/*

 * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// This file contains the platform-independent parts

// of the abstract interpreter and the abstract interpreter generator.

// Organization of the interpreter(s). There exists two different interpreters in hotpot

// an assembly language version (aka template interpreter) and a high level language version

// (aka c++ interpreter). Th division of labor is as follows:

// Template Interpreter          C++ Interpreter        Functionality

//

// templateTable*                bytecodeInterpreter*   actual interpretation of bytecodes

//

// templateInterpreter*          cppInterpreter*        generation of assembly code that creates

//                                                      and manages interpreter runtime frames.

//                                                      Also code for populating interpreter

//                                                      frames created during deoptimization.

//

// For both template and c++ interpreter. There are common files for aspects of the interpreter

// that are generic to both interpreters. This is the layout:

//

// abstractInterpreter.hpp: generic description of the interpreter.

// interpreter*:            generic frame creation and handling.

//

//------------------------------------------------------------------------------------------------------------------------

// The C++ interface to the bytecode interpreter(s).

class AbstractInterpreter: AllStatic {

  friend class VMStructs;

  friend class Interpreter;

  friend class CppInterpreterGenerator;

 public:

  enum MethodKind {

    zerolocals,                                                 // method needs locals initialization

    zerolocals_synchronized,                                    // method needs locals initialization & is synchronized

    native,                                                     // native method

    native_synchronized,                                        // native method & is synchronized

    empty,                                                      // empty method (code: _return)

    accessor,                                                   // accessor method (code: _aload_0, _getfield, _(a|i)return)

    abstract,                                                   // abstract method (throws an AbstractMethodException)

    method_handle,                                              // java.dyn.MethodHandles::invoke

    java_lang_math_sin,                                         // implementation of java.lang.Math.sin   (x)

    java_lang_math_cos,                                         // implementation of java.lang.Math.cos   (x)

    java_lang_math_tan,                                         // implementation of java.lang.Math.tan   (x)

    java_lang_math_abs,                                         // implementation of java.lang.Math.abs   (x)

    java_lang_math_sqrt,                                        // implementation of java.lang.Math.sqrt  (x)

    java_lang_math_log,                                         // implementation of java.lang.Math.log   (x)

    java_lang_math_log10,                                       // implementation of java.lang.Math.log10 (x)

    number_of_method_entries,

    invalid = -1

  };

  enum SomeConstants {

    number_of_result_handlers = 10                              // number of result handlers for native calls

  };

 protected:

  static StubQueue* _code;                                      // the interpreter code (codelets)

  static bool       _notice_safepoints;                         // true if safepoints are activated

  static address    _native_entry_begin;                        // Region for native entry code

  static address    _native_entry_end;

  // method entry points

  static address    _entry_table[number_of_method_entries];     // entry points for a given method

  static address    _native_abi_to_tosca[number_of_result_handlers];  // for native method result handlers

  static address    _slow_signature_handler;                              // the native method generic (slow) signature handler

  static address    _rethrow_exception_entry;                   // rethrows an activation in previous frame

  friend class      AbstractInterpreterGenerator;

  friend class              InterpreterGenerator;

  friend class      InterpreterMacroAssembler;

 public:

  // Initialization/debugging

  static void       initialize();

  static StubQueue* code()                                      { return _code; }

  // Method activation

  static MethodKind method_kind(methodHandle m);

  static address    entry_for_kind(MethodKind k)                { assert(0 <= k && k < number_of_method_entries, "illegal kind"); return _entry_table[k]; }

  static address    entry_for_method(methodHandle m)            { return _entry_table[method_kind(m)]; }

  static void       print_method_kind(MethodKind kind)          PRODUCT_RETURN;

  // Runtime support

  // length = invoke bytecode length (to advance to next bytecode)

  static address    deopt_entry   (TosState state, int length) { ShouldNotReachHere(); return NULL; }

  static address    return_entry  (TosState state, int length) { ShouldNotReachHere(); return NULL; }

  static address    rethrow_exception_entry()                   { return _rethrow_exception_entry; }

  // Activation size in words for a method that is just being called.

  // Parameters haven't been pushed so count them too.

  static int        size_top_interpreter_activation(methodOop method);

  // Deoptimization support

  static address    continuation_for(methodOop method,

                                     address bcp,

                                     int callee_parameters,

                                     bool is_top_frame,

                                     bool& use_next_mdp);

  // share implementation of size_activation and layout_activation:

  static int        size_activation(methodOop method,

                                    int temps,

                                    int popframe_args,

                                    int monitors,

                                    int callee_params,

                                    int callee_locals,

                                    bool is_top_frame);

  static int       layout_activation(methodOop method,

                                      int temps,

                                      int popframe_args,

                                      int monitors,

                                      int callee_params,

                                      int callee_locals,

                                      frame* caller,

                                      frame* interpreter_frame,

                                      bool is_top_frame);

  // Runtime support

  static bool       is_not_reached(                       methodHandle method, int bci);

  // Safepoint support

  static void       notice_safepoints()                         { ShouldNotReachHere(); } // stops the thread when reaching a safepoint

  static void       ignore_safepoints()                         { ShouldNotReachHere(); } // ignores safepoints

  // Support for native calls

  static address    slow_signature_handler()                    { return _slow_signature_handler; }

  static address    result_handler(BasicType type)              { return _native_abi_to_tosca[BasicType_as_index(type)]; }

  static int        BasicType_as_index(BasicType type);         // computes index into result_handler_by_index table

  static bool       in_native_entry(address pc)                 { return _native_entry_begin <= pc && pc < _native_entry_end; }

  // Debugging/printing

  static void       print();                                    // prints the interpreter code

  // Support for Tagged Stacks

  //

  // Tags are stored on the Java Expression stack above the value:

  //

  //  tag

  //  value

  //

  // For double values:

  //

  //  tag2

  //  high word

  //  tag1

  //  low word

 public:

  static int stackElementWords()   { return TaggedStackInterpreter ? 2 : 1; }

  static int stackElementSize()    { return stackElementWords()*wordSize; }

  static int logStackElementSize() { return

                 TaggedStackInterpreter? LogBytesPerWord+1 : LogBytesPerWord; }

  // Tag is at pointer, value is one below for a stack growing down

  // (or above for stack growing up)

  static int  value_offset_in_bytes()  {

    return TaggedStackInterpreter ?

      frame::interpreter_frame_expression_stack_direction() * wordSize : 0;

  }

  static int  tag_offset_in_bytes()    {

    assert(TaggedStackInterpreter, "should not call this");

    return 0;

  }

  // Tagged Locals

  // Locals are stored relative to Llocals:

  //

  // tag    <- Llocals[n]

  // value

  //

  // Category 2 types are indexed as:

  //

  // tag    <- Llocals[-n]

  // high word

  // tag    <- Llocals[-n+1]

  // low word

  //

  // Local values relative to locals[n]

  static int  local_offset_in_bytes(int n) {

    return ((frame::interpreter_frame_expression_stack_direction() * n) *

            stackElementSize()) + value_offset_in_bytes();

  }

  static int  local_tag_offset_in_bytes(int n) {

    assert(TaggedStackInterpreter, "should not call this");

    return ((frame::interpreter_frame_expression_stack_direction() * n) *

            stackElementSize()) + tag_offset_in_bytes();

  }

};

//------------------------------------------------------------------------------------------------------------------------

// The interpreter generator.

class Template;

class AbstractInterpreterGenerator: public StackObj {

 protected:

  InterpreterMacroAssembler* _masm;

  // shared code sequences

  // Converter for native abi result to tosca result

  address generate_result_handler_for(BasicType type);

  address generate_slow_signature_handler();

  // entry point generator

  address generate_method_entry(AbstractInterpreter::MethodKind kind);

  void bang_stack_shadow_pages(bool native_call);

  void generate_all();

 public:

  AbstractInterpreterGenerator(StubQueue* _code);

};