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1 | #ifndef _BABELTRACE_ALIGN_H |
2 | #define _BABELTRACE_ALIGN_H | |
6dc2ca62 | 3 | |
de0ba614 | 4 | /* |
d79865b9 | 5 | * BabelTrace align.h - alignment header |
de0ba614 MD |
6 | * |
7 | * Copyright (c) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | */ | |
23 | ||
6dc2ca62 MD |
24 | #include <ctf/compiler.h> |
25 | ||
26 | #define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a) - 1) | |
27 | #define __ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) | |
28 | #define PTR_ALIGN(p, a) ((typeof(p)) ALIGN((unsigned long) (p), a)) | |
29 | #define ALIGN_FLOOR(x, a) __ALIGN_FLOOR_MASK(x, (typeof(x)) (a) - 1) | |
30 | #define __ALIGN_FLOOR_MASK(x, mask) ((x) & ~(mask)) | |
31 | #define PTR_ALIGN_FLOOR(p, a) \ | |
32 | ((typeof(p)) ALIGN_FLOOR((unsigned long) (p), a)) | |
33 | #define IS_ALIGNED(x, a) (((x) & ((typeof(x)) (a) - 1)) == 0) | |
34 | ||
35 | /* | |
36 | * Align pointer on natural object alignment. | |
37 | */ | |
38 | #define object_align(obj) PTR_ALIGN(obj, __alignof__(*(obj))) | |
39 | #define object_align_floor(obj) PTR_ALIGN_FLOOR(obj, __alignof__(*(obj))) | |
40 | ||
41 | /** | |
42 | * offset_align - Calculate the offset needed to align an object on its natural | |
43 | * alignment towards higher addresses. | |
44 | * @align_drift: object offset from an "alignment"-aligned address. | |
45 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
46 | * | |
47 | * Returns the offset that must be added to align towards higher | |
48 | * addresses. | |
49 | */ | |
50 | #define offset_align(align_drift, alignment) \ | |
51 | ({ \ | |
52 | MAYBE_BUILD_BUG_ON((alignment) == 0 \ | |
53 | || ((alignment) & ((alignment) - 1))); \ | |
54 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
55 | }) | |
56 | ||
57 | /** | |
58 | * offset_align_floor - Calculate the offset needed to align an object | |
59 | * on its natural alignment towards lower addresses. | |
60 | * @align_drift: object offset from an "alignment"-aligned address. | |
61 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
62 | * | |
63 | * Returns the offset that must be substracted to align towards lower addresses. | |
64 | */ | |
65 | #define offset_align_floor(align_drift, alignment) \ | |
66 | ({ \ | |
67 | MAYBE_BUILD_BUG_ON((alignment) == 0 \ | |
68 | || ((alignment) & ((alignment) - 1))); \ | |
69 | (((align_drift) - (alignment)) & ((alignment) - 1); \ | |
70 | }) | |
71 | ||
d79865b9 | 72 | #endif /* _BABELTRACE_ALIGN_H */ |