1/* Data structures and function declarations for the SSA value propagation 2 engine. 3 Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc. 4 Contributed by Diego Novillo <dnovillo@redhat.com> 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify 9it under the terms of the GNU General Public License as published by 10the Free Software Foundation; either version 3, or (at your option) 11any later version. 12 13GCC is distributed in the hope that it will be useful, 14but WITHOUT ANY WARRANTY; without even the implied warranty of 15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16GNU General Public License for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING3. If not see 20<http://www.gnu.org/licenses/>. */ 21 22#ifndef _TREE_SSA_PROPAGATE_H 23#define _TREE_SSA_PROPAGATE_H 1 24 25/* If SIM_P is true, statement S will be simulated again. */ 26 27static inline void 28prop_set_simulate_again (gimple s, bool visit_p) 29{ 30 gimple_set_visited (s, visit_p); 31} 32 33/* Return true if statement T should be simulated again. */ 34 35static inline bool 36prop_simulate_again_p (gimple s) 37{ 38 return gimple_visited_p (s); 39} 40 41/* Lattice values used for propagation purposes. Specific instances 42 of a propagation engine must return these values from the statement 43 and PHI visit functions to direct the engine. */ 44enum ssa_prop_result { 45 /* The statement produces nothing of interest. No edges will be 46 added to the work lists. */ 47 SSA_PROP_NOT_INTERESTING, 48 49 /* The statement produces an interesting value. The set SSA_NAMEs 50 returned by SSA_PROP_VISIT_STMT should be added to 51 INTERESTING_SSA_EDGES. If the statement being visited is a 52 conditional jump, SSA_PROP_VISIT_STMT should indicate which edge 53 out of the basic block should be marked executable. */ 54 SSA_PROP_INTERESTING, 55 56 /* The statement produces a varying (i.e., useless) value and 57 should not be simulated again. If the statement being visited 58 is a conditional jump, all the edges coming out of the block 59 will be considered executable. */ 60 SSA_PROP_VARYING 61}; 62 63 64struct prop_value_d { 65 /* Lattice value. Each propagator is free to define its own 66 lattice and this field is only meaningful while propagating. 67 It will not be used by substitute_and_fold. */ 68 unsigned lattice_val; 69 70 /* Propagated value. */ 71 tree value; 72}; 73 74typedef struct prop_value_d prop_value_t; 75 76 77/* Type of value ranges. See value_range_d for a description of these 78 types. */ 79enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING }; 80 81/* Range of values that can be associated with an SSA_NAME after VRP 82 has executed. */ 83struct value_range_d 84{ 85 /* Lattice value represented by this range. */ 86 enum value_range_type type; 87 88 /* Minimum and maximum values represented by this range. These 89 values should be interpreted as follows: 90 91 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must 92 be NULL. 93 94 - If TYPE == VR_RANGE then MIN holds the minimum value and 95 MAX holds the maximum value of the range [MIN, MAX]. 96 97 - If TYPE == ANTI_RANGE the variable is known to NOT 98 take any values in the range [MIN, MAX]. */ 99 tree min; 100 tree max; 101 102 /* Set of SSA names whose value ranges are equivalent to this one. 103 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */ 104 bitmap equiv; 105}; 106 107typedef struct value_range_d value_range_t; 108 109 110/* Call-back functions used by the value propagation engine. */ 111typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (gimple, edge *, tree *); 112typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (gimple); 113typedef bool (*ssa_prop_fold_stmt_fn) (gimple_stmt_iterator *gsi); 114 115 116/* In tree-ssa-propagate.c */ 117void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn); 118bool valid_gimple_rhs_p (tree); 119bool valid_gimple_call_p (tree); 120void move_ssa_defining_stmt_for_defs (gimple, gimple); 121bool update_call_from_tree (gimple_stmt_iterator *, tree); 122bool stmt_makes_single_store (gimple); 123bool substitute_and_fold (prop_value_t *, ssa_prop_fold_stmt_fn, bool); 124 125#endif /* _TREE_SSA_PROPAGATE_H */ 126