1 /* Data structures and function declarations for the SSA value propagation 2 engine. 3 Copyright (C) 2004-2018 Free Software Foundation, Inc. 4 Contributed by Diego Novillo <dnovillo@redhat.com> 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3, or (at your option) 11 any later version. 12 13 GCC is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along 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 27 static inline void 28 prop_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 35 static inline bool 36 prop_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. */ 44 enum 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 64 extern bool valid_gimple_rhs_p (tree); 65 extern void move_ssa_defining_stmt_for_defs (gimple *, gimple *); 66 extern bool update_gimple_call (gimple_stmt_iterator *, tree, int, ...); 67 extern bool update_call_from_tree (gimple_stmt_iterator *, tree); 68 extern bool stmt_makes_single_store (gimple *); 69 extern bool may_propagate_copy (tree, tree); 70 extern bool may_propagate_copy_into_stmt (gimple *, tree); 71 extern bool may_propagate_copy_into_asm (tree); 72 extern void propagate_value (use_operand_p, tree); 73 extern void replace_exp (use_operand_p, tree); 74 extern void propagate_tree_value (tree *, tree); 75 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree); 76 77 /* Public interface into the SSA propagation engine. Clients should inherit 78 from this class and provide their own visitors. */ 79 80 class ssa_propagation_engine 81 { 82 public: 83 84 virtual ~ssa_propagation_engine (void) { } 85 86 /* Virtual functions the clients must provide to visit statements 87 and phi nodes respectively. */ 88 virtual enum ssa_prop_result visit_stmt (gimple *, edge *, tree *) = 0; 89 virtual enum ssa_prop_result visit_phi (gphi *) = 0; 90 91 /* Main interface into the propagation engine. */ 92 void ssa_propagate (void); 93 94 private: 95 /* Internal implementation details. */ 96 void simulate_stmt (gimple *stmt); 97 void simulate_block (basic_block); 98 }; 99 100 class substitute_and_fold_engine 101 { 102 public: 103 virtual ~substitute_and_fold_engine (void) { } 104 virtual bool fold_stmt (gimple_stmt_iterator *) { return false; } 105 virtual tree get_value (tree) { return NULL_TREE; } 106 107 bool substitute_and_fold (void); 108 bool replace_uses_in (gimple *); 109 bool replace_phi_args_in (gphi *); 110 }; 111 112 #endif /* _TREE_SSA_PROPAGATE_H */ 113