Moving power-of-two bit utilities into util.h

src/cache.c

@@ -9,21 +9,14 @@
 #include "repository.h"
 #include "commit.h"
 #include "thread-utils.h"
+#include "util.h"
 #include "cache.h"
 
 int git_cache_init(git_cache *cache, size_t size, git_cached_obj_freeptr free_ptr)
 {
 	if (size < 8)
 		size = 8;
-
-	/* round up size to closest power of 2 */
-	size--;
-	size |= size >> 1;
-	size |= size >> 2;
-	size |= size >> 4;
-	size |= size >> 8;
-	size |= size >> 16;
-	size++;
+	size = git__size_t_powerof2(size);
 
 	cache->size_mask = size - 1;
 	cache->lru_count = 0;

src/util.h

@@ -179,4 +179,21 @@ GIT_INLINE(int) git__ishex(const char *str)
 	return 1;
 }
 
+GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
+{
+	v--;
+	v |= v >> 1;
+	v |= v >> 2;
+	v |= v >> 4;
+	v |= v >> 8;
+	v |= v >> 16;
+
+	return v;
+}
+
+GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
+{
+	return git__size_t_bitmask(v) + 1;
+}
+
 #endif /* INCLUDE_util_h__ */