[Interpreter] Remove register file register and replace with LoadParentFramePointer.

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index c6e9f445049ba7384b2db8deca0d14b0e3e35f1e..4969dc7253b871dcc70049551bbab5088382c3ab 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -1050,8 +1050,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Load accumulator, register file, bytecode offset, dispatch table into
   // registers.
   __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
-  __ add(kInterpreterRegisterFileRegister, fp,
-         Operand(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  __ add(r4, fp, Operand(InterpreterFrameConstants::kRegisterFileFromFp));
   __ mov(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ mov(kInterpreterDispatchTableRegister,
@@ -1071,12 +1070,6 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
 
 void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
-  // TODO(rmcilroy): List of things not currently dealt with here but done in
-  // fullcodegen's EmitReturnSequence.
-  //  - Supporting FLAG_trace for Runtime::TraceExit.
-  //  - Support profiler (specifically decrementing profiling_counter
-  //    appropriately and calling out to HandleInterrupts if necessary).
-
   // The return value is in accumulator, which is already in r0.
 
   // Leave the frame (also dropping the register file).
@@ -1155,18 +1148,14 @@ void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
 
 
 static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
-  // Initialize register file register and dispatch table register.
-  __ add(kInterpreterRegisterFileRegister, fp,
-         Operand(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  // Initialize the dispatch table register.
   __ mov(kInterpreterDispatchTableRegister,
          Operand(ExternalReference::interpreter_dispatch_table_address(
              masm->isolate())));
 
   // Get the bytecode array pointer from the frame.
-  __ ldr(
-      kInterpreterBytecodeArrayRegister,
-      MemOperand(kInterpreterRegisterFileRegister,
-                 InterpreterFrameConstants::kBytecodeArrayFromRegisterPointer));
+  __ ldr(kInterpreterBytecodeArrayRegister,
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
 
   if (FLAG_debug_code) {
     // Check function data field is actually a BytecodeArray object.
@@ -1179,9 +1168,7 @@ static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
 
   // Get the target bytecode offset from the frame.
   __ ldr(kInterpreterBytecodeOffsetRegister,
-         MemOperand(
-             kInterpreterRegisterFileRegister,
-             InterpreterFrameConstants::kBytecodeOffsetFromRegisterPointer));
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   // Dispatch to the target bytecode.