chiark / gitweb /
util: add u32ctz() call for determining ctz of uint32_t
authorLennart Poettering <lennart@poettering.net>
Thu, 30 Jan 2014 15:46:48 +0000 (16:46 +0100)
committerLennart Poettering <lennart@poettering.net>
Thu, 30 Jan 2014 15:47:18 +0000 (16:47 +0100)
src/shared/util.h

index 117855d..e4de472 100644 (file)
@@ -743,7 +743,19 @@ static inline void _reset_umask_(struct _umask_struct_ *s) {
              _saved_umask_.quit = true)
 
 static inline unsigned u64log2(uint64_t n) {
+#if __SIZEOF_LONG_LONG__ == 8
         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
+#else
+#error "Wut?"
+#endif
+}
+
+static inline unsigned u32ctz(uint32_t n) {
+#if __SIZEOF_INT__ == 4
+        return __builtin_ctz(n);
+#else
+#error "Wut?"
+#endif
 }
 
 static inline bool logind_running(void) {