/*
 * Copyright 1999-2007 Sun Microsystems, Inc.  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 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.
 *
 */

class SharkState;

class SharkBlock : public ResourceObj {
 public:
  SharkBlock(SharkBuilder*     builder,
             ciMethod*         target,
             ciBytecodeStream* iter,
             llvm::Value*      thread)
    : _builder(builder),
      _target(target),
      _iter(iter),
      _current_state(NULL),
      _thread(thread) {}

 private:
  SharkBuilder*     _builder;
  ciMethod*         _target;
  ciBytecodeStream* _iter;
  SharkState*       _current_state;
  llvm::Value*      _thread;

 public:
  SharkBuilder* builder() const
  {
    return _builder;
  }
  ciMethod* target() const
  {
    return _target;
  }
  ciBytecodeStream* iter() const
  {
    return _iter;
  }
  llvm::Value* thread() const
  {
    return _thread;
  }

  // Target properties
 public:
  int max_locals() const
  {
    return target()->max_locals();
  }
  int max_stack() const
  {
    return target()->max_stack();
  }  
  
  // Bytecode stream
 public:
  Bytecodes::Code bc() const
  {
    return iter()->cur_bc();
  }
  int bci() const
  {
    return iter()->cur_bci();
  }

  // Entry state
 protected:
  virtual SharkState* entry_state();
  
  // Current state
 private:
  SharkState* initial_current_state();
  
 public:
  SharkState* current_state()
  {
    if (_current_state == NULL)
      set_current_state(initial_current_state());
    return _current_state;
  }

 protected:
  void set_current_state(SharkState* current_state)
  {
    _current_state = current_state;
  }

  // Local variables  
 protected:
  SharkValue* local(int index)
  {
    SharkValue *value = current_state()->local(index);
    assert(value != NULL, "shouldn't be");
    assert(value->is_one_word() ||
           (index + 1 < max_locals() &&
            current_state()->local(index + 1) == NULL), "should be");
    return value;
  }
  void set_local(int index, SharkValue* value)
  {
    assert(value != NULL, "shouldn't be");
    current_state()->set_local(index, value);
    if (value->is_two_word())
      current_state()->set_local(index + 1, NULL);
  }

  // Expression stack (raw)
 protected:
  void xpush(SharkValue* value)
  {
    current_state()->push(value);
  }
  SharkValue* xpop()
  {
    return current_state()->pop();
  }
  SharkValue* xstack(int slot)
  {
    SharkValue *value = current_state()->stack(slot);
    assert(value != NULL, "shouldn't be");
    assert(value->is_one_word() ||
           (slot > 0 &&
            current_state()->stack(slot - 1) == NULL), "should be");
    return value;
  }
  int xstack_depth()
  {
    return current_state()->stack_depth();
  }

  // Expression stack (cooked)
 protected:
  void push(SharkValue* value)
  {
    assert(value != NULL, "shouldn't be");
    xpush(value);
    if (value->is_two_word())
      xpush(NULL);
  }
  SharkValue* pop()
  {
    int size = current_state()->stack(0) == NULL ? 2 : 1;
    if (size == 2)
      xpop();
    SharkValue *value = xpop();
    assert(value && value->size() == size, "should be");
    return value;
  }
  SharkValue* pop_result(BasicType type)
  {
    SharkValue *result = pop();

#ifdef ASSERT
    switch (result->basic_type()) {
    case T_BOOLEAN:
    case T_BYTE:
    case T_CHAR:
    case T_SHORT:
      assert(type == T_INT, "type mismatch");
      break;

    case T_ARRAY:
      assert(type == T_OBJECT, "type mismatch");
      break;

    default:
      assert(result->basic_type() == type, "type mismatch");
    }
#endif // ASSERT

    return result;
  }

  // Code generation
 public:
  virtual void emit_IR();

 protected:
  void parse_bytecode(int start, int limit);

  // Helpers
 protected:
  virtual void do_zero_check(SharkValue* value);
  virtual llvm::Value* lookup_for_ldc();
  virtual llvm::Value* lookup_for_field_access();

  // Leaf calls
 protected:
  llvm::CallInst* call_vm_leaf(llvm::Constant* callee, llvm::Value* arg1)
  {
    return builder()->CreateCall(callee, arg1);
  }

  // Zero checking
 protected:
  void check_null(SharkValue* object)
  {
    zero_check(object);
  }
  void check_divide_by_zero(SharkValue* value)
  {
    zero_check(value);
  }
 private:
  void zero_check(SharkValue* value)
  {
    if (!value->zero_checked())
      do_zero_check(value);
  }

  // Safepoints
 protected:
  virtual void add_safepoint();

  // ldc*
 private:
  void do_ldc()
  {
    SharkValue *value = SharkValue::from_ciConstant(iter()->get_constant());
    if (value == NULL)
      value = SharkValue::create_jobject(lookup_for_ldc());
    push(value);
  }

  // arraylength
 protected:
  virtual void do_arraylength();

  // *aload and *astore
 protected:
  virtual void do_aload(BasicType basic_type);
  virtual void do_astore(BasicType basic_type);

  // *div and *rem
 private:
  void do_idiv()
  {
    do_div_or_rem(false, false);
  }
  void do_irem()
  {
    do_div_or_rem(false, true);
  }
  void do_ldiv()
  {
    do_div_or_rem(true, false);
  }
  void do_lrem()
  {
    do_div_or_rem(true, true);
  }
  void do_div_or_rem(bool is_long, bool is_rem);  

  // get* and put*
 private:
  void do_getstatic()
  {
    do_field_access(true, false);
  }
  void do_getfield()
  {
    do_field_access(true, true);
  }
  void do_putstatic()
  {
    do_field_access(false, false);
  }
  void do_putfield()
  {
    do_field_access(false, true);
  }
  void do_field_access(bool is_get, bool is_field);

  // lcmp and [fd]cmp[lg]
 private:
  void do_lcmp();
  void do_fcmp(bool is_double, bool unordered_is_greater);

  // *return and athrow
 protected:
  virtual void do_return(BasicType type);
  virtual void do_athrow();

  // goto*
 protected:
  virtual void do_goto();

  // jsr* and ret
 protected:
  virtual void do_jsr();
  virtual void do_ret();

  // if*
 protected:
  virtual void do_if(llvm::ICmpInst::Predicate p, SharkValue* b, SharkValue* a);

  // *switch
 protected:
  int switch_default_dest();
  int switch_table_length();
  int switch_key(int i);
  int switch_dest(int i);

  virtual void do_switch();
  
  // invoke*
 protected:
  virtual void do_call();

  // checkcast and instanceof
 protected:
  virtual void do_instance_check();

  // new and *newarray
 protected:
  virtual void do_new();
  virtual void do_newarray();
  virtual void do_anewarray();
  virtual void do_multianewarray();

  // monitorenter and monitorexit
 protected:
  virtual void do_monitorenter();
  virtual void do_monitorexit();
};