[vlc-commits] Add parity() helper

[Rémi Denis-Courmont]

vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Mar 18 11:36:55 2012 +0200| [21f905e175e5851c3c52a01697c7c795460e5067] | committer: Rémi Denis-Courmont

Add parity() helper

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=21f905e175e5851c3c52a01697c7c795460e5067
---

 include/vlc_common.h |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/include/vlc_common.h b/include/vlc_common.h
index 5cb0adf..92c36c4 100644
--- a/include/vlc_common.h
+++ b/include/vlc_common.h
@@ -616,6 +616,18 @@ static inline unsigned popcount (unsigned x)
 #endif
 }
 
+VLC_USED
+static inline unsigned parity (unsigned x)
+{
+#if VLC_GCC_VERSION(3,4)
+    return __builtin_parity (x);
+#else
+    for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
+        x ^= x >> i;
+    return x & 1;
+#endif
+}
+
 #ifdef __OS2__
 #   undef bswap16
 #   undef bswap32