diff options
| author | Angel Pons <th3fanbus@gmail.com> | 2020-10-14 17:48:05 +0200 |
|---|---|---|
| committer | Angel Pons <th3fanbus@gmail.com> | 2020-10-15 19:01:51 +0000 |
| commit | e0ce60c744f0ebea16bd6a1665f23ccf4461c7c3 (patch) | |
| tree | a7e47047d16236c189ab0c8ad822db2d187c8fe4 /src/include | |
| parent | e1db55b43ea2e450a215efad1228498493dd6086 (diff) | |
lib and libpayload: Add popcnt functions
Add 32-bit `popcnt` and 64-bit `popcnt64` helpers.
Change-Id: I2e6a1007e475b662a85c067d96f81326e7f02905
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46421
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/lib.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/include/lib.h b/src/include/lib.h index a0003d3e29..5c6eef2a70 100644 --- a/src/include/lib.h +++ b/src/include/lib.h @@ -46,6 +46,8 @@ void hexdump32(char LEVEL, const void *d, size_t len); */ size_t hexstrtobin(const char *str, uint8_t *buf, size_t len); +/* Population Count: number of bits that are one */ +static inline int popcnt(u32 x) { return __builtin_popcount(x); } /* Count Leading Zeroes: clz(0) == 32, clz(0xf) == 28, clz(1 << 31) == 0 */ static inline int clz(u32 x) { return x ? __builtin_clz(x) : sizeof(x) * 8; } /* Integer binary logarithm (rounding down): log2(0) == -1, log2(5) == 2 */ @@ -56,6 +58,7 @@ static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); } /* Integer binary logarithm (rounding up): log2_ceil(0) == -1, log2(5) == 3 */ static inline int log2_ceil(u32 x) { return (x == 0) ? -1 : log2(x * 2 - 1); } +static inline int popcnt64(u64 x) { return __builtin_popcountll(x); } static inline int clz64(u64 x) { return x ? __builtin_clzll(x) : sizeof(x) * 8; } static inline int log2_64(u64 x) { return sizeof(x) * 8 - clz64(x) - 1; } static inline int __ffs64(u64 x) { return log2_64(x & (u64)(-(s64)x)); } |