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953192ba | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
953192ba | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: MIT |
953192ba | 5 | * |
953192ba MD |
6 | */ |
7 | ||
ab5be9fa MJ |
8 | #ifndef _LTTNG_ALIGN_H |
9 | #define _LTTNG_ALIGN_H | |
10 | ||
c9e313bc | 11 | #include "bug.hpp" |
d575a7f8 | 12 | |
1cbd136b MJ |
13 | /* |
14 | * Align value to the next multiple of align. Returns val if it already is a | |
15 | * multiple of align. Align must be a power of two. | |
16 | */ | |
17 | #define __lttng_align_ceil_mask(v, mask) (((v) + (mask)) & ~(mask)) | |
d575a7f8 | 18 | |
1cbd136b MJ |
19 | #define lttng_align_ceil(v, align) \ |
20 | __lttng_align_ceil_mask(v, (__typeof__(v)) (align) - 1) | |
d4ad24a3 | 21 | |
1cbd136b MJ |
22 | /* |
23 | * Align value to the previous multiple of align. Returns val if it already is a | |
24 | * multiple of align. Align must be a power of two. | |
25 | */ | |
26 | #define __lttng_align_floor_mask(v, mask) ((v) & ~(mask)) | |
d4ad24a3 | 27 | |
1cbd136b MJ |
28 | #define lttng_align_floor(v, align) \ |
29 | __lttng_align_floor_mask(v, (__typeof__(v)) (align) - 1) | |
953192ba MD |
30 | |
31 | /** | |
1cbd136b | 32 | * lttng_offset_align - Calculate the offset needed to align an object on its natural |
953192ba MD |
33 | * alignment towards higher addresses. |
34 | * @align_drift: object offset from an "alignment"-aligned address. | |
35 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
36 | * | |
37 | * Returns the offset that must be added to align towards higher | |
38 | * addresses. | |
39 | */ | |
1cbd136b | 40 | #define lttng_offset_align(align_drift, alignment) \ |
953192ba MD |
41 | ({ \ |
42 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
43 | || ((alignment) & ((alignment) - 1))); \ | |
44 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
45 | }) | |
46 | ||
47 | /** | |
1cbd136b | 48 | * lttng_offset_align_floor - Calculate the offset needed to align an object |
953192ba MD |
49 | * on its natural alignment towards lower addresses. |
50 | * @align_drift: object offset from an "alignment"-aligned address. | |
51 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
52 | * | |
53 | * Returns the offset that must be substracted to align towards lower addresses. | |
54 | */ | |
1cbd136b | 55 | #define lttng_offset_align_floor(align_drift, alignment) \ |
953192ba MD |
56 | ({ \ |
57 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
58 | || ((alignment) & ((alignment) - 1))); \ | |
d07ceecd | 59 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
953192ba MD |
60 | }) |
61 | ||
62 | #endif /* _LTTNG_ALIGN_H */ |