diff options
| -rw-r--r-- | configure.ac | 1 | ||||
| -rw-r--r-- | src/utils.h | 13 |
2 files changed, 14 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 3f8de97..da201e1 100644 --- a/configure.ac +++ b/configure.ac @@ -83,6 +83,7 @@ AS_IF([test "x$ac_cv_func_secure_getenv" = xno -a \ ]) AX_GCC_BUILTIN(__builtin_expect) +AX_GCC_BUILTIN(__builtin_popcount) # Some tests use Linux-specific headers AC_CHECK_HEADER([linux/input.h]) diff --git a/src/utils.h b/src/utils.h index 4b7e81c..11ef735 100644 --- a/src/utils.h +++ b/src/utils.h @@ -178,6 +178,19 @@ msb_pos(uint32_t mask) return pos; } +static inline int +popcount(uint32_t x) +{ + int count; +#if defined(HAVE___BUILTIN_POPCOUNT) + count = __builtin_popcount(x); +#else + for (count = 0; x; count++) + x &= x - 1; +#endif + return count; +} + bool map_file(FILE *file, char **string_out, size_t *size_out); |