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

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index 693b29d295527a4f40c97919a548e6c5c8b4bb0a..b7fedf9bee99017e354bb85b8970a98e8a86a4d8 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1039,8 +1039,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
   // Load bytecode offset and dispatch table into registers.
   __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
-  __ Addu(kInterpreterRegisterFileRegister, fp,
-          Operand(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  __ Addu(t3, fp, Operand(InterpreterFrameConstants::kRegisterFileFromFp));
   __ li(kInterpreterBytecodeOffsetRegister,
         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ li(kInterpreterDispatchTableRegister,
@@ -1067,12 +1066,6 @@ 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 v0.
 
   // Leave the frame (also dropping the register file).
@@ -1151,18 +1144,14 @@ void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
 
 
 static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
-  // Initialize register file register and dispatch table register.
-  __ Addu(kInterpreterRegisterFileRegister, fp,
-          Operand(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  // Initialize the dispatch table register.
   __ li(kInterpreterDispatchTableRegister,
         Operand(ExternalReference::interpreter_dispatch_table_address(
             masm->isolate())));
 
   // Get the bytecode array pointer from the frame.
-  __ lw(
-      kInterpreterBytecodeArrayRegister,
-      MemOperand(kInterpreterRegisterFileRegister,
-                 InterpreterFrameConstants::kBytecodeArrayFromRegisterPointer));
+  __ lw(kInterpreterBytecodeArrayRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
 
   if (FLAG_debug_code) {
     // Check function data field is actually a BytecodeArray object.
@@ -1176,9 +1165,7 @@ static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
 
   // Get the target bytecode offset from the frame.
   __ lw(kInterpreterBytecodeOffsetRegister,
-        MemOperand(
-            kInterpreterRegisterFileRegister,
-            InterpreterFrameConstants::kBytecodeOffsetFromRegisterPointer));
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   // Dispatch to the target bytecode.