| /* Data structures and function declarations for the SSA value propagation |
| engine. |
| Copyright (C) 2001, 2003, 2004 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 2, 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 COPYING. If not, write to |
| the Free Software Foundation, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #ifndef _TREE_SSA_PROPAGATE_H |
| #define _TREE_SSA_PROPAGATE_H 1 |
| |
| /* Use the TREE_VISITED bitflag to mark statements and PHI nodes that |
| have been deemed varying and should not be simulated again. */ |
| #define DONT_SIMULATE_AGAIN(T) TREE_VISITED (T) |
| |
| /* 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 |
| }; |
| |
| |
| /* Call-back functions used by the value propagation engine. */ |
| typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (tree, edge *, tree *); |
| typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (tree); |
| |
| void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn); |
| tree get_rhs (tree); |
| bool set_rhs (tree *, tree); |
| |
| #endif /* _TREE_SSA_PROPAGATE_H */ |