/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "interpreter/interpreter.hpp"

#include "interpreter/interpreterRuntime.hpp"

#include "interpreter/interp_masm.hpp"

#include "interpreter/templateInterpreter.hpp"

#include "interpreter/templateInterpreterGenerator.hpp"

#include "interpreter/templateTable.hpp"

#include "logging/log.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/safepoint.hpp"

#include "runtime/timerTrace.hpp"

#include "utilities/copy.hpp"

#ifndef CC_INTERP

# define __ _masm->

void TemplateInterpreter::initialize() {

  if (_code != NULL) return;

  // assertions

  assert((int)Bytecodes::number_of_codes <= (int)DispatchTable::length,

         "dispatch table too small");

  AbstractInterpreter::initialize();

  TemplateTable::initialize();

  // generate interpreter

  { ResourceMark rm;

    TraceTime timer("Interpreter generation", TRACETIME_LOG(Info, startuptime));

    int code_size = InterpreterCodeSize;

    NOT_PRODUCT(code_size *= 4;)  // debug uses extra interpreter code space

    _code = new StubQueue(new InterpreterCodeletInterface, code_size, NULL,

                          "Interpreter");

    TemplateInterpreterGenerator g(_code);

    // Free the unused memory not occupied by the interpreter and the stubs

    _code->deallocate_unused_tail();

  }

  if (PrintInterpreter) {

    ResourceMark rm;

    print();

  }

  // initialize dispatch table

  _active_table = _normal_table;

}

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

// Implementation of EntryPoint

EntryPoint::EntryPoint() {

  assert(number_of_states == 10, "check the code below");

  _entry[btos] = NULL;

  _entry[ztos] = NULL;

  _entry[ctos] = NULL;

  _entry[stos] = NULL;

  _entry[atos] = NULL;

  _entry[itos] = NULL;

  _entry[ltos] = NULL;

  _entry[ftos] = NULL;

  _entry[dtos] = NULL;

  _entry[vtos] = NULL;

}

EntryPoint::EntryPoint(address bentry, address zentry, address centry, address sentry, address aentry, address ientry, address lentry, address fentry, address dentry, address ventry) {

  assert(number_of_states == 10, "check the code below");

  _entry[btos] = bentry;

  _entry[ztos] = zentry;

  _entry[ctos] = centry;

  _entry[stos] = sentry;

  _entry[atos] = aentry;

  _entry[itos] = ientry;

  _entry[ltos] = lentry;

  _entry[ftos] = fentry;

  _entry[dtos] = dentry;

  _entry[vtos] = ventry;

}

void EntryPoint::set_entry(TosState state, address entry) {

  assert(0 <= state && state < number_of_states, "state out of bounds");

  _entry[state] = entry;

}

address EntryPoint::entry(TosState state) const {

  assert(0 <= state && state < number_of_states, "state out of bounds");

  return _entry[state];

}

void EntryPoint::print() {

  tty->print("[");

  for (int i = 0; i < number_of_states; i++) {

    if (i > 0) tty->print(", ");

    tty->print(INTPTR_FORMAT, p2i(_entry[i]));

  }

  tty->print("]");

}

bool EntryPoint::operator == (const EntryPoint& y) {

  int i = number_of_states;

  while (i-- > 0) {

    if (_entry[i] != y._entry[i]) return false;

  }

  return true;

}

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

// Implementation of DispatchTable

EntryPoint DispatchTable::entry(int i) const {

  assert(0 <= i && i < length, "index out of bounds");

  return

    EntryPoint(

      _table[btos][i],

      _table[ztos][i],

      _table[ctos][i],

      _table[stos][i],

      _table[atos][i],

      _table[itos][i],

      _table[ltos][i],

      _table[ftos][i],

      _table[dtos][i],

      _table[vtos][i]

    );

}

void DispatchTable::set_entry(int i, EntryPoint& entry) {

  assert(0 <= i && i < length, "index out of bounds");

  assert(number_of_states == 10, "check the code below");

  _table[btos][i] = entry.entry(btos);

  _table[ztos][i] = entry.entry(ztos);

  _table[ctos][i] = entry.entry(ctos);

  _table[stos][i] = entry.entry(stos);

  _table[atos][i] = entry.entry(atos);

  _table[itos][i] = entry.entry(itos);

  _table[ltos][i] = entry.entry(ltos);

  _table[ftos][i] = entry.entry(ftos);

  _table[dtos][i] = entry.entry(dtos);

  _table[vtos][i] = entry.entry(vtos);

}

bool DispatchTable::operator == (DispatchTable& y) {

  int i = length;

  while (i-- > 0) {

    EntryPoint t = y.entry(i); // for compiler compatibility (BugId 4150096)

    if (!(entry(i) == t)) return false;

  }

  return true;

}

address    TemplateInterpreter::_remove_activation_entry                    = NULL;

address    TemplateInterpreter::_remove_activation_preserving_args_entry    = NULL;

address    TemplateInterpreter::_throw_ArrayIndexOutOfBoundsException_entry = NULL;

address    TemplateInterpreter::_throw_ArrayStoreException_entry            = NULL;

address    TemplateInterpreter::_throw_ArithmeticException_entry            = NULL;

address    TemplateInterpreter::_throw_ClassCastException_entry             = NULL;

address    TemplateInterpreter::_throw_NullPointerException_entry           = NULL;

address    TemplateInterpreter::_throw_StackOverflowError_entry             = NULL;

address    TemplateInterpreter::_throw_exception_entry                      = NULL;

#ifndef PRODUCT

EntryPoint TemplateInterpreter::_trace_code;

#endif // !PRODUCT

EntryPoint TemplateInterpreter::_return_entry[TemplateInterpreter::number_of_return_entries];

EntryPoint TemplateInterpreter::_earlyret_entry;

EntryPoint TemplateInterpreter::_deopt_entry [TemplateInterpreter::number_of_deopt_entries ];

address    TemplateInterpreter::_deopt_reexecute_return_entry;

EntryPoint TemplateInterpreter::_safept_entry;

address TemplateInterpreter::_invoke_return_entry[TemplateInterpreter::number_of_return_addrs];

address TemplateInterpreter::_invokeinterface_return_entry[TemplateInterpreter::number_of_return_addrs];

address TemplateInterpreter::_invokedynamic_return_entry[TemplateInterpreter::number_of_return_addrs];

DispatchTable TemplateInterpreter::_active_table;

DispatchTable TemplateInterpreter::_normal_table;

DispatchTable TemplateInterpreter::_safept_table;

address    TemplateInterpreter::_wentry_point[DispatchTable::length];

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

// Entry points

/**

 * Returns the return entry table for the given invoke bytecode.

 */

address* TemplateInterpreter::invoke_return_entry_table_for(Bytecodes::Code code) {

  switch (code) {

  case Bytecodes::_invokestatic:

  case Bytecodes::_invokespecial:

  case Bytecodes::_invokevirtual:

  case Bytecodes::_invokehandle:

    return Interpreter::invoke_return_entry_table();

  case Bytecodes::_invokeinterface:

    return Interpreter::invokeinterface_return_entry_table();

  case Bytecodes::_invokedynamic:

    return Interpreter::invokedynamic_return_entry_table();

  default:

    fatal("invalid bytecode: %s", Bytecodes::name(code));

    return NULL;

  }

}

/**

 * Returns the return entry address for the given top-of-stack state and bytecode.

 */

address TemplateInterpreter::return_entry(TosState state, int length, Bytecodes::Code code) {

  guarantee(0 <= length && length < Interpreter::number_of_return_entries, "illegal length");

  const int index = TosState_as_index(state);

  switch (code) {

  case Bytecodes::_invokestatic:

  case Bytecodes::_invokespecial:

  case Bytecodes::_invokevirtual:

  case Bytecodes::_invokehandle:

    return _invoke_return_entry[index];

  case Bytecodes::_invokeinterface:

    return _invokeinterface_return_entry[index];

  case Bytecodes::_invokedynamic:

    return _invokedynamic_return_entry[index];

  default:

    assert(!Bytecodes::is_invoke(code), "invoke instructions should be handled separately: %s", Bytecodes::name(code));

    address entry = _return_entry[length].entry(state);

    vmassert(entry != NULL, "unsupported return entry requested, length=%d state=%d", length, index);

    return entry;

  }

}

address TemplateInterpreter::deopt_entry(TosState state, int length) {

  guarantee(0 <= length && length < Interpreter::number_of_deopt_entries, "illegal length");

  address entry = _deopt_entry[length].entry(state);

  vmassert(entry != NULL, "unsupported deopt entry requested, length=%d state=%d", length, TosState_as_index(state));

  return entry;

}

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

// Suport for invokes

int TemplateInterpreter::TosState_as_index(TosState state) {

  assert( state < number_of_states , "Invalid state in TosState_as_index");

  assert(0 <= (int)state && (int)state < TemplateInterpreter::number_of_return_addrs, "index out of bounds");

  return (int)state;

}

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

// Safepoint support

static inline void copy_table(address* from, address* to, int size) {

  // Copy non-overlapping tables.

  if (SafepointSynchronize::is_at_safepoint()) {

    // Nothing is using the table at a safepoint so skip atomic word copy.

    Copy::disjoint_words((HeapWord*)from, (HeapWord*)to, (size_t)size);

  } else {

    // Use atomic word copy when not at a safepoint for safety.

    Copy::disjoint_words_atomic((HeapWord*)from, (HeapWord*)to, (size_t)size);

  }

}

void TemplateInterpreter::notice_safepoints() {

  if (!_notice_safepoints) {

    log_debug(interpreter, safepoint)("switching active_table to safept_table.");

    // switch to safepoint dispatch table

    _notice_safepoints = true;

    copy_table((address*)&_safept_table, (address*)&_active_table, sizeof(_active_table) / sizeof(address));

  } else {

    log_debug(interpreter, safepoint)("active_table is already safept_table; "

                                      "notice_safepoints() call is no-op.");

  }

}

// switch from the dispatch table which notices safepoints back to the

// normal dispatch table.  So that we can notice single stepping points,

// keep the safepoint dispatch table if we are single stepping in JVMTI.

// Note that the should_post_single_step test is exactly as fast as the

// JvmtiExport::_enabled test and covers both cases.

void TemplateInterpreter::ignore_safepoints() {

  if (_notice_safepoints) {

    if (!JvmtiExport::should_post_single_step()) {

      log_debug(interpreter, safepoint)("switching active_table to normal_table.");

      // switch to normal dispatch table

      _notice_safepoints = false;

      copy_table((address*)&_normal_table, (address*)&_active_table, sizeof(_active_table) / sizeof(address));

    } else {

      log_debug(interpreter, safepoint)("single stepping is still active; "

                                        "ignoring ignore_safepoints() call.");

    }

  } else {

    log_debug(interpreter, safepoint)("active_table is already normal_table; "

                                      "ignore_safepoints() call is no-op.");

  }

}

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

// Deoptimization support

// If deoptimization happens, this function returns the point of next bytecode to continue execution

address TemplateInterpreter::deopt_continue_after_entry(Method* method, address bcp, int callee_parameters, bool is_top_frame) {

  return AbstractInterpreter::deopt_continue_after_entry(method, bcp, callee_parameters, is_top_frame);

}

// If deoptimization happens, this function returns the point where the interpreter reexecutes

// the bytecode.

// Note: Bytecodes::_athrow (C1 only) and Bytecodes::_return are the special cases

//       that do not return "Interpreter::deopt_entry(vtos, 0)"

address TemplateInterpreter::deopt_reexecute_entry(Method* method, address bcp) {

  assert(method->contains(bcp), "just checkin'");

  Bytecodes::Code code   = Bytecodes::code_at(method, bcp);

  if (code == Bytecodes::_return_register_finalizer) {

    // This is used for deopt during registration of finalizers

    // during Object.<init>.  We simply need to resume execution at

    // the standard return vtos bytecode to pop the frame normally.

    // reexecuting the real bytecode would cause double registration

    // of the finalizable object.

    return Interpreter::deopt_reexecute_return_entry();

  } else {

    return AbstractInterpreter::deopt_reexecute_entry(method, bcp);

  }

}

// If deoptimization happens, the interpreter should reexecute this bytecode.

// This function mainly helps the compilers to set up the reexecute bit.

bool TemplateInterpreter::bytecode_should_reexecute(Bytecodes::Code code) {

  if (code == Bytecodes::_return) {

    //Yes, we consider Bytecodes::_return as a special case of reexecution

    return true;

  } else {

    return AbstractInterpreter::bytecode_should_reexecute(code);

  }

}

InterpreterCodelet* TemplateInterpreter::codelet_containing(address pc) {

  return (InterpreterCodelet*)_code->stub_containing(pc);

}

#endif // !CC_INTERP