1/* Routines for expanding from SSA form to RTL.
2   Copyright (C) 2009-2020 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 3, or (at your option)
9any later version.
10
11GCC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14GNU General Public License 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
21#ifndef GCC_TREE_OUTOF_SSA_H
22#define GCC_TREE_OUTOF_SSA_H
23
24
25/* This structure (of which only a singleton SA exists) is used to
26   pass around information between the outof-SSA functions, cfgexpand
27   and expand itself.  */
28struct ssaexpand
29{
30  /* The computed partitions of SSA names are stored here.  */
31  var_map map;
32
33  /* For an SSA name version V bit V is set iff TER decided that
34     its definition should be forwarded.  */
35  bitmap values;
36
37  /* For a partition number I partition_to_pseudo[I] contains the
38     RTL expression of the allocated space of it (either a MEM or
39     a pseudos REG).  */
40  rtx *partition_to_pseudo;
41
42  /* If partition I contains an SSA name that has a default def for a
43     parameter, bit I will be set in this bitmap.  */
44  bitmap partitions_for_parm_default_defs;
45
46  /* If partition I contains an SSA name that has an undefined value,
47     bit I will be set in this bitmap.  */
48  bitmap partitions_for_undefined_values;
49};
50
51/* This is the singleton described above.  */
52extern struct ssaexpand SA;
53
54/* Returns the RTX expression representing the storage of the outof-SSA
55   partition that the SSA name EXP is a member of.  */
56static inline rtx
57get_rtx_for_ssa_name (tree exp)
58{
59  int p = partition_find (SA.map->var_partition, SSA_NAME_VERSION (exp));
60  if (SA.map->partition_to_view)
61    p = SA.map->partition_to_view[p];
62  gcc_assert (p != NO_PARTITION);
63  return SA.partition_to_pseudo[p];
64}
65
66/* If TER decided to forward the definition of SSA name EXP this function
67   returns the defining statement, otherwise NULL.  */
68static inline gimple *
69get_gimple_for_ssa_name (tree exp)
70{
71  int v = SSA_NAME_VERSION (exp);
72  if (SA.values && bitmap_bit_p (SA.values, v))
73    return SSA_NAME_DEF_STMT (exp);
74  return NULL;
75}
76
77extern bool ssa_is_replaceable_p (gimple *stmt);
78extern void finish_out_of_ssa (struct ssaexpand *sa);
79extern unsigned int rewrite_out_of_ssa (struct ssaexpand *sa);
80extern void expand_phi_nodes (struct ssaexpand *sa);
81
82#endif /* GCC_TREE_OUTOF_SSA_H */
83