diff options
Diffstat (limited to 'lib/misc/util.h')
| -rw-r--r-- | lib/misc/util.h | 107 |
1 files changed, 106 insertions, 1 deletions
diff --git a/lib/misc/util.h b/lib/misc/util.h index a453469..35514ee 100644 --- a/lib/misc/util.h +++ b/lib/misc/util.h @@ -9,12 +9,14 @@ * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, - * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef _LVM_UTIL_H #define _LVM_UTIL_H +#include <inttypes.h> + #define min(a, b) ({ typeof(a) _a = (a); \ typeof(b) _b = (b); \ (void) (&_a == &_b); \ @@ -25,12 +27,115 @@ (void) (&_a == &_b); \ _a > _b ? _a : _b; }) +#define is_power_of_2(n) ((n) && !((n) & ((n) - 1))) + #if defined(__clang__) || (defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 6) #define uninitialized_var(x) x #else #define uninitialized_var(x) x = x #endif +/* + * GCC 3.4 adds a __builtin_clz, which uses the count leading zeros (clz) + * instruction on arches that have one. Provide a fallback using shifts + * and comparisons for older compilers. + */ +#ifdef HAVE___BUILTIN_CLZ +#define clz(x) __builtin_clz((x)) +#else /* ifdef HAVE___BUILTIN_CLZ */ +static unsigned _dm_clz(unsigned x) +{ + int n; + + if ((int)x <= 0) return (~x >> 26) & 32; + + n = 1; + + if ((x >> 16) == 0) { + n = n + 16; + x = x << 16; + } + + if ((x >> 24) == 0) { + n = n + 8; + x = x << 8; + } + + if ((x >> 28) == 0) { + n = n + 4; + x = x << 4; + } + + if ((x >> 30) == 0) { + n = n + 2; + x = x << 2; + } + n = n - (x >> 31); + return n; +} +#define clz(x) _dm_clz((x)) +#endif /* ifdef HAVE___BUILTIN_CLZ */ + +#ifdef HAVE___BUILTIN_CLZLL +#define clzll(x) __builtin_clzll((x)) +#else /* ifdef HAVE___BUILTIN_CLZ */ +static unsigned _dm_clzll(unsigned long long x) +{ + if (x <= 0xffffffff) + return 32 + clz((unsigned) (x & 0xffffffff)); + + return clz(x >> 32); +} +#define clzll(x) _dm_clzll((x)) +#endif /* ifdef HAVE___BUILTIN_CLZLL */ + +#ifndef HAVE_FFS +#ifdef HAVE___BUILTIN_FFS +#define ffs(x) __builtin_ffs((x)) +#else +#error ffs() not implemented! +#endif /* ifdef HAVE___BUILTIN_FFS */ +#endif /* ifndef HAVE_FFS */ + #define KERNEL_VERSION(major, minor, release) (((major) << 16) + ((minor) << 8) + (release)) +/* Define some portable printing types */ +#define PRIsize_t "zu" +#define PRIssize_t "zd" +#define PRIptrdiff_t "td" +#define PRIpid_t PRId32 + +/* For convenience */ +#define FMTsize_t "%" PRIsize_t +#define FMTssize_t "%" PRIssize_t +#define FMTptrdiff_t "%" PRIptrdiff_t +#define FMTpid_t "%" PRIpid_t + +#define FMTd8 "%" PRId8 +#define FMTd16 "%" PRId16 +#define FMTd32 "%" PRId32 +#define FMTd64 "%" PRId64 + +#define FMTi8 "%" PRIi8 +#define FMTi16 "%" PRIi16 +#define FMTi32 "%" PRIi32 +#define FMTi64 "%" PRIi64 + +#define FMTo8 "%" PRIo8 +#define FMTo16 "%" PRIo16 +#define FMTo32 "%" PRIo32 +#define FMTo64 "%" PRIo64 + +#define FMTu8 "%" PRIu8 +#define FMTu16 "%" PRIu16 +#define FMTu32 "%" PRIu32 +#define FMTu64 "%" PRIu64 + +#define FMTx8 "%" PRIx8 +#define FMTx16 "%" PRIx16 +#define FMTx32 "%" PRIx32 +#define FMTx64 "%" PRIx64 + +#define FMTVGID "%." DM_TO_STRING(ID_LEN) "s" + #endif |