[interpreter]: Changes to interpreter builtins for accumulator and register file registers.

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 e27199a904f9adc655c7c3eace7b5f5e15293130..b8eec2d81eee7dae9f794564193fb06c0c646b52 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -920,14 +920,15 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     __ bind(&ok);
 
     // If ok, push undefined as the initial value for all register file entries.
-    // Note: there should always be at least one stack slot for the return
-    // register in the register file.
     Label loop_header;
+    Label loop_check;
     __ LoadRoot(t1, Heap::kUndefinedValueRootIndex);
+    __ Branch(&loop_check);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
     __ push(t1);
     // Continue loop if not done.
+    __ bind(&loop_check);
     __ Subu(t0, t0, Operand(kPointerSize));
     __ Branch(&loop_header, ge, t0, Operand(zero_reg));
   }
@@ -963,6 +964,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   }
 
   // Load bytecode offset and dispatch table into registers.
+  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ Subu(
+      kInterpreterRegisterFileRegister, fp,
+      Operand(kPointerSize + StandardFrameConstants::kFixedFrameSizeFromFp));
   __ li(kInterpreterBytecodeOffsetRegister,
         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ LoadRoot(kInterpreterDispatchTableRegister,
@@ -980,7 +985,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // TODO(rmcilroy): Make dispatch table point to code entrys to avoid untagging
   // and header removal.
   __ Addu(at, at, Operand(Code::kHeaderSize - kHeapObjectTag));
-  __ Jump(at);
+  __ Call(at);
 }
 
 
@@ -991,9 +996,8 @@ void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
   //  - Support profiler (specifically decrementing profiling_counter
   //    appropriately and calling out to HandleInterrupts if necessary).
 
-  // Load return value into v0.
-  __ lw(v0, MemOperand(fp, -kPointerSize -
-                               StandardFrameConstants::kFixedFrameSizeFromFp));
+  // The return value is in accumulator, which is already in v0.
+
   // Leave the frame (also dropping the register file).
   __ LeaveFrame(StackFrame::JAVA_SCRIPT);
   // Drop receiver + arguments.