/*
	dags.h

	DAG representation of basic blocks

	Copyright (C) 2012 Bill Currie <bill@taniwha.org>

	Author: Bill Currie <bill@taniwha.org>
	Date: 2012/05/08

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program 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 for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifndef dags_h
#define dags_h

/** \defgroup qfcc_dags DAG building
	\ingroup qfcc
*/
//@{

typedef struct daglabel_s {
	/// \name attached identifer linked list
	//@{
	struct daglabel_s *next;
	struct daglabel_s **prev;
	//@}
	struct daglabel_s *daglabel_chain;	///< all labels created for a dag
	const char *opcode;			///< not if op
	struct operand_s *op;		///< not if opcode;
	struct dagnode_s *dagnode;	///< node with which this label is associated
} daglabel_t;

typedef struct dagnode_s {
	struct dagnode_s *next;
	int         print_count;	///< used to avoid double printing nodes
	int         is_child;		///< true if a child node
	daglabel_t *label;			///< ident/const if leaf node, or operator
	/// \name child nodes
	/// All three child nodes will be null if this node is a leaf
	/// If \a a is null, both \a b and \a c must also be null. If \a is not
	/// null, either \a b or \a c or even both may be non-null. Both \a b and
	/// \a c being non-null is reserved for the few opcodes that take three
	/// inputs (rcall2+, 3 op state, indirect move, indexed pointer assignment)
	/// \a b and \a c are used to help keep track of the original statement
	/// operands
	//@{
	struct dagnode_s *a;
	struct dagnode_s *b;
	struct dagnode_s *c;
	//@}
	daglabel_t *identifiers;	///< list of identifiers with value of this node
} dagnode_t;

const char *daglabel_string (daglabel_t *label);
struct dstring_s;
void print_dag (struct dstring_s *dstr, dagnode_t *node);
struct sblock_s;

daglabel_t *operand_label (struct operand_s *op);

/** Make a dag for a single basic block.

	\param block	The basic block for which the dag will be created.
	\return			The dag representing the basic block.
*/
dagnode_t *make_dag (const struct sblock_s *block);

//@}

#endif//dags_h