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

 *

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 * 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.

 *

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 */

// 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;

  static bool       can_be_compiled(methodHandle m);

  // 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

  // Compute the entry address for continuation after

  static address deopt_continue_after_entry(methodOop method,

                                            address bcp,

                                            int callee_parameters,

                                            bool is_top_frame);

  // Compute the entry address for reexecution

  static address deopt_reexecute_entry(methodOop method, address bcp);

  // Deoptimization should reexecute this bytecode

  static bool    bytecode_should_reexecute(Bytecodes::Code code);

  // 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

 public:

  // Interpreter helpers

  const static int stackElementWords   = 1;

  const static int stackElementSize    = stackElementWords * wordSize;

  const static int logStackElementSize = LogBytesPerWord;

  // Local values relative to locals[n]

  static int  local_offset_in_bytes(int n) {

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

  }

  // access to stacked values according to type:

  static oop* oop_addr_in_slot(intptr_t* slot_addr) {

    return (oop*) slot_addr;

  }

  static jint* int_addr_in_slot(intptr_t* slot_addr) {

    if ((int) sizeof(jint) < wordSize && !Bytes::is_Java_byte_ordering_different())

      // big-endian LP64

      return (jint*)(slot_addr + 1) - 1;

    else

      return (jint*) slot_addr;

  }

  static jlong long_in_slot(intptr_t* slot_addr) {

    if (sizeof(intptr_t) >= sizeof(jlong)) {

      return *(jlong*) slot_addr;

    } else {

      return Bytes::get_native_u8((address)slot_addr);

    }

  }

  static void set_long_in_slot(intptr_t* slot_addr, jlong value) {

    if (sizeof(intptr_t) >= sizeof(jlong)) {

      *(jlong*) slot_addr = value;

    } else {

      Bytes::put_native_u8((address)slot_addr, value);

    }

  }

  static void get_jvalue_in_slot(intptr_t* slot_addr, BasicType type, jvalue* value) {

    switch (type) {

    case T_BOOLEAN: value->z = *int_addr_in_slot(slot_addr);            break;

    case T_CHAR:    value->c = *int_addr_in_slot(slot_addr);            break;

    case T_BYTE:    value->b = *int_addr_in_slot(slot_addr);            break;

    case T_SHORT:   value->s = *int_addr_in_slot(slot_addr);            break;

    case T_INT:     value->i = *int_addr_in_slot(slot_addr);            break;

    case T_LONG:    value->j = long_in_slot(slot_addr);                 break;

    case T_FLOAT:   value->f = *(jfloat*)int_addr_in_slot(slot_addr);   break;

    case T_DOUBLE:  value->d = jdouble_cast(long_in_slot(slot_addr));   break;

    case T_OBJECT:  value->l = (jobject)*oop_addr_in_slot(slot_addr);   break;

    default:        ShouldNotReachHere();

    }

  }

  static void set_jvalue_in_slot(intptr_t* slot_addr, BasicType type, jvalue* value) {

    switch (type) {

    case T_BOOLEAN: *int_addr_in_slot(slot_addr) = (value->z != 0);     break;

    case T_CHAR:    *int_addr_in_slot(slot_addr) = value->c;            break;

    case T_BYTE:    *int_addr_in_slot(slot_addr) = value->b;            break;

    case T_SHORT:   *int_addr_in_slot(slot_addr) = value->s;            break;

    case T_INT:     *int_addr_in_slot(slot_addr) = value->i;            break;

    case T_LONG:    set_long_in_slot(slot_addr, value->j);              break;

    case T_FLOAT:   *(jfloat*)int_addr_in_slot(slot_addr) = value->f;   break;

    case T_DOUBLE:  set_long_in_slot(slot_addr, jlong_cast(value->d));  break;

    case T_OBJECT:  *oop_addr_in_slot(slot_addr) = (oop) value->l;      break;

    default:        ShouldNotReachHere();

    }

  }

};

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

// 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);

};