Add parity() helper

21f905e1 · Rémi Denis-Courmont · 6eec2a06 · 21f905e1
Commit 21f905e1 authored Mar 18, 2012 by Rémi Denis-Courmont
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include/vlc_common.h include/vlc_common.h +12 -0

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--- 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