[Interpreter] Remove InterpreterExitTrampoline and replace with returning to the entry trampoline.

src/arm64/builtins-arm64.cc

Index: src/arm64/builtins-arm64.cc
diff --git a/src/arm64/builtins-arm64.cc b/src/arm64/builtins-arm64.cc
index 81f01188bd2e8e3ac194a67224450c4234f1c28d..dc293729ae4ce5ced4c262246444118acaefd761 100644
--- a/src/arm64/builtins-arm64.cc
+++ b/src/arm64/builtins-arm64.cc
@@ -963,7 +963,6 @@ void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
   Generate_JSEntryTrampolineHelper(masm, true);
 }
 
-
 // Generate code for entering a JS function with the interpreter.
 // On entry to the function the receiver and arguments have been pushed on the
 // stack left to right.  The actual argument count matches the formal parameter
@@ -1062,9 +1061,20 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Mov(x1, Operand(x1, LSL, kPointerSizeLog2));
   __ Ldr(ip0, MemOperand(kInterpreterDispatchTableRegister, x1));
   __ Call(ip0);
+  masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
+
+  // The return value is in x0.
+
+  // Get the arguments + reciever count.
+  __ ldr(x1, MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ Ldr(w1, FieldMemOperand(x1, BytecodeArray::kParameterSizeOffset));
+
+  // Leave the frame (also dropping the register file).
+  __ LeaveFrame(StackFrame::JAVA_SCRIPT);
 
-  // Even though the first bytecode handler was called, we will never return.
-  __ Abort(kUnexpectedReturnFromBytecodeHandler);
+  // Drop receiver + arguments and return.
+  __ Drop(x1, 1);
+  __ Ret();
 
   // Load debug copy of the bytecode array.
   __ Bind(&load_debug_bytecode_array);
@@ -1085,22 +1095,87 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Jump(x7);
 }
 
+// static
+void Builtins::Generate_InterpreterPushArgsAndCallImpl(
+    MacroAssembler* masm, TailCallMode tail_call_mode) {
+  // ----------- S t a t e -------------
+  //  -- x0 : the number of arguments (not including the receiver)
+  //  -- x2 : the address of the first argument to be pushed. Subsequent
+  //          arguments should be consecutive above this, in the same order as
+  //          they are to be pushed onto the stack.
+  //  -- x1 : the target to call (can be any Object).
+  // -----------------------------------
 
-void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
-  // The return value is in accumulator, which is already in x0.
+  // Find the address of the last argument.
+  __ add(x3, x0, Operand(1));  // Add one for receiver.
+  __ lsl(x3, x3, kPointerSizeLog2);
+  __ sub(x4, x2, x3);
 
-  // Leave the frame (also dropping the register file).
-  __ LeaveFrame(StackFrame::JAVA_SCRIPT);
+  // Push the arguments.
+  Label loop_header, loop_check;
+  __ Mov(x5, jssp);
+  __ Claim(x3, 1);
+  __ B(&loop_check);
+  __ Bind(&loop_header);
+  // TODO(rmcilroy): Push two at a time once we ensure we keep stack aligned.
+  __ Ldr(x3, MemOperand(x2, -kPointerSize, PostIndex));
+  __ Str(x3, MemOperand(x5, -kPointerSize, PreIndex));
+  __ Bind(&loop_check);
+  __ Cmp(x2, x4);
+  __ B(gt, &loop_header);
 
-  // Drop receiver + arguments and return.
-  __ Ldr(w1, FieldMemOperand(kInterpreterBytecodeArrayRegister,
-                             BytecodeArray::kParameterSizeOffset));
-  __ Drop(x1, 1);
-  __ Ret();
+  // Call the target.
+  __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny,
+                                            tail_call_mode),
+          RelocInfo::CODE_TARGET);
 }
 
+// static
+void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  // -- x0 : argument count (not including receiver)
+  // -- x3 : new target
+  // -- x1 : constructor to call
+  // -- x2 : address of the first argument
+  // -----------------------------------
+
+  // Find the address of the last argument.
+  __ add(x5, x0, Operand(1));  // Add one for receiver (to be constructed).
+  __ lsl(x5, x5, kPointerSizeLog2);
+
+  // Set stack pointer and where to stop.
+  __ Mov(x6, jssp);
+  __ Claim(x5, 1);
+  __ sub(x4, x6, x5);
+
+  // Push a slot for the receiver.
+  __ Str(xzr, MemOperand(x6, -kPointerSize, PreIndex));
+
+  Label loop_header, loop_check;
+  // Push the arguments.
+  __ B(&loop_check);
+  __ Bind(&loop_header);
+  // TODO(rmcilroy): Push two at a time once we ensure we keep stack aligned.
+  __ Ldr(x5, MemOperand(x2, -kPointerSize, PostIndex));
+  __ Str(x5, MemOperand(x6, -kPointerSize, PreIndex));
+  __ Bind(&loop_check);
+  __ Cmp(x6, x4);
+  __ B(gt, &loop_header);
+
+  // Call the constructor with x0, x1, and x3 unmodified.
+  __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
+}
+
+void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+  // Set the return address to the correct point in the interpreter entry
+  // trampoline.
+  Smi* interpreter_entry_return_pc_offset(
+      masm->isolate()->heap()->interpreter_entry_return_pc_offset());
+  DCHECK_NE(interpreter_entry_return_pc_offset, Smi::FromInt(0));
+  __ LoadObject(x1, masm->isolate()->builtins()->InterpreterEntryTrampoline());
+  __ Add(lr, x1, Operand(interpreter_entry_return_pc_offset->value() +
+                         Code::kHeaderSize - kHeapObjectTag));
 
-static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
   // Initialize the dispatch table register.
   __ Mov(kInterpreterDispatchTableRegister,
          Operand(ExternalReference::interpreter_dispatch_table_address(
@@ -1132,55 +1207,6 @@ static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
   __ Jump(ip0);
 }
 
-
-static void Generate_InterpreterNotifyDeoptimizedHelper(
-    MacroAssembler* masm, Deoptimizer::BailoutType type) {
-  // Enter an internal frame.
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-
-    // Pass the deoptimization type to the runtime system.
-    __ Mov(x1, Operand(Smi::FromInt(static_cast<int>(type))));
-    __ Push(x1);
-    __ CallRuntime(Runtime::kNotifyDeoptimized);
-    // Tear down internal frame.
-  }
-
-  // Drop state (we don't use these for interpreter deopts) and and pop the
-  // accumulator value into the accumulator register.
-  __ Drop(1);
-  __ Pop(kInterpreterAccumulatorRegister);
-
-  // Enter the bytecode dispatch.
-  Generate_EnterBytecodeDispatch(masm);
-}
-
-
-void Builtins::Generate_InterpreterNotifyDeoptimized(MacroAssembler* masm) {
-  Generate_InterpreterNotifyDeoptimizedHelper(masm, Deoptimizer::EAGER);
-}
-
-
-void Builtins::Generate_InterpreterNotifySoftDeoptimized(MacroAssembler* masm) {
-  Generate_InterpreterNotifyDeoptimizedHelper(masm, Deoptimizer::SOFT);
-}
-
-
-void Builtins::Generate_InterpreterNotifyLazyDeoptimized(MacroAssembler* masm) {
-  Generate_InterpreterNotifyDeoptimizedHelper(masm, Deoptimizer::LAZY);
-}
-
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
-  // Set the address of the interpreter entry trampoline as a return address.
-  // This simulates the initial call to bytecode handlers in interpreter entry
-  // trampoline. The return will never actually be taken, but our stack walker
-  // uses this address to determine whether a frame is interpreted.
-  __ LoadObject(lr, masm->isolate()->builtins()->InterpreterEntryTrampoline());
-
-  Generate_EnterBytecodeDispatch(masm);
-}
-
-
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- x0 : argument count (preserved for callee)
@@ -1469,15 +1495,19 @@ static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
 
   // Switch on the state.
   Label with_tos_register, unknown_state;
-  __ CompareAndBranch(
-      state, FullCodeGenerator::NO_REGISTERS, ne, &with_tos_register);
+  __ CompareAndBranch(state,
+                      static_cast<int>(Deoptimizer::BailoutState::NO_REGISTERS),
+                      ne, &with_tos_register);
   __ Drop(1);  // Remove state.
   __ Ret();
 
   __ Bind(&with_tos_register);
   // Reload TOS register.
+  DCHECK_EQ(kInterpreterAccumulatorRegister.code(), x0.code());
   __ Peek(x0, kPointerSize);
-  __ CompareAndBranch(state, FullCodeGenerator::TOS_REG, ne, &unknown_state);
+  __ CompareAndBranch(state,
+                      static_cast<int>(Deoptimizer::BailoutState::TOS_REGISTER),
+                      ne, &unknown_state);
   __ Drop(2);  // Remove state and TOS.
   __ Ret();
 
@@ -2678,79 +2708,6 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
           RelocInfo::CODE_TARGET);
 }
 
-
-// static
-void Builtins::Generate_InterpreterPushArgsAndCallImpl(
-    MacroAssembler* masm, TailCallMode tail_call_mode) {
-  // ----------- S t a t e -------------
-  //  -- x0 : the number of arguments (not including the receiver)
-  //  -- x2 : the address of the first argument to be pushed. Subsequent
-  //          arguments should be consecutive above this, in the same order as
-  //          they are to be pushed onto the stack.
-  //  -- x1 : the target to call (can be any Object).
-  // -----------------------------------
-
-  // Find the address of the last argument.
-  __ add(x3, x0, Operand(1));  // Add one for receiver.
-  __ lsl(x3, x3, kPointerSizeLog2);
-  __ sub(x4, x2, x3);
-
-  // Push the arguments.
-  Label loop_header, loop_check;
-  __ Mov(x5, jssp);
-  __ Claim(x3, 1);
-  __ B(&loop_check);
-  __ Bind(&loop_header);
-  // TODO(rmcilroy): Push two at a time once we ensure we keep stack aligned.
-  __ Ldr(x3, MemOperand(x2, -kPointerSize, PostIndex));
-  __ Str(x3, MemOperand(x5, -kPointerSize, PreIndex));
-  __ Bind(&loop_check);
-  __ Cmp(x2, x4);
-  __ B(gt, &loop_header);
-
-  // Call the target.
-  __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny,
-                                            tail_call_mode),
-          RelocInfo::CODE_TARGET);
-}
-
-
-// static
-void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  // -- x0 : argument count (not including receiver)
-  // -- x3 : new target
-  // -- x1 : constructor to call
-  // -- x2 : address of the first argument
-  // -----------------------------------
-
-  // Find the address of the last argument.
-  __ add(x5, x0, Operand(1));  // Add one for receiver (to be constructed).
-  __ lsl(x5, x5, kPointerSizeLog2);
-
-  // Set stack pointer and where to stop.
-  __ Mov(x6, jssp);
-  __ Claim(x5, 1);
-  __ sub(x4, x6, x5);
-
-  // Push a slot for the receiver.
-  __ Str(xzr, MemOperand(x6, -kPointerSize, PreIndex));
-
-  Label loop_header, loop_check;
-  // Push the arguments.
-  __ B(&loop_check);
-  __ Bind(&loop_header);
-  // TODO(rmcilroy): Push two at a time once we ensure we keep stack aligned.
-  __ Ldr(x5, MemOperand(x2, -kPointerSize, PostIndex));
-  __ Str(x5, MemOperand(x6, -kPointerSize, PreIndex));
-  __ Bind(&loop_check);
-  __ Cmp(x6, x4);
-  __ B(gt, &loop_header);
-
-  // Call the constructor with x0, x1, and x3 unmodified.
-  __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
-}
-
 // static
 void Builtins::Generate_AllocateInNewSpace(MacroAssembler* masm) {
   ASM_LOCATION("Builtins::Generate_AllocateInNewSpace");