projects / librseq.git / blame
| Commit | Line | Data |
|---|---|---|
| 19be9217 MD |
1 | // SPDX-License-Identifier: MIT |
| 2 | // SPDX-FileCopyrightText: 2024 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 3 | ||
| c3fad074 MD |
4 | #ifndef _RSEQ_COMMON_UTILS_H |
| 5 | #define _RSEQ_COMMON_UTILS_H | |
| 6 | ||
| 7 | #include <stdbool.h> | |
| 8 | #include <stdint.h> | |
| 19be9217 | 9 | |
| 57d8b586 OD |
10 | #define RSEQ_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) |
| 11 | ||
| 19be9217 MD |
12 | #define __rseq_align_mask(v, mask) (((v) + (mask)) & ~(mask)) |
| 13 | #define rseq_align(v, align) __rseq_align_mask(v, (__typeof__(v)) (align) - 1) | |
| 14 | ||
| 15 | static inline | |
| 16 | unsigned int rseq_fls_u64(uint64_t x) | |
| 17 | { | |
| 18 | unsigned int r = 64; | |
| 19 | ||
| 20 | if (!x) | |
| 21 | return 0; | |
| 22 | ||
| 23 | if (!(x & 0xFFFFFFFF00000000ULL)) { | |
| 24 | x <<= 32; | |
| 25 | r -= 32; | |
| 26 | } | |
| 27 | if (!(x & 0xFFFF000000000000ULL)) { | |
| 28 | x <<= 16; | |
| 29 | r -= 16; | |
| 30 | } | |
| 31 | if (!(x & 0xFF00000000000000ULL)) { | |
| 32 | x <<= 8; | |
| 33 | r -= 8; | |
| 34 | } | |
| 35 | if (!(x & 0xF000000000000000ULL)) { | |
| 36 | x <<= 4; | |
| 37 | r -= 4; | |
| 38 | } | |
| 39 | if (!(x & 0xC000000000000000ULL)) { | |
| 40 | x <<= 2; | |
| 41 | r -= 2; | |
| 42 | } | |
| 43 | if (!(x & 0x8000000000000000ULL)) { | |
| 44 | x <<= 1; | |
| 45 | r -= 1; | |
| 46 | } | |
| 47 | return r; | |
| 48 | } | |
| 49 | ||
| 50 | static inline | |
| 51 | unsigned int rseq_fls_u32(uint32_t x) | |
| 52 | { | |
| 53 | unsigned int r = 32; | |
| 54 | ||
| 55 | if (!x) | |
| 56 | return 0; | |
| 57 | if (!(x & 0xFFFF0000U)) { | |
| 58 | x <<= 16; | |
| 59 | r -= 16; | |
| 60 | } | |
| 61 | if (!(x & 0xFF000000U)) { | |
| 62 | x <<= 8; | |
| 63 | r -= 8; | |
| 64 | } | |
| 65 | if (!(x & 0xF0000000U)) { | |
| 66 | x <<= 4; | |
| 67 | r -= 4; | |
| 68 | } | |
| 69 | if (!(x & 0xC0000000U)) { | |
| 70 | x <<= 2; | |
| 71 | r -= 2; | |
| 72 | } | |
| 73 | if (!(x & 0x80000000U)) { | |
| 74 | x <<= 1; | |
| 75 | r -= 1; | |
| 76 | } | |
| 77 | return r; | |
| 78 | } | |
| 79 | ||
| 80 | static inline | |
| 81 | unsigned int rseq_fls_ulong(unsigned long x) | |
| 82 | { | |
| 83 | #if RSEQ_BITS_PER_LONG == 32 | |
| 84 | return rseq_fls_u32(x); | |
| 85 | #else | |
| 86 | return rseq_fls_u64(x); | |
| 87 | #endif | |
| 88 | } | |
| 89 | ||
| 90 | /* | |
| 91 | * Return the minimum order for which x <= (1UL << order). | |
| 92 | * Return -1 if x is 0. | |
| 93 | */ | |
| 94 | static inline | |
| 95 | int rseq_get_count_order_ulong(unsigned long x) | |
| 96 | { | |
| 97 | if (!x) | |
| 98 | return -1; | |
| 99 | ||
| 100 | return rseq_fls_ulong(x - 1); | |
| 101 | } | |
| 102 | ||
| 103 | #define RSEQ_DEFAULT_PAGE_SIZE 4096 | |
| 104 | ||
| 105 | static inline | |
| f2981623 | 106 | unsigned long rseq_get_page_len(void) |
| 19be9217 MD |
107 | { |
| 108 | long page_len = sysconf(_SC_PAGE_SIZE); | |
| 109 | ||
| 110 | if (page_len < 0) | |
| 111 | page_len = RSEQ_DEFAULT_PAGE_SIZE; | |
| f2981623 | 112 | return (unsigned long) page_len; |
| 19be9217 MD |
113 | } |
| 114 | ||
| 9649c7ee MD |
115 | static inline |
| 116 | int rseq_hweight_ulong(unsigned long v) | |
| 117 | { | |
| d9b46e1c | 118 | return __builtin_popcountl(v); |
| 9649c7ee MD |
119 | } |
| 120 | ||
| f2981623 MD |
121 | static inline |
| 122 | bool is_pow2(uint64_t x) | |
| 123 | { | |
| 124 | return !(x & (x - 1)); | |
| 125 | } | |
| 126 | ||
| 127 | /* | |
| 128 | * Calculate offset needed to align p on alignment towards higher | |
| 129 | * addresses. Alignment must be a power of 2 | |
| 130 | */ | |
| 131 | static inline | |
| 132 | off_t offset_align(uintptr_t p, size_t alignment) | |
| 133 | { | |
| 134 | return (alignment - p) & (alignment - 1); | |
| 135 | } | |
| 136 | ||
| c3fad074 | 137 | #endif /* _RSEQ_COMMON_UTILS_H */ |