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

Port 623ad7de

Original commit message:

    Removes the register file machine register from the interpreter and
    replaces it will loads from the parent frame pointer. As part of this
    change the raw operand values for register values changes to enable the
    interpreter to keep using the operand value as the offset from the
    parent frame pointer.

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

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1901763004

Cr-Commit-Position: refs/heads/master@{#35637}

src/ppc/builtins-ppc.cc

@@ -1060,8 +1060,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Load accumulator, register file, bytecode offset, dispatch table into
   // registers.
   __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
-  __ addi(kInterpreterRegisterFileRegister, fp,
-          Operand(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  __ addi(r7, fp, Operand(InterpreterFrameConstants::kRegisterFileFromFp));
   __ mov(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ mov(kInterpreterDispatchTableRegister,
@@ -1081,12 +1080,6 @@ 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 r3.
 
   // Leave the frame (also dropping the register file).
@@ -1162,18 +1155,14 @@ void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
 
 
 static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
-  // Initialize register file register and dispatch table register.
-  __ addi(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.
-  __ LoadP(
-      kInterpreterBytecodeArrayRegister,
-      MemOperand(kInterpreterRegisterFileRegister,
-                 InterpreterFrameConstants::kBytecodeArrayFromRegisterPointer));
+  __ LoadP(kInterpreterBytecodeArrayRegister,
+          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
 
   if (FLAG_debug_code) {
     // Check function data field is actually a BytecodeArray object.
@@ -1186,9 +1175,7 @@ static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
 
   // Get the target bytecode offset from the frame.
   __ LoadP(kInterpreterBytecodeOffsetRegister,
-           MemOperand(
-               kInterpreterRegisterFileRegister,
-               InterpreterFrameConstants::kBytecodeOffsetFromRegisterPointer));
+          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   // Dispatch to the target bytecode.

src/ppc/interface-descriptors-ppc.cc

@@ -373,9 +373,8 @@ void ApiCallbackDescriptorBase::InitializePlatformSpecific(
 void InterpreterDispatchDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterRegisterFileRegister,
-      kInterpreterBytecodeOffsetRegister, kInterpreterBytecodeArrayRegister,
-      kInterpreterDispatchTableRegister};
+  kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+  kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 

src/ppc/macro-assembler-ppc.h

@@ -20,7 +20,6 @@ const Register kReturnRegister2 = {Register::kCode_r5};
 const Register kJSFunctionRegister = {Register::kCode_r4};
 const Register kContextRegister = {Register::kCode_r30};
 const Register kInterpreterAccumulatorRegister = {Register::kCode_r3};
-const Register kInterpreterRegisterFileRegister = {Register::kCode_r14};
 const Register kInterpreterBytecodeOffsetRegister = {Register::kCode_r15};
 const Register kInterpreterBytecodeArrayRegister = {Register::kCode_r16};
 const Register kInterpreterDispatchTableRegister = {Register::kCode_r17};