/* Data structures and function declarations for the SSA value propagation | |

engine. | |

Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc. | |

Contributed by Diego Novillo <dnovillo@redhat.com> | |

This file is part of GCC. | |

GCC 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 3, or (at your option) | |

any later version. | |

GCC 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 GCC; see the file COPYING3. If not see | |

<http://www.gnu.org/licenses/>. */ | |

#ifndef _TREE_SSA_PROPAGATE_H | |

#define _TREE_SSA_PROPAGATE_H 1 | |

/* If SIM_P is true, statement S will be simulated again. */ | |

static inline void | |

prop_set_simulate_again (gimple s, bool visit_p) | |

{ | |

gimple_set_visited (s, visit_p); | |

} | |

/* Return true if statement T should be simulated again. */ | |

static inline bool | |

prop_simulate_again_p (gimple s) | |

{ | |

return gimple_visited_p (s); | |

} | |

/* Lattice values used for propagation purposes. Specific instances | |

of a propagation engine must return these values from the statement | |

and PHI visit functions to direct the engine. */ | |

enum ssa_prop_result { | |

/* The statement produces nothing of interest. No edges will be | |

added to the work lists. */ | |

SSA_PROP_NOT_INTERESTING, | |

/* The statement produces an interesting value. The set SSA_NAMEs | |

returned by SSA_PROP_VISIT_STMT should be added to | |

INTERESTING_SSA_EDGES. If the statement being visited is a | |

conditional jump, SSA_PROP_VISIT_STMT should indicate which edge | |

out of the basic block should be marked executable. */ | |

SSA_PROP_INTERESTING, | |

/* The statement produces a varying (i.e., useless) value and | |

should not be simulated again. If the statement being visited | |

is a conditional jump, all the edges coming out of the block | |

will be considered executable. */ | |

SSA_PROP_VARYING | |

}; | |

struct prop_value_d { | |

/* Lattice value. Each propagator is free to define its own | |

lattice and this field is only meaningful while propagating. | |

It will not be used by substitute_and_fold. */ | |

unsigned lattice_val; | |

/* Propagated value. */ | |

tree value; | |

}; | |

typedef struct prop_value_d prop_value_t; | |

/* Type of value ranges. See value_range_d for a description of these | |

types. */ | |

enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING }; | |

/* Range of values that can be associated with an SSA_NAME after VRP | |

has executed. */ | |

struct value_range_d | |

{ | |

/* Lattice value represented by this range. */ | |

enum value_range_type type; | |

/* Minimum and maximum values represented by this range. These | |

values should be interpreted as follows: | |

- If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must | |

be NULL. | |

- If TYPE == VR_RANGE then MIN holds the minimum value and | |

MAX holds the maximum value of the range [MIN, MAX]. | |

- If TYPE == ANTI_RANGE the variable is known to NOT | |

take any values in the range [MIN, MAX]. */ | |

tree min; | |

tree max; | |

/* Set of SSA names whose value ranges are equivalent to this one. | |

This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */ | |

bitmap equiv; | |

}; | |

typedef struct value_range_d value_range_t; | |

/* Call-back functions used by the value propagation engine. */ | |

typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (gimple, edge *, tree *); | |

typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (gimple); | |

/* In tree-ssa-propagate.c */ | |

void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn); | |

bool valid_gimple_rhs_p (tree); | |

bool valid_gimple_call_p (tree); | |

void move_ssa_defining_stmt_for_defs (gimple, gimple); | |

bool update_call_from_tree (gimple_stmt_iterator *, tree); | |

bool stmt_makes_single_load (gimple); | |

bool stmt_makes_single_store (gimple); | |

bool substitute_and_fold (prop_value_t *, bool); | |

#endif /* _TREE_SSA_PROPAGATE_H */ |