#ifndef UTIL_H
#define UTIL_H 1
+#include <limits.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
char *follow_symlinks(const char *filename);
void ignore(bool x OVS_UNUSED);
+
+/* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0.
+ *
+ * This compiles to a single machine instruction ("bsf") with GCC on x86. */
+#if !defined(UINT_MAX) || !defined(UINT32_MAX)
+#error "Someone screwed up the #includes."
+#elif __GNUC__ >= 4 && UINT_MAX == UINT32_MAX
+static inline int
+raw_ctz(uint32_t n)
+{
+ return __builtin_ctz(n);
+}
+#else
+/* Defined in util.c. */
+int raw_ctz(uint32_t n);
+#endif
+
+/* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
+static inline int
+ctz(uint32_t n)
+{
+ return n ? raw_ctz(n) : 32;
+}
+
int log_2_floor(uint32_t);
int log_2_ceil(uint32_t);
-int ctz(uint32_t);
+int popcount(uint32_t);
bool is_all_zeros(const uint8_t *, size_t);
bool is_all_ones(const uint8_t *, size_t);