X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=src%2Flibpspp%2Fsparse-array.c;h=6471bbacf44a83ad919477c35d5c7b6b2ed1a37d;hb=ccead09ac2bc67bbaa40e67904f6c48f7cdf6700;hp=7af219bcb080cd0a75b8b6bf9f823d2f397618a1;hpb=c4b4f06dbfcff9582548a72d4e9ca0ffc90077fc;p=pspp-builds.git

diff --git a/src/libpspp/sparse-array.c b/src/libpspp/sparse-array.c
index 7af219bc..6471bbac 100644
--- a/src/libpspp/sparse-array.c
+++ b/src/libpspp/sparse-array.c
@@ -447,6 +447,9 @@ unset_in_use (struct leaf_node *leaf, unsigned int key)
 static inline int
 count_trailing_zeros (unsigned long int x)
 {
+#if __GNUC__ >= 4
+  return __builtin_ctzl (x);
+#else /* not GCC 4+ */
   /* This algorithm is from _Hacker's Delight_ section 5.4. */
   int n = 1;
 
@@ -469,6 +472,7 @@ count_trailing_zeros (unsigned long int x)
   COUNT_STEP (2);
 
   return n - (x & 1);
+#endif /* not GCC 4+ */
 }
 
 /* Returns the least index of the in-use element in LEAF greater