diff options
Diffstat (limited to 'vendor/github.com/mitjafelicijan/go-tree-sitter/bits.h')
| -rw-r--r-- | vendor/github.com/mitjafelicijan/go-tree-sitter/bits.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/vendor/github.com/mitjafelicijan/go-tree-sitter/bits.h b/vendor/github.com/mitjafelicijan/go-tree-sitter/bits.h new file mode 100644 index 0000000..ca8caf3 --- /dev/null +++ b/vendor/github.com/mitjafelicijan/go-tree-sitter/bits.h | |||
| @@ -0,0 +1,42 @@ | |||
| 1 | #ifndef TREE_SITTER_BITS_H_ | ||
| 2 | #define TREE_SITTER_BITS_H_ | ||
| 3 | |||
| 4 | #include <stdint.h> | ||
| 5 | |||
| 6 | static inline uint32_t bitmask_for_index(uint16_t id) { | ||
| 7 | return (1u << (31 - id)); | ||
| 8 | } | ||
| 9 | |||
| 10 | #ifdef __TINYC__ | ||
| 11 | |||
| 12 | // Algorithm taken from the Hacker's Delight book | ||
| 13 | // See also https://graphics.stanford.edu/~seander/bithacks.html | ||
| 14 | static inline uint32_t count_leading_zeros(uint32_t x) { | ||
| 15 | int count = 0; | ||
| 16 | if (x == 0) return 32; | ||
| 17 | x = x - ((x >> 1) & 0x55555555); | ||
| 18 | x = (x & 0x33333333) + ((x >> 2) & 0x33333333); | ||
| 19 | count = (((x + (x >> 4)) & 0x0f0f0f0f) * 0x01010101) >> 24; | ||
| 20 | return count; | ||
| 21 | } | ||
| 22 | |||
| 23 | #elif defined _WIN32 && !defined __GNUC__ | ||
| 24 | |||
| 25 | #include <intrin.h> | ||
| 26 | |||
| 27 | static inline uint32_t count_leading_zeros(uint32_t x) { | ||
| 28 | if (x == 0) return 32; | ||
| 29 | uint32_t result; | ||
| 30 | _BitScanReverse(&result, x); | ||
| 31 | return 31 - result; | ||
| 32 | } | ||
| 33 | |||
| 34 | #else | ||
| 35 | |||
| 36 | static inline uint32_t count_leading_zeros(uint32_t x) { | ||
| 37 | if (x == 0) return 32; | ||
| 38 | return __builtin_clz(x); | ||
| 39 | } | ||
| 40 | |||
| 41 | #endif | ||
| 42 | #endif // TREE_SITTER_BITS_H_ | ||
