1/* Header file for PHI node routines
2   Copyright (C) 2013-2015 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3.  If not see
18<http://www.gnu.org/licenses/>.  */
19
20#ifndef GCC_TREE_PHINODES_H
21#define GCC_TREE_PHINODES_H
22
23extern void phinodes_print_statistics (void);
24extern void release_phi_node (gimple);
25extern void reserve_phi_args_for_new_edge (basic_block);
26extern void add_phi_node_to_bb (gphi *phi, basic_block bb);
27extern gphi *create_phi_node (tree, basic_block);
28extern void add_phi_arg (gphi *, tree, edge, source_location);
29extern void remove_phi_args (edge);
30extern void remove_phi_node (gimple_stmt_iterator *, bool);
31extern void remove_phi_nodes (basic_block);
32extern tree degenerate_phi_result (gphi *);
33extern void set_phi_nodes (basic_block, gimple_seq);
34
35static inline use_operand_p
36gimple_phi_arg_imm_use_ptr (gimple gs, int i)
37{
38  return &gimple_phi_arg (gs, i)->imm_use;
39}
40
41/* Return the phi argument which contains the specified use.  */
42
43static inline int
44phi_arg_index_from_use (use_operand_p use)
45{
46  struct phi_arg_d *element, *root;
47  size_t index;
48  gimple phi;
49
50  /* Since the use is the first thing in a PHI argument element, we can
51     calculate its index based on casting it to an argument, and performing
52     pointer arithmetic.  */
53
54  phi = USE_STMT (use);
55
56  element = (struct phi_arg_d *)use;
57  root = gimple_phi_arg (phi, 0);
58  index = element - root;
59
60  /* Make sure the calculation doesn't have any leftover bytes.  If it does,
61     then imm_use is likely not the first element in phi_arg_d.  */
62  gcc_checking_assert ((((char *)element - (char *)root)
63			% sizeof (struct phi_arg_d)) == 0
64		       && index < gimple_phi_capacity (phi));
65
66 return index;
67}
68
69#endif /* GCC_TREE_PHINODES_H */
70