1 | /* Header file for SSA loop optimizations. |
2 | Copyright (C) 2013-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #ifndef GCC_TREE_SSA_LOOP_H |
21 | #define GCC_TREE_SSA_LOOP_H |
22 | |
23 | |
24 | /* Affine iv. */ |
25 | |
26 | struct affine_iv |
27 | { |
28 | /* Iv = BASE + STEP * i. */ |
29 | tree base, step; |
30 | |
31 | /* True if this iv does not overflow. */ |
32 | bool no_overflow; |
33 | }; |
34 | |
35 | /* Description of number of iterations of a loop. All the expressions inside |
36 | the structure can be evaluated at the end of the loop's preheader |
37 | (and due to ssa form, also anywhere inside the body of the loop). */ |
38 | |
39 | class tree_niter_desc |
40 | { |
41 | public: |
42 | tree assumptions; /* The boolean expression. If this expression evaluates |
43 | to false, then the other fields in this structure |
44 | should not be used; there is no guarantee that they |
45 | will be correct. */ |
46 | tree may_be_zero; /* The boolean expression. If it evaluates to true, |
47 | the loop will exit in the first iteration (i.e. |
48 | its latch will not be executed), even if the niter |
49 | field says otherwise. */ |
50 | tree niter; /* The expression giving the number of iterations of |
51 | a loop (provided that assumptions == true and |
52 | may_be_zero == false), more precisely the number |
53 | of executions of the latch of the loop. */ |
54 | widest_int max; /* The upper bound on the number of iterations of |
55 | the loop. If niter is constant, then these values |
56 | must agree. */ |
57 | |
58 | /* The simplified shape of the exit condition. This information is used by |
59 | loop unrolling. If CMP is ERROR_MARK, then the loop cannot be unrolled. |
60 | Otherwise, the loop exits if CONTROL CMP BOUND is false, where CMP is one |
61 | of NE_EXPR, LT_EXPR, or GT_EXPR, and CONTROL.STEP is positive if CMP is |
62 | LT_EXPR and negative if CMP is GT_EXPR. */ |
63 | affine_iv control; |
64 | tree bound; |
65 | enum tree_code cmp; |
66 | }; |
67 | |
68 | extern bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *); |
69 | extern char *get_lsm_tmp_name (tree ref, unsigned n, const char *suffix = NULL); |
70 | extern unsigned tree_num_loop_insns (class loop *, struct eni_weights *); |
71 | |
72 | /* Returns the loop of the statement STMT. */ |
73 | |
74 | inline class loop * |
75 | loop_containing_stmt (gimple *stmt) |
76 | { |
77 | basic_block bb = gimple_bb (g: stmt); |
78 | if (!bb) |
79 | return NULL; |
80 | |
81 | return bb->loop_father; |
82 | } |
83 | |
84 | #endif /* GCC_TREE_SSA_LOOP_H */ |
85 | |