/*

 * 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.

 *

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_c1_ValueStack.cpp.incl"

// Implementation of ValueStack

ValueStack::ValueStack(IRScope* scope, int locals_size, int max_stack_size)

: _scope(scope)

, _locals(locals_size, NULL)

, _stack(max_stack_size)

, _lock_stack(false)

, _locks(1)

{

  assert(scope != NULL, "scope must exist");

}

ValueStack* ValueStack::copy() {

  ValueStack* s = new ValueStack(scope(), locals_size(), max_stack_size());

  s->_stack.appendAll(&_stack);

  s->_locks.appendAll(&_locks);

  s->replace_locals(this);

  return s;

}

ValueStack* ValueStack::copy_locks() {

  int sz = scope()->lock_stack_size();

  if (stack_size() == 0) {

    sz = 0;

  }

  ValueStack* s = new ValueStack(scope(), locals_size(), sz);

  s->_lock_stack = true;

  s->_locks.appendAll(&_locks);

  s->replace_locals(this);

  if (sz > 0) {

    assert(sz <= stack_size(), "lock stack underflow");

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

      s->_stack.append(_stack[i]);

    }

  }

  return s;

}

bool ValueStack::is_same(ValueStack* s) {

  assert(s != NULL, "state must exist");

  assert(scope      () == s->scope      (), "scopes       must correspond");

  assert(locals_size() == s->locals_size(), "locals sizes must correspond");

  return is_same_across_scopes(s);

}

bool ValueStack::is_same_across_scopes(ValueStack* s) {

  assert(s != NULL, "state must exist");

  assert(stack_size () == s->stack_size (), "stack  sizes must correspond");

  assert(locks_size () == s->locks_size (), "locks  sizes must correspond");

  // compare each stack element with the corresponding stack element of s

  int index;

  Value value;

  for_each_stack_value(this, index, value) {

    if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;

  }

  for_each_lock_value(this, index, value) {

    if (value != s->lock_at(index)) return false;

  }

  return true;

}

ValueStack* ValueStack::caller_state() const {

  return scope()->caller_state();

}

void ValueStack::clear_locals() {

  for (int i = _locals.length() - 1; i >= 0; i--) {

    _locals.at_put(i, NULL);

  }

}

void ValueStack::replace_locals(ValueStack* with) {

  assert(locals_size() == with->locals_size(), "number of locals must match");

  for (int i = locals_size() - 1; i >= 0; i--) {

    _locals.at_put(i, with->_locals.at(i));

  }

}

void ValueStack::pin_stack_for_linear_scan() {

  for_each_state_value(this, v,

    if (v->as_Constant() == NULL && v->as_Local() == NULL) {

      v->pin(Instruction::PinStackForStateSplit);

    }

  );

}

// apply function to all values of a list; factored out from values_do(f)

void ValueStack::apply(Values list, void f(Value*)) {

  for (int i = 0; i < list.length(); i++) {

    Value* va = list.adr_at(i);

    Value v0 = *va;

    if (v0 != NULL) {

      if (!v0->type()->is_illegal()) {

        assert(v0->as_HiWord() == NULL, "should never see HiWord during traversal");

        f(va);

#ifdef ASSERT

        Value v1 = *va;

        if (v0 != v1) {

          assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");

          if (v0->type()->is_double_word()) {

            list.at_put(i + 1, v0->hi_word());

          }

        }

#endif

        if (v0->type()->is_double_word()) i++;

      }

    }

  }

}

void ValueStack::values_do(void f(Value*)) {

  apply(_stack, f);

  apply(_locks, f);

  ValueStack* state = this;

  for_each_state(state) {

    apply(state->_locals, f);

  }

}

Values* ValueStack::pop_arguments(int argument_size) {

  assert(stack_size() >= argument_size, "stack too small or too many arguments");

  int base = stack_size() - argument_size;

  Values* args = new Values(argument_size);

  for (int i = base; i < stack_size();) args->push(stack_at_inc(i));

  truncate_stack(base);

  return args;

}

int ValueStack::lock(IRScope* scope, Value obj) {

  _locks.push(obj);

  scope->set_min_number_of_locks(locks_size());

  return locks_size() - 1;

}

int ValueStack::unlock() {

  _locks.pop();

  return locks_size();

}

ValueStack* ValueStack::push_scope(IRScope* scope) {

  assert(scope->caller() == _scope, "scopes must have caller/callee relationship");

  ValueStack* res = new ValueStack(scope,

                                   scope->method()->max_locals(),

                                   max_stack_size() + scope->method()->max_stack());

  // Preserves stack and monitors.

  res->_stack.appendAll(&_stack);

  res->_locks.appendAll(&_locks);

  assert(res->_stack.size() <= res->max_stack_size(), "stack overflow");

  return res;

}

ValueStack* ValueStack::pop_scope() {

  assert(_scope->caller() != NULL, "scope must have caller");

  IRScope* scope = _scope->caller();

  int max_stack = max_stack_size() - _scope->method()->max_stack();

  assert(max_stack >= 0, "stack underflow");

  ValueStack* res = new ValueStack(scope,

                                   scope->method()->max_locals(),

                                   max_stack);

  // Preserves stack and monitors. Restores local and store state from caller scope.

  res->_stack.appendAll(&_stack);

  res->_locks.appendAll(&_locks);

  ValueStack* caller = caller_state();

  if (caller != NULL) {

    for (int i = 0; i < caller->_locals.length(); i++) {

      res->_locals.at_put(i, caller->_locals.at(i));

    }

    assert(res->_locals.length() == res->scope()->method()->max_locals(), "just checking");

  }

  assert(res->_stack.size() <= res->max_stack_size(), "stack overflow");

  return res;

}

void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {

  assert(stack_at(index)->as_Phi() == NULL || stack_at(index)->as_Phi()->block() != b, "phi function already created");

  ValueType* t = stack_at(index)->type();

  Value phi = new Phi(t, b, -index - 1);

  _stack[index] = phi;

#ifdef ASSERT

  if (t->is_double_word()) {

    _stack[index + 1] = phi->hi_word();

  }

#endif

}

void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {

  assert(local_at(index)->as_Phi() == NULL || local_at(index)->as_Phi()->block() != b, "phi function already created");

  ValueType* t = local_at(index)->type();

  Value phi = new Phi(t, b, index);

  store_local(index, phi);

}

#ifndef PRODUCT

void ValueStack::print() {

  if (stack_is_empty()) {

    tty->print_cr("empty stack");

  } else {

    InstructionPrinter ip;

    for (int i = 0; i < stack_size();) {

      Value t = stack_at_inc(i);

      tty->print("%2d  ", i);

      ip.print_instr(t);

      tty->cr();

    }

  }

  if (!no_active_locks()) {

    InstructionPrinter ip;

    for (int i = 0; i < locks_size(); i--) {

      Value t = lock_at(i);

      tty->print("lock %2d  ", i);

      if (t == NULL) {

        tty->print("this");

      } else {

        ip.print_instr(t);

      }

      tty->cr();

    }

  }

  if (locals_size() > 0) {

    InstructionPrinter ip;

    for (int i = 0; i < locals_size();) {

      Value l = _locals[i];

      tty->print("local %d ", i);

      if (l == NULL) {

        tty->print("null");

        i ++;

      } else {

        ip.print_instr(l);

        if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;

      }

      tty->cr();

    }

  }

}

void ValueStack::verify() {

  Unimplemented();

}

#endif // PRODUCT