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

src/mips/builtins-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1033 matching lines @@
         Operand(ExternalReference::interpreter_dispatch_table_address(
             masm->isolate())));
 
   // Dispatch to the first bytecode handler for the function.
   __ Addu(a0, kInterpreterBytecodeArrayRegister,
           kInterpreterBytecodeOffsetRegister);
   __ lbu(a0, MemOperand(a0));
   __ Lsa(at, kInterpreterDispatchTableRegister, a0, kPointerSizeLog2);
   __ lw(at, MemOperand(at));
   __ Call(at);
+  masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
 
-  // Even though the first bytecode handler was called, we will never return.
-  __ Abort(kUnexpectedReturnFromBytecodeHandler);
+  // The return value is in v0.
+
+  // Get the arguments + reciever count.
+  __ lw(t0, MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ lw(t0, FieldMemOperand(t0, BytecodeArray::kParameterSizeOffset));
+
+  // Leave the frame (also dropping the register file).
+  __ LeaveFrame(StackFrame::JAVA_SCRIPT);
+
+  // Drop receiver + arguments and return.
+  __ Addu(sp, sp, t0);
+  __ Jump(ra);
 
   // Load debug copy of the bytecode array.
   __ bind(&load_debug_bytecode_array);
   __ lw(kInterpreterBytecodeArrayRegister,
         FieldMemOperand(debug_info, DebugInfo::kAbstractCodeIndex));
   __ Branch(&bytecode_array_loaded);
 
   // If the bytecode array is no longer present, then the underlying function
   // has been switched to a different kind of code and we heal the closure by
   // switching the code entry field over to the new code object as well.
   __ bind(&bytecode_array_not_present);
   __ LeaveFrame(StackFrame::JAVA_SCRIPT);
   __ lw(t0, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
   __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kCodeOffset));
   __ Addu(t0, t0, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ sw(t0, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
   __ RecordWriteCodeEntryField(a1, t0, t1);
   __ Jump(t0);
 }
 
-
-void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
-  // 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 and return.
-  __ lw(at, FieldMemOperand(kInterpreterBytecodeArrayRegister,
-                            BytecodeArray::kParameterSizeOffset));
-  __ Addu(sp, sp, at);
-  __ Jump(ra);
-}
-
-
 // static
 void Builtins::Generate_InterpreterPushArgsAndCallImpl(
     MacroAssembler* masm, TailCallMode tail_call_mode) {
   // ----------- S t a t e -------------
   //  -- a0 : the number of arguments (not including the receiver)
   //  -- a2 : 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.
   //  -- a1 : the target to call (can be any Object).
   // -----------------------------------
@@ skipping 12 matching lines @@
   __ push(t0);
   __ bind(&loop_check);
   __ Branch(&loop_header, gt, a2, Operand(a3));
 
   // 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 -------------
   // -- a0 : argument count (not including receiver)
   // -- a3 : new target
   // -- a1 : constructor to call
   // -- a2 : address of the first argument
   // -----------------------------------
 
   // Find the address of the last argument.
@@ skipping 10 matching lines @@
   __ lw(t1, MemOperand(a2));
   __ Addu(a2, a2, Operand(-kPointerSize));
   __ push(t1);
   __ bind(&loop_check);
   __ Branch(&loop_header, gt, a2, Operand(t0));
 
   // Call the constructor with a0, a1, and a3 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));
+  __ li(t0, Operand(masm->isolate()->builtins()->InterpreterEntryTrampoline()));
+  __ Addu(ra, t0, Operand(interpreter_entry_return_pc_offset->value() +
+                          Code::kHeaderSize - kHeapObjectTag));
 
-static void Generate_EnterBytecodeDispatch(MacroAssembler* masm) {
   // 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(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
 
   if (FLAG_debug_code) {
@@ skipping 13 matching lines @@
 
   // Dispatch to the target bytecode.
   __ Addu(a1, kInterpreterBytecodeArrayRegister,
           kInterpreterBytecodeOffsetRegister);
   __ lbu(a1, MemOperand(a1));
   __ Lsa(a1, kInterpreterDispatchTableRegister, a1, kPointerSizeLog2);
   __ lw(a1, MemOperand(a1));
   __ Jump(a1);
 }
 
-
-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.
-    __ li(a1, Operand(Smi::FromInt(static_cast<int>(type))));
-    __ push(a1);
-    __ 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.
-  __ li(ra, Operand(masm->isolate()->builtins()->InterpreterEntryTrampoline()));
-
-  Generate_EnterBytecodeDispatch(masm);
-}
-
-
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0 : argument count (preserved for callee)
   //  -- a3 : new target (preserved for callee)
   //  -- a1 : target function (preserved for callee)
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime, gotta_call_runtime_no_stack;
   Label maybe_call_runtime;
   Label try_shared;
@@ skipping 277 matching lines @@
     __ li(a0, Operand(Smi::FromInt(static_cast<int>(type))));
     __ push(a0);
     __ CallRuntime(Runtime::kNotifyDeoptimized);
   }
 
   // Get the full codegen state from the stack and untag it -> t2.
   __ lw(t2, MemOperand(sp, 0 * kPointerSize));
   __ SmiUntag(t2);
   // Switch on the state.
   Label with_tos_register, unknown_state;
-  __ Branch(&with_tos_register,
-            ne, t2, Operand(FullCodeGenerator::NO_REGISTERS));
+  __ Branch(&with_tos_register, ne, t2,
+            Operand(static_cast<int>(Deoptimizer::BailoutState::NO_REGISTERS)));
   __ Ret(USE_DELAY_SLOT);
   // Safe to fill delay slot Addu will emit one instruction.
   __ Addu(sp, sp, Operand(1 * kPointerSize));  // Remove state.
 
   __ bind(&with_tos_register);
+  DCHECK_EQ(kInterpreterAccumulatorRegister.code(), v0.code());
   __ lw(v0, MemOperand(sp, 1 * kPointerSize));
-  __ Branch(&unknown_state, ne, t2, Operand(FullCodeGenerator::TOS_REG));
+  __ Branch(&unknown_state, ne, t2,
+            Operand(static_cast<int>(Deoptimizer::BailoutState::TOS_REGISTER)));
 
   __ Ret(USE_DELAY_SLOT);
   // Safe to fill delay slot Addu will emit one instruction.
   __ Addu(sp, sp, Operand(2 * kPointerSize));  // Remove state.
 
   __ bind(&unknown_state);
   __ stop("no cases left");
 }
 
 
@@ skipping 1339 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS