/*

 * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2008, 2009 Red Hat, Inc.

 * 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 "ci/ciType.hpp"

#include "ci/ciTypeFlow.hpp"

#include "memory/allocation.hpp"

#include "shark/sharkBuilder.hpp"

#include "shark/sharkCacheDecache.hpp"

#include "shark/sharkState.hpp"

#include "shark/sharkTopLevelBlock.hpp"

#include "shark/sharkType.hpp"

#include "shark/sharkValue.hpp"

using namespace llvm;

void SharkState::initialize(const SharkState *state) {

  _locals = NEW_RESOURCE_ARRAY(SharkValue*, max_locals());

  _stack  = NEW_RESOURCE_ARRAY(SharkValue*, max_stack());

  NOT_PRODUCT(memset(_locals, 23, max_locals() * sizeof(SharkValue *)));

  NOT_PRODUCT(memset(_stack,  23, max_stack()  * sizeof(SharkValue *)));

  _sp = _stack;

  if (state) {

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

      SharkValue *value = state->local(i);

      if (value)

        value = value->clone();

      set_local(i, value);

    }

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

      SharkValue *value = state->stack(i);

      if (value)

        value = value->clone();

      push(value);

    }

  }

  set_num_monitors(state ? state->num_monitors() : 0);

}

bool SharkState::equal_to(SharkState *other) {

  if (target() != other->target())

    return false;

  if (method() != other->method())

    return false;

  if (oop_tmp() != other->oop_tmp())

    return false;

  if (max_locals() != other->max_locals())

    return false;

  if (stack_depth() != other->stack_depth())

    return false;

  if (num_monitors() != other->num_monitors())

    return false;

  if (has_safepointed() != other->has_safepointed())

    return false;

  // Local variables

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

    SharkValue *value = local(i);

    SharkValue *other_value = other->local(i);

    if (value == NULL) {

      if (other_value != NULL)

        return false;

    }

    else {

      if (other_value == NULL)

        return false;

      if (!value->equal_to(other_value))

        return false;

    }

  }

  // Expression stack

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

    SharkValue *value = stack(i);

    SharkValue *other_value = other->stack(i);

    if (value == NULL) {

      if (other_value != NULL)

        return false;

    }

    else {

      if (other_value == NULL)

        return false;

      if (!value->equal_to(other_value))

        return false;

    }

  }

  return true;

}

void SharkState::merge(SharkState* other,

                       BasicBlock* other_block,

                       BasicBlock* this_block) {

  // Method

  Value *this_method = this->method();

  Value *other_method = other->method();

  if (this_method != other_method) {

    PHINode *phi = builder()->CreatePHI(SharkType::Method_type(), 0, "method");

    phi->addIncoming(this_method, this_block);

    phi->addIncoming(other_method, other_block);

    set_method(phi);

  }

  // Temporary oop slot

  Value *this_oop_tmp = this->oop_tmp();

  Value *other_oop_tmp = other->oop_tmp();

  if (this_oop_tmp != other_oop_tmp) {

    assert(this_oop_tmp && other_oop_tmp, "can't merge NULL with non-NULL");

    PHINode *phi = builder()->CreatePHI(SharkType::oop_type(), 0, "oop_tmp");

    phi->addIncoming(this_oop_tmp, this_block);

    phi->addIncoming(other_oop_tmp, other_block);

    set_oop_tmp(phi);

  }

  // Monitors

  assert(this->num_monitors() == other->num_monitors(), "should be");

  // Local variables

  assert(this->max_locals() == other->max_locals(), "should be");

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

    SharkValue *this_value = this->local(i);

    SharkValue *other_value = other->local(i);

    assert((this_value == NULL) == (other_value == NULL), "should be");

    if (this_value != NULL) {

      char name[18];

      snprintf(name, sizeof(name), "local_%d_", i);

      set_local(i, this_value->merge(

        builder(), other_value, other_block, this_block, name));

    }

  }

  // Expression stack

  assert(this->stack_depth() == other->stack_depth(), "should be");

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

    SharkValue *this_value = this->stack(i);

    SharkValue *other_value = other->stack(i);

    assert((this_value == NULL) == (other_value == NULL), "should be");

    if (this_value != NULL) {

      char name[18];

      snprintf(name, sizeof(name), "stack_%d_", i);

      set_stack(i, this_value->merge(

        builder(), other_value, other_block, this_block, name));

    }

  }

  // Safepointed status

  set_has_safepointed(this->has_safepointed() && other->has_safepointed());

}

void SharkState::replace_all(SharkValue* old_value, SharkValue* new_value) {

  // Local variables

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

    if (local(i) == old_value)

      set_local(i, new_value);

  }

  // Expression stack

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

    if (stack(i) == old_value)

      set_stack(i, new_value);

  }

}

SharkNormalEntryState::SharkNormalEntryState(SharkTopLevelBlock* block,

                                             Value*              method)

  : SharkState(block) {

  assert(!block->stack_depth_at_entry(), "entry block shouldn't have stack");

  // Local variables

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

    ciType *type = block->local_type_at_entry(i);

    SharkValue *value = NULL;

    switch (type->basic_type()) {

    case T_INT:

    case T_LONG:

    case T_FLOAT:

    case T_DOUBLE:

    case T_OBJECT:

    case T_ARRAY:

      if (i >= arg_size()) {

        ShouldNotReachHere();

      }

      value = SharkValue::create_generic(type, NULL, i == 0 && !is_static());

      break;

    case ciTypeFlow::StateVector::T_NULL:

      value = SharkValue::null();

      break;

    case ciTypeFlow::StateVector::T_BOTTOM:

      break;

    case ciTypeFlow::StateVector::T_LONG2:

    case ciTypeFlow::StateVector::T_DOUBLE2:

      break;

    default:

      ShouldNotReachHere();

    }

    set_local(i, value);

  }

  SharkNormalEntryCacher(block->function(), method).scan(this);

}

SharkOSREntryState::SharkOSREntryState(SharkTopLevelBlock* block,

                                       Value*              method,

                                       Value*              osr_buf)

  : SharkState(block) {

  assert(block->stack_depth_at_entry() == 0, "entry block shouldn't have stack");

  set_num_monitors(block->ciblock()->monitor_count());

  // Local variables

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

    ciType *type = block->local_type_at_entry(i);

    SharkValue *value = NULL;

    switch (type->basic_type()) {

    case T_INT:

    case T_LONG:

    case T_FLOAT:

    case T_DOUBLE:

    case T_OBJECT:

    case T_ARRAY:

      value = SharkValue::create_generic(type, NULL, false);

      break;

    case ciTypeFlow::StateVector::T_NULL:

      value = SharkValue::null();

      break;

    case ciTypeFlow::StateVector::T_BOTTOM:

      break;

    case ciTypeFlow::StateVector::T_LONG2:

    case ciTypeFlow::StateVector::T_DOUBLE2:

      break;

    default:

      ShouldNotReachHere();

    }

    set_local(i, value);

  }

  SharkOSREntryCacher(block->function(), method, osr_buf).scan(this);

}

SharkPHIState::SharkPHIState(SharkTopLevelBlock* block)

  : SharkState(block), _block(block) {

  BasicBlock *saved_insert_point = builder()->GetInsertBlock();

  builder()->SetInsertPoint(block->entry_block());

  char name[18];

  // Method

  set_method(builder()->CreatePHI(SharkType::Method_type(), 0, "method"));

  // Local variables

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

    ciType *type = block->local_type_at_entry(i);

    if (type->basic_type() == (BasicType) ciTypeFlow::StateVector::T_NULL) {

      // XXX we could do all kinds of clever stuff here

      type = ciType::make(T_OBJECT); // XXX what about T_ARRAY?

    }

    SharkValue *value = NULL;

    switch (type->basic_type()) {

    case T_INT:

    case T_LONG:

    case T_FLOAT:

    case T_DOUBLE:

    case T_OBJECT:

    case T_ARRAY:

      snprintf(name, sizeof(name), "local_%d_", i);

      value = SharkValue::create_phi(

        type, builder()->CreatePHI(SharkType::to_stackType(type), 0, name));

      break;

    case T_ADDRESS:

      value = SharkValue::address_constant(type->as_return_address()->bci());

      break;

    case ciTypeFlow::StateVector::T_BOTTOM:

      break;

    case ciTypeFlow::StateVector::T_LONG2:

    case ciTypeFlow::StateVector::T_DOUBLE2:

      break;

    default:

      ShouldNotReachHere();

    }

    set_local(i, value);

  }

  // Expression stack

  for (int i = 0; i < block->stack_depth_at_entry(); i++) {

    ciType *type = block->stack_type_at_entry(i);

    if (type->basic_type() == (BasicType) ciTypeFlow::StateVector::T_NULL) {

      // XXX we could do all kinds of clever stuff here

      type = ciType::make(T_OBJECT); // XXX what about T_ARRAY?

    }

    SharkValue *value = NULL;

    switch (type->basic_type()) {

    case T_INT:

    case T_LONG:

    case T_FLOAT:

    case T_DOUBLE:

    case T_OBJECT:

    case T_ARRAY:

      snprintf(name, sizeof(name), "stack_%d_", i);

      value = SharkValue::create_phi(

        type, builder()->CreatePHI(SharkType::to_stackType(type), 0, name));

      break;

    case T_ADDRESS:

      value = SharkValue::address_constant(type->as_return_address()->bci());

      break;

    case ciTypeFlow::StateVector::T_LONG2:

    case ciTypeFlow::StateVector::T_DOUBLE2:

      break;

    default:

      ShouldNotReachHere();

    }

    push(value);

  }

  // Monitors

  set_num_monitors(block->ciblock()->monitor_count());

  builder()->SetInsertPoint(saved_insert_point);

}

void SharkPHIState::add_incoming(SharkState* incoming_state) {

  BasicBlock *predecessor = builder()->GetInsertBlock();

  // Method

  ((PHINode *) method())->addIncoming(incoming_state->method(), predecessor);

  // Local variables

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

    if (local(i) != NULL)

      local(i)->addIncoming(incoming_state->local(i), predecessor);

  }

  // Expression stack

  int stack_depth = block()->stack_depth_at_entry();

  assert(stack_depth == incoming_state->stack_depth(), "should be");

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

    assert((stack(i) == NULL) == (incoming_state->stack(i) == NULL), "oops");

    if (stack(i))

      stack(i)->addIncoming(incoming_state->stack(i), predecessor);

  }

  // Monitors

  assert(num_monitors() == incoming_state->num_monitors(), "should be");

  // Temporary oop slot

  assert(oop_tmp() == incoming_state->oop_tmp(), "should be");

}