X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbasic%2Fmacro.h;h=6b2aeb933fdd36bcbcc02cefea06bcc2324322ff;hp=e41aa4260fb9a6adcc05f083ea2288476cc753c0;hb=9b00a533195b7fec54a791ca02090e0799214770;hpb=0d8ff5209903cc50cb2f39c95286cd7a5d62ada1

diff --git a/src/basic/macro.h b/src/basic/macro.h
index e41aa4260..6b2aeb933 100644
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -89,6 +89,15 @@
 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
 #define UNIQ __COUNTER__
 
+/* builtins */
+#if __SIZEOF_INT__ == 4
+#define BUILTIN_FFS_U32(x) __builtin_ffs(x);
+#elif __SIZEOF_LONG__ == 4
+#define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
+#else
+#error "neither int nor long are four bytes long?!?"
+#endif
+
 /* Rounds up */
 
 #define ALIGN4(l) (((l) + 3) & ~3)