PPC/s390: [interpreter] Fix self-healing with preserved bytecode.

Port 4598d913

Original commit message:

    This fixes the self-healing mechanism for closures in the interpreter
    entry trampoline not that bytecode can be preserved even when baseline
    code is already available.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=chromium:638225
LOG=N

Review-Url: https://codereview.chromium.org/2265193002
Cr-Commit-Position: refs/heads/master@{#38799}

src/builtins/ppc/builtins-ppc.cc

@@ -1077,11 +1077,14 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
            FieldMemOperand(debug_info, DebugInfo::kDebugBytecodeArrayIndex));
   __ bind(&array_done);
 
+  // Check whether we should continue to use the interpreter.
+  Label switch_to_different_code_kind;
+  __ LoadP(r3, FieldMemOperand(r3, SharedFunctionInfo::kCodeOffset));
+  __ mov(ip, Operand(masm->CodeObject()));  // Self-reference to this code.
+  __ cmp(r3, ip);
+  __ bne(&switch_to_different_code_kind);
+
   // Check function data field is actually a BytecodeArray object.
-  Label bytecode_array_not_present;
-  __ CompareRoot(kInterpreterBytecodeArrayRegister,
-                 Heap::kUndefinedValueRootIndex);
-  __ beq(&bytecode_array_not_present);
 
   if (FLAG_debug_code) {
     __ TestIfSmi(kInterpreterBytecodeArrayRegister, r0);
@@ -1146,10 +1149,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r5);
   __ blr();
 
-  // 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);
   __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
   __ LoadP(r7, FieldMemOperand(r7, SharedFunctionInfo::kCodeOffset));

src/builtins/s390/builtins-s390.cc

@@ -1081,12 +1081,13 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
            FieldMemOperand(debug_info, DebugInfo::kDebugBytecodeArrayIndex));
   __ bind(&array_done);
 
-  // Check function data field is actually a BytecodeArray object.
-  Label bytecode_array_not_present;
-  __ CompareRoot(kInterpreterBytecodeArrayRegister,
-                 Heap::kUndefinedValueRootIndex);
-  __ beq(&bytecode_array_not_present);
+  // Check whether we should continue to use the interpreter.
+  Label switch_to_different_code_kind;
+  __ LoadP(r2, FieldMemOperand(r2, SharedFunctionInfo::kCodeOffset));
+  __ CmpP(r2, Operand(masm->CodeObject()));  // Self-reference to this code.
+  __ bne(&switch_to_different_code_kind);
 
+  // Check function data field is actually a BytecodeArray object.
   if (FLAG_debug_code) {
     __ TestIfSmi(kInterpreterBytecodeArrayRegister);
     __ Assert(ne, kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
@@ -1152,10 +1153,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r4);
   __ Ret();
 
-  // 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);
   __ LoadP(r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
   __ LoadP(r6, FieldMemOperand(r6, SharedFunctionInfo::kCodeOffset));