Implement filter expression to bytecode compiler in liblttng-ctl
[lttng-tools.git] / src / lib / lttng-ctl / align.h
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1#ifndef _LTTNG_ALIGN_H
2#define _LTTNG_ALIGN_H
3
4/*
5 * align.h
6 *
7 * (C) Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 */
19
20#include <lttng/bug.h>
21#include <unistd.h>
22#include <limits.h>
23
24#ifndef PAGE_SIZE /* Cygwin limits.h defines its own PAGE_SIZE */
25#define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
26#endif
27
28#define PAGE_MASK (~(PAGE_SIZE - 1))
29#define __ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask))
30#define ALIGN(v, align) __ALIGN_MASK(v, (__typeof__(v)) (align) - 1)
31#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
32
33/**
34 * offset_align - Calculate the offset needed to align an object on its natural
35 * alignment towards higher addresses.
36 * @align_drift: object offset from an "alignment"-aligned address.
37 * @alignment: natural object alignment. Must be non-zero, power of 2.
38 *
39 * Returns the offset that must be added to align towards higher
40 * addresses.
41 */
42#define offset_align(align_drift, alignment) \
43 ({ \
44 LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \
45 || ((alignment) & ((alignment) - 1))); \
46 (((alignment) - (align_drift)) & ((alignment) - 1)); \
47 })
48
49/**
50 * offset_align_floor - Calculate the offset needed to align an object
51 * on its natural alignment towards lower addresses.
52 * @align_drift: object offset from an "alignment"-aligned address.
53 * @alignment: natural object alignment. Must be non-zero, power of 2.
54 *
55 * Returns the offset that must be substracted to align towards lower addresses.
56 */
57#define offset_align_floor(align_drift, alignment) \
58 ({ \
59 LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \
60 || ((alignment) & ((alignment) - 1))); \
61 (((align_drift) - (alignment)) & ((alignment) - 1); \
62 })
63
64#endif /* _LTTNG_ALIGN_H */
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