[interpreter] Fix self-healing with preserved bytecode.

src/builtins/mips/builtins-mips.cc

Index: src/builtins/mips/builtins-mips.cc
diff --git a/src/builtins/mips/builtins-mips.cc b/src/builtins/mips/builtins-mips.cc
index bd0e7e252da8726bdc454d895334cc9e9fc3931b..003eeb22e01db4b13bbb10e14380944083d4bc36 100644
--- a/src/builtins/mips/builtins-mips.cc
+++ b/src/builtins/mips/builtins-mips.cc
@@ -1045,10 +1045,13 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
         FieldMemOperand(a0, SharedFunctionInfo::kFunctionDataOffset));
   __ bind(&bytecode_array_loaded);
 
+  // Check whether we should continue to use the interpreter.
+  Label switch_to_different_code_kind;
+  __ lw(a0, FieldMemOperand(a0, SharedFunctionInfo::kCodeOffset));
+  __ Branch(&switch_to_different_code_kind, ne, a0,
+            Operand(masm->CodeObject()));  // Self-reference to this code.
+
   // Check function data field is actually a BytecodeArray object.
-  Label bytecode_array_not_present;
-  __ JumpIfRoot(kInterpreterBytecodeArrayRegister,
-                Heap::kUndefinedValueRootIndex, &bytecode_array_not_present);
   if (FLAG_debug_code) {
     __ SmiTst(kInterpreterBytecodeArrayRegister, t0);
     __ Assert(ne, kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry, t0,
@@ -1119,10 +1122,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
         FieldMemOperand(debug_info, DebugInfo::kDebugBytecodeArrayIndex));
   __ Branch(&bytecode_array_loaded);
 
-  // If the bytecode array is no longer present, then the underlying function
-  // has been switched to a different kind of code and we heal the closure by
-  // switching the code entry field over to the new code object as well.
-  __ bind(&bytecode_array_not_present);
+  // If the shared code is no longer this entry trampoline, then the underlying
+  // function has been switched to a different kind of code and we heal the
+  // closure by switching the code entry field over to the new code as well.
+  __ bind(&switch_to_different_code_kind);
   __ LeaveFrame(StackFrame::JAVA_SCRIPT);
   __ lw(t0, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
   __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kCodeOffset));