1/* Alignment-related classes.
2 Copyright (C) 2018-2023 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
14for 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/* Align flags tuple with alignment in log form and with a maximum skip. */
21
22struct align_flags_tuple
23{
24 /* Values of the -falign-* flags: how much to align labels in code.
25 log is "align to 2^log" (so 0 means no alignment).
26 maxskip is the maximum allowed amount of padding to insert. */
27 int log;
28 int maxskip;
29
30 /* Normalize filled values so that maxskip is not bigger than 1 << log. */
31 void normalize ()
32 {
33 int n = (1 << log);
34 if (maxskip > n)
35 maxskip = n - 1;
36 }
37
38 /* Return original value of an alignment flag. */
39 int get_value ()
40 {
41 return maxskip + 1;
42 }
43};
44
45/* Alignment flags is structure used as value of -align-* options.
46 It's used in target-dependant code. */
47
48class align_flags
49{
50public:
51 /* Default constructor. */
52 align_flags (int log0 = 0, int maxskip0 = 0, int log1 = 0, int maxskip1 = 0)
53 {
54 levels[0].log = log0;
55 levels[0].maxskip = maxskip0;
56 levels[1].log = log1;
57 levels[1].maxskip = maxskip1;
58 normalize ();
59 }
60
61 /* Normalize both components of align_flags. */
62 void normalize ()
63 {
64 for (unsigned i = 0; i < 2; i++)
65 levels[i].normalize ();
66 }
67
68 /* Get alignment that is common bigger alignment of alignments F0 and F1. */
69 static align_flags max (const align_flags f0, const align_flags f1)
70 {
71 int log0 = MAX (f0.levels[0].log, f1.levels[0].log);
72 int maxskip0 = MAX (f0.levels[0].maxskip, f1.levels[0].maxskip);
73 int log1 = MAX (f0.levels[1].log, f1.levels[1].log);
74 int maxskip1 = MAX (f0.levels[1].maxskip, f1.levels[1].maxskip);
75 return align_flags (log0, maxskip0, log1, maxskip1);
76 }
77
78 align_flags_tuple levels[2];
79};
80
81/* Define maximum supported code alignment. */
82#define MAX_CODE_ALIGN 16
83#define MAX_CODE_ALIGN_VALUE (1 << MAX_CODE_ALIGN)
84

source code of gcc/align.h