Don't check nunber of Proj's for dead blocks

[libfirm] / ir / ir / irgraph.h

/*
 * Project:     libFIRM
 * File name:   ir/ir/irgraph.c
 * Purpose:     Entry point to the representation of procedure code.
 * Author:      Martin Trapp, Christian Schaefer
 * Modified by: Goetz Lindenmaier
 * Created:
 * CVS-ID:      $Id$
 * Copyright:   (c) 1998-2003 Universität Karlsruhe
 * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
 */

/**
 * @file irgraph.h
 *
 * ir graph construction.
 *
 * @author Martin Trapp, Christian Schaefer
 */

#include <stddef.h>

#include "irop.h"
#include "irextbb.h"

# ifndef _IRGRAPH_H_
# define _IRGRAPH_H_
# include "entity.h"

/* to resolve recursion between irnode.h and irgraph.h */
#ifndef _IR_NODE_TYPEDEF_
#define _IR_NODE_TYPEDEF_
typedef struct ir_node ir_node;
#endif

/* to resolve recursion between entity.h and irgraph.h */
#ifndef _IR_GRAPH_TYPEDEF_
#define _IR_GRAPH_TYPEDEF_
typedef struct ir_graph ir_graph;
#endif

/**
 * @page ir_graph   The struct ir_graph
 *
 *      This struct contains all information about a procedure.
 *      It's allocated directly to memory.
 *
 *      The fields of ir_graph:
 *
 *      *ent             The entity describing this procedure.
 *
 *      The beginning and end of a graph:
 *
 *      *start_block     This ir_node is the block that contains the unique
 *                       start node of the procedure.  With it it contains
 *                       the Proj's on starts results.
 *                       Further all Const nodes are placed in the start block.
 *      *start           This ir_node is the unique start node of the procedure.
 *
 *      *end_block       This ir_node is the block that contains the unique
 *                       end node of the procedure.  This block contains no
 *                       further nodes.
 *      *end             This ir_node is the unique end node of the procedure.
 *
 *      The following nodes are Projs from the start node, held in ir_graph for
 *      simple access:
 *
 *      *frame           The ir_node producing the pointer to the stack frame of
 *                       the procedure as output.  This is the Proj node on the
 *                       third output of the start node.  This output of the start
 *                      node is tagged as pns_frame_base.  In FIRM most local
 *                       variables are modeled as data flow edges.  Static
 *                       allocated arrays can not be represented as data flow
 *                       edges. Therefore FIRM has to represent them in the stack
 *                       frame.
 *
 *      *globals         This models a pointer to a space in the memory where
 *               _all_ global things are held.  Select from this pointer
 *               with a Sel node the pointer to a global variable /
 *               procedure / compiler known function... .
 *
 *      *args        The ir_node that produces the arguments of the method as
 *               it's result.  This is a Proj node on the fourth output of
 *               the start node.  This output is tagged as pn_Start_T_args.
 *
 *      *proj_args        The proj nodes of the args node.
 *
 *      *bad             The Bad node is an auxiliary node. It is needed only once,
 *                       so there is this globally reachable node.
 *
 *      *no_mem          The NoMem node is an auxiliary node. It is needed only once,
 *                       so there is this globally reachable node.
 *
 *      Data structures that are private to a graph:
 *
 *      *obst            An obstack that contains all nodes.
 *
 *      *current_block   A pointer to the current block.  Any node created with
 *                       one of the node constructors (new_<opcode>) are assigned
 *                       to this block.  It can be set with set_cur_block(block).
 *                       Only needed for ir construction.
 *
 *      params/n_loc     An int giving the number of local variables in this
 *               procedure.  This is needed for ir construction. Name will
 *               be changed.
 *
 *      *value_table     This hash table (pset) is used for global value numbering
 *               for optimizing use in iropt.c.
 *
 *      *Phi_in_stack;   a stack needed for automatic Phi construction, needed only
 *               during ir construction.
 *
 *      visited          A int used as flag to traverse the ir_graph.
 *
 *      block_visited    A int used as a flag to traverse block nodes in the graph.
 */

/** Global variable holding the current ir graph.
 *
 *  This global variable is used by the ir construction
 *  interface in ircons and by the optimizations.
 *  Further it is set by all walker functions.
 */
extern ir_graph *current_ir_graph;

ir_graph *get_current_ir_graph(void);
void      set_current_ir_graph(ir_graph *graph);

/** This flag indicate the current view. The behavior of some methods
 * (get_irn_*, set_irn_*) is influenced by this flag. */
int get_interprocedural_view(void);
void set_interprocedural_view(int state);

/**
 * Create a new ir graph to build ir for a procedure.
 *
 * @param ent    A pointer to an entity representing the procedure,
 *               i.e., the type of the entity must be of a method type.
 *
 * @param n_loc  The number of local variables in this procedure including
 *               the procedure parameters.
 *
 * This constructor generates the basic infrastructure needed to
 * represent a procedure in FIRM.
 *
 * It allocates an ir_graph and sets the field irg of the entity ent
 * as well as current_ir_graph to point to this graph.
 * Further it allocates the following nodes needed for every
 * procedure:
 *
 * - The start block containing a start node and Proj nodes for it's
 *   five results (X, M, P, P, T).
 * - The end block containing an end node. This block is not matured
 *   after executing new_ir_graph() as predecessors need to be added to it.
 *   (Maturing a block means fixing it's number of predecessors.)
 * - The current block, which is empty and also not matured.
 *
 * Further it enters the global store into the data structure of the start
 * block that contains all valid values in this block (set_store()).  This
 * data structure is used to build the Phi nodes and removed after
 * completion of the graph.  There is no path from end to start in the
 * graph after calling ir_graph.
 *
 * The op_pin_state of the graph is set to "op_pin_state_pinned"
 * if no global cse was performed on the graph.
 * It is set to "op_pin_state_floats" if global cse was performed
 * (and during construction: did actually change something).
 * Code placement is necessary.
 *
 * @see new_pseudo_ir_graph()
 */
ir_graph *new_ir_graph (entity *ent, int n_loc);

/** Frees the passed irgraph.
 * Deallocates all nodes in this graph and the ir_graph structure.
 * Sets the field irgraph in the corresponding entity to NULL.
 * Does not remove the irgraph from the list in irprog (requires
 * inefficient search, call remove_irp_irg by hand).
 * Does not free types, entities or modes that are used only by this
 * graph, nor the entity standing for this graph.
 */
void free_ir_graph (ir_graph *irg);

/* --- access routines for all ir_graph attributes --- */

/**
 *   Checks whether a pointer points to a ir graph.
 *
 *   @param thing     an arbitrary pointer
 *
 *   @return
 *       true if the thing is a ir graph, else false
 */
int      is_ir_graph(const void *thing);

/* #define get_irg_entity get_irg_ent */
/* #define set_irg_entity set_irg_ent */
entity  *get_irg_entity (const ir_graph *irg);
void     set_irg_entity (ir_graph *irg, entity *ent);

type    *get_irg_frame_type (ir_graph *irg);
void     set_irg_frame_type (ir_graph *irg, type *ftp);

ir_node *get_irg_start_block (const ir_graph *irg);
void     set_irg_start_block (ir_graph *irg, ir_node *node);

ir_node *get_irg_start (const ir_graph *irg);
void     set_irg_start (ir_graph *irg, ir_node *node);

ir_node *get_irg_end_block (const ir_graph *irg);
void     set_irg_end_block (ir_graph *irg, ir_node *node);

ir_node *get_irg_end (const ir_graph *irg);
void     set_irg_end (ir_graph *irg, ir_node *node);

/* The fields end_reg and end_except contain the end nodes of the
   interprocedural view.  If the view is not constructed they contain
   the normal end node. */
ir_node *get_irg_end_reg (const ir_graph *irg);
void     set_irg_end_reg (ir_graph *irg, ir_node *node);

ir_node *get_irg_end_except (const ir_graph *irg);
void     set_irg_end_except (ir_graph *irg, ir_node *node);


/* @@@ oblivious, no more supported. */
ir_node *get_irg_cstore (const ir_graph *irg);
void     set_irg_cstore (ir_graph *irg, ir_node *node);
/* end oblivious */

/** Returns the node that represents the frame pointer. */
ir_node *get_irg_frame (const ir_graph *irg);
/** Sets the node that represents the frame pointer. */
void     set_irg_frame (ir_graph *irg, ir_node *node);

/** Returns the node that represents the global pointer. */
ir_node *get_irg_globals (const ir_graph *irg);
/** Sets the node that represents the global pointer. */
void     set_irg_globals (ir_graph *irg, ir_node *node);

/** Returns the node that represents the initial memory. */
ir_node *get_irg_initial_mem (const ir_graph *irg);
/** Sets the node that represents the initial memory. */
void     set_irg_initial_mem (ir_graph *irg, ir_node *node);

/** Returns the node that represents the argument pointer. */
ir_node *get_irg_args (const ir_graph *irg);
/** Sets the node that represents the argument pointer. */
void     set_irg_args (ir_graph *irg, ir_node *node);

/** Returns an array of the nodes of the argument pointer. */
ir_node **get_irg_proj_args (const ir_graph *irg);
/** Sets the array of the nodes of the argument pointer. */
void     set_irg_proj_args (ir_graph *irg, ir_node **nodes);

/** Returns the current block of a graph. */
ir_node *get_irg_current_block (const ir_graph *irg);
/** Sets the current block of a graph. */
void     set_irg_current_block (ir_graph *irg, ir_node *node);

/** Returns the Bad node.  Use new_Bad() instead!! */
ir_node *get_irg_bad (const ir_graph *irg);
void     set_irg_bad (ir_graph *irg, ir_node *node);

/** Returns the NoMem node.  Use new_NoMem() instead!! */
ir_node *get_irg_no_mem (const ir_graph *irg);
void     set_irg_no_mem (ir_graph *irg, ir_node *node);

/** Returns the number of value numbers of a graph. */
int      get_irg_n_locs (ir_graph *irg);

/** Returns the graph number. */
long     get_irg_graph_nr(ir_graph *irg);

/********************************************************************************/
/* States of an ir_graph.                                                       */
/********************************************************************************/

/*
   information associated with the graph.  Optimizations invalidate these
   states.  */

/** The states of an ir graph.
 *
 * state phase values: phase_building, phase_high, phase_low.
 *
 * The graph is in phase_building during construction of the irgraph.
 * The construction is finished by a call to finalize_cons().
 *
 * Finalize_cons() sets the state to phase_high.  All Firm nodes are
 * allowed.
 *
 * To get the irgraph into phase_low all Sel nodes must be removed and
 * replaced by explicit address computations.  SymConst size and
 * type tag nodes must be removed (@@@ really?).  Initialization of
 * memory allocated by Alloc must be explicit.  @@@ More conditions?
 *
 */
typedef enum {
  phase_building,
  phase_high,
  phase_low
} irg_phase_state;

/** returns the phase_state of an IR graph. */
irg_phase_state get_irg_phase_state (const ir_graph *irg);

/** sets the phase state of an IR graph. */
void set_irg_phase_low(ir_graph *irg);

/** state: op_pin_state_pinned
   The graph is "op_pin_state_pinned" if all nodes are associated with a basic block.
   It is in state "op_pin_state_floats" if nodes are in arbitrary blocks.  In state
   "op_pin_state_floats" the block predecessor is set in all nodes, but this can be an
   invalid block, i.e., the block is not a dominator of all the uses of
   the node.
   The enum op_pin_state is defined in irop.h. */
op_pin_state get_irg_pinned (const ir_graph *irg);

/** state: outs_state
 *  Outs are the back edges or def-use edges of ir nodes.
 *  Values:  outs_none, outs_consistent, outs_inconsistent */
typedef enum {
  outs_none,         /**< Outs are not computed, no memory is allocated. */
  outs_consistent,   /**< Outs are computed and correct. */
  outs_inconsistent  /**< Outs have been computed, memory is still allocated,
                        but the graph has been changed since. */
} irg_outs_state;
irg_outs_state get_irg_outs_state(const ir_graph *irg);
void           set_irg_outs_inconsistent(ir_graph *irg);

/** state: dom_state
 * Signals the state of the dominator information.
 */
typedef enum {
  dom_none,             /**< dominator are not computed, no memory is allocated */
  dom_consistent,       /**< dominator information is computed and correct */
  dom_inconsistent      /**< dominator information is computed but the graph has been changed since */
} irg_dom_state;

/** returns the dom_state of an IR graph. */
irg_dom_state get_irg_dom_state(const ir_graph *irg);

/** sets the dom_state of an IR graph. */
void set_irg_dom_inconsistent(ir_graph *irg);

/** state: loopinfo_state
 *  Loop information describes the loops within the control and
 *  data flow of the procedure.
 */
typedef enum {
  loopinfo_none             = 0,       /**< No loop information is constructed. Default. */
  loopinfo_constructed      = 1,       /**< Some kind of loop information is constructed. */
  loopinfo_valid            = 2,       /**< Loop information is valid. */
  loopinfo_cf               = 4,       /**< Loop information constructed for control flow only. */
  loopinfo_inter            = 8,       /**< Loop information for interprocedural view. */

  loopinfo_for_firmjni      = 16,      /**< A hack for firmjni:  all enums must differ as they
                                          are used in a switch. */

  /** IntRAprocedural loop information constructed and valid. */
  loopinfo_consistent         = loopinfo_constructed | loopinfo_for_firmjni | loopinfo_valid,
  /** IntRAprocedural loop information constructed and invalid. */
  loopinfo_inconsistent       = loopinfo_constructed | loopinfo_for_firmjni,

  /** IntERprocedural loop information constructed and valid. */
  loopinfo_ip_consistent      = loopinfo_constructed | loopinfo_inter | loopinfo_valid,
  /** IntERprocedural loop information constructed and invalid. */
  loopinfo_ip_inconsistent    = loopinfo_constructed | loopinfo_inter,

  /** IntRAprocedural control loop information constructed and valid. */
  loopinfo_cf_consistent      = loopinfo_constructed | loopinfo_cf | loopinfo_valid,
  /** IntRAprocedural control loop information constructed and invalid. */
  loopinfo_cf_inconsistent    = loopinfo_constructed | loopinfo_cf,

  /** IntERprocedural control loop information constructed and valid. */
  loopinfo_cf_ip_consistent   = loopinfo_constructed | loopinfo_cf | loopinfo_inter | loopinfo_valid,
  /** IntERprocedural control loop information constructed and invalid. */
  loopinfo_cf_ip_inconsistent = loopinfo_constructed | loopinfo_cf | loopinfo_inter
} irg_loopinfo_state;

/** Return the current loop information state. */
irg_loopinfo_state get_irg_loopinfo_state(const ir_graph *irg);

/** Sets the current loop information state. */
void set_irg_loopinfo_state(ir_graph *irg, irg_loopinfo_state s);

/** Sets the loop information state to the appropriate inconsistent state.
 *  If state is 'none' does not change. */
void set_irg_loopinfo_inconsistent(ir_graph *irg);
/** Sets the loop information state to the appropriate inconsistent state.
 *  If state is 'none' does not change.
 *  Does this for all irgs. */
void set_irp_loopinfo_inconsistent(void);

/** state: callee_information_state
 *  Call nodes contain a list of possible callees.  This list must be
 *  computed by an analysis.
 *
 *  It's strange that this state is administered on irg basis, as the
 *  information must be computed for the whole program, or not?
 */
typedef enum {
  irg_callee_info_none,
  irg_callee_info_consistent,
  irg_callee_info_inconsistent
} irg_callee_info_state;

/** returns the callee_info_state of an IR graph. */
irg_callee_info_state get_irg_callee_info_state(const ir_graph *irg);

/** sets the callee_info_state of an IR graph. */
void                  set_irg_callee_info_state(ir_graph *irg, irg_callee_info_state s);

/** property:
 *  Tells how to handle an ir graph in inlineing.
 */
typedef enum {
  irg_inline_any,         /**< No restriction on inlineing. Default. */
  irg_inline_forbidden,   /**< The graph may not be inlined. */
  irg_inline_recomended,  /**< The graph should be inlined. */
  irg_inline_forced       /**< The graph must be inlined. */
} irg_inline_property;

/** Returns the inline property of a graph. */
irg_inline_property get_irg_inline_property(const ir_graph *irg);
/** Sets the inline property of a graph. */
void set_irg_inline_property(ir_graph *irg, irg_inline_property s);

/** additional graph flags:
 *  Tell about special properties of a graph. Some
 *  of these may be discovered by analyses.
 */
typedef enum {
  irg_const_function    = 0x00000001, /**< This graph did not access memory and calculates
                                         its return values solely from its parameters.
                                         GCC: __attribute__((const)). */
  irg_pure_function     = 0x00000002, /**< This graph did NOT write to memory and calculates
                                         its return values solely form its parameters and
                                         the memory they points to (or global vars).
                                         GCC: __attribute__((pure)). */
  irg_noreturn_function = 0x00000004, /**< This graph did not return due to an aborting system
                                         call.
                                         GCC: __attribute__((noreturn)). */
  irg_nothrow_function  = 0x00000008, /**< This graph cannot throw an exception.
                                         GCC: __attribute__((nothrow)). */
  irg_naked_function    = 0x00000010, /**< This graph is naked.
                                         GCC: __attribute__((naked)). */
  irg_malloc_function   = 0x00000020  /**< This graph returns newly allocate memory.
                                         GCC: __attribute__((malloc)). */
} irg_additional_property;

/** Returns the mask of the additional graph properties. */
unsigned get_irg_additional_properties(const ir_graph *irg);

/** Sets the mask of the additional graph properties. */
void set_irg_additional_properties(ir_graph *irg, unsigned property_mask);

/** Sets one additional graph property. */
void set_irg_additional_property(ir_graph *irg, irg_additional_property flag);

/** A void * field to link arbitrary information to the node. */
void  set_irg_link (ir_graph *irg, void *thing);
void *get_irg_link (const ir_graph *irg);

/** Increments visited flag by one.
 *  @see also: get_irn_visited() get_irg_block_visited(). */
void          inc_irg_visited (ir_graph *irg);
unsigned long get_irg_visited (const ir_graph *irg);
void          set_irg_visited (ir_graph *irg, unsigned long i);
/** An interprocedural flag valid for all irgs.
 *  @see also: get_irn_visited() get_irg_block_visited(). */
unsigned long get_max_irg_visited (void);
void          set_max_irg_visited (int val);
unsigned long inc_max_irg_visited (void);

/** Increments block_visited by one.
 *  @see also: get_irn_visited() get_irg_block_visited(). */
void          inc_irg_block_visited (ir_graph *irg);
unsigned long get_irg_block_visited (const ir_graph *irg);
void          set_irg_block_visited (ir_graph *irg, unsigned long i);

/** move Proj nodes into the same block as its predecessors */
void normalize_proj_nodes(ir_graph *irg);

/** set a description for local value n */
void set_irg_loc_description(ir_graph *irg, int n, void *description);

/** get the description for local value n */
void *get_irg_loc_description(ir_graph *irg, int n);

/**
 * Access custom graph data.
 * The data must have been registered with
 * register_additional_graph_data() before.
 * @param graph The graph to get the data from.
 * @param type The type of the data you registered.
 * @param off The value returned by register_additional_graph_data().
 * @return A pointer of type @p type.
 */
#define get_irg_data(graph,type,off) \
  (assert(off > 0 && "Invalid graph data offset"), (type *) ((char *) (graph) - (off)))

/**
 * Get the pointer to the node some custom data belongs to.
 * @param data The pointer to the custom data.
 * @param off The number as returned by register_additional_graph_data().
 * @return A pointer to the ir node the custom data belongs to.
 */
#define get_irg_data_base(data,off) \
  (assert(off > 0 && "Invalid graph data offset"), (ir_graph *) ((char *) (data) + (off)))

/**
 * Request additional data to be allocated with an ir graph.
 * @param size The size of the additional data required.
 * @return A positive number, if the operation was successful, which
 * must be passed to the access macro get_irg_data(), 0 if the
 * registration failed.
 */
size_t register_additional_graph_data(size_t size);

# endif /* _IRGRAPH_H_ */