diff options
Diffstat (limited to 'common/bits.c')
| -rw-r--r-- | common/bits.c | 62 |
1 files changed, 0 insertions, 62 deletions
diff --git a/common/bits.c b/common/bits.c deleted file mode 100644 index 6462d21..0000000 --- a/common/bits.c +++ /dev/null @@ -1,62 +0,0 @@ -/* SPDX-License-Identifier: copyleft-next-0.3.1 */ -/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */ - -/** - * @file bits.c - * Bit manipulation helper implementations, currently just byte swaps. - */ - -#include <kmi/types.h> -#include <kmi/attrs.h> -#include <kmi/bits.h> -#include <kmi/builtin.h> - -#undef __bswap16 -__weak uint16_t __bswap16(const uint16_t u) -{ - return (u & 0xff00) >> 8 | (u & 0x00ff) << 8; -} - -#undef __bswap32 -__weak uint32_t __bswap32(const uint32_t u) -{ - return (u & 0xff000000) >> 24 | (u & 0x00ff0000) >> 8 | - (u & 0x0000ff00) << 8 | (u & 0x000000ff) << 24; -} - -#undef __bswap64 -__weak uint64_t __bswap64(const uint64_t u) -{ - return (u & 0xff00000000000000ULL) >> 56 | - (u & 0x00ff000000000000ULL) >> 40 | - (u & 0x0000ff0000000000ULL) >> 24 | - (u & 0x000000ff00000000ULL) >> 8 | - (u & 0x00000000ff000000ULL) << 8 | - (u & 0x0000000000ff0000ULL) << 24 | - (u & 0x000000000000ff00ULL) << 40 | - (u & 0x00000000000000ffULL) << 56; -} - -#undef ffs -__weak int ffs(int v) -{ - /* http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightParallel */ - if (v == 0) - return 0; - - /* silence ubsan warning */ - if (v == INT_MIN) - return 32; - - int c = 32; - v &= -v; - - if (v) c--; - if (v & 0x0000FFFF) c -= 16; - if (v & 0x00FF00FF) c -= 8; - if (v & 0x0F0F0F0F) c -= 4; - if (v & 0x33333333) c -= 2; - if (v & 0x55555555) c -= 1; - - return c + 1; -} |