestEaxByte) {
     // Fetch the offset from the test instruction to the map cmp
     // instruction.  This offset is stored in the last 4 bytes of the
     // 5 byte test instruction.
     Address offset_address = test_instruction_address + 1;
     int offset_value = *(reinterpret_cast<int*>(offset_address));
     // Compute the map address.  The map address is in the last 4
     // bytes of the 7-byte operand-immediate compare instruction, so
     // we add 3 to the offset to get the map address.
     Address map_address = test_instruction_address + offset_value + 3;
-    // patch the map check.
+    // Patch the map check.
     (*(reinterpret_cast<Object**>(map_address))) = value;
   }
 }
 
 
 // Defined in ic.cc.
 Object* KeyedLoadIC_Miss(Arguments args);
 
 
 void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
@@ skipping 127 matching lines @@
 
   // Do tail-call to runtime routine.
   __ TailCallRuntime(
       ExternalReference(IC_Utility(kSharedStoreIC_ExtendStorage)), 3);
 }
 
 #undef __
 
 
 } }  // namespace v8::internal