projects / babeltrace.git / blame
| Commit | Line | Data |
|---|---|---|
| d79865b9 MD |
1 | #ifndef _BABELTRACE_ALIGN_H |
| 2 | #define _BABELTRACE_ALIGN_H | |
| 6dc2ca62 | 3 | |
| de0ba614 | 4 | /* |
| d79865b9 | 5 | * BabelTrace align.h - alignment header |
| de0ba614 | 6 | * |
| ccd7e1c8 | 7 | * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| de0ba614 | 8 | * |
| ccd7e1c8 MD |
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: | |
| de0ba614 | 15 | * |
| ccd7e1c8 MD |
16 | * The above copyright notice and this permission notice shall be included in |
| 17 | * all copies or substantial portions of the Software. | |
| de0ba614 MD |
18 | */ |
| 19 | ||
| 4c8bfb7e | 20 | #include <babeltrace/compiler.h> |
| 6dc2ca62 MD |
21 | |
| 22 | #define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a) - 1) | |
| 23 | #define __ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) | |
| 24 | #define PTR_ALIGN(p, a) ((typeof(p)) ALIGN((unsigned long) (p), a)) | |
| 25 | #define ALIGN_FLOOR(x, a) __ALIGN_FLOOR_MASK(x, (typeof(x)) (a) - 1) | |
| 26 | #define __ALIGN_FLOOR_MASK(x, mask) ((x) & ~(mask)) | |
| 27 | #define PTR_ALIGN_FLOOR(p, a) \ | |
| 28 | ((typeof(p)) ALIGN_FLOOR((unsigned long) (p), a)) | |
| 29 | #define IS_ALIGNED(x, a) (((x) & ((typeof(x)) (a) - 1)) == 0) | |
| 30 | ||
| 31 | /* | |
| 32 | * Align pointer on natural object alignment. | |
| 33 | */ | |
| 34 | #define object_align(obj) PTR_ALIGN(obj, __alignof__(*(obj))) | |
| 35 | #define object_align_floor(obj) PTR_ALIGN_FLOOR(obj, __alignof__(*(obj))) | |
| 36 | ||
| 37 | /** | |
| 38 | * offset_align - Calculate the offset needed to align an object on its natural | |
| 39 | * alignment towards higher addresses. | |
| 40 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 41 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 42 | * | |
| 43 | * Returns the offset that must be added to align towards higher | |
| 44 | * addresses. | |
| 45 | */ | |
| 46 | #define offset_align(align_drift, alignment) \ | |
| 47 | ({ \ | |
| 48 | MAYBE_BUILD_BUG_ON((alignment) == 0 \ | |
| 49 | || ((alignment) & ((alignment) - 1))); \ | |
| 50 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
| 51 | }) | |
| 52 | ||
| 53 | /** | |
| 54 | * offset_align_floor - Calculate the offset needed to align an object | |
| 55 | * on its natural alignment towards lower addresses. | |
| 56 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 57 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 58 | * | |
| 59 | * Returns the offset that must be substracted to align towards lower addresses. | |
| 60 | */ | |
| 61 | #define offset_align_floor(align_drift, alignment) \ | |
| 62 | ({ \ | |
| 63 | MAYBE_BUILD_BUG_ON((alignment) == 0 \ | |
| 64 | || ((alignment) & ((alignment) - 1))); \ | |
| 65 | (((align_drift) - (alignment)) & ((alignment) - 1); \ | |
| 66 | }) | |
| 67 | ||
| d79865b9 | 68 | #endif /* _BABELTRACE_ALIGN_H */ |