X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_eal%2Fcommon%2Finclude%2Frte_common.h;h=7b50b84795b0dc43e64a78ecc5cf15d61f43979e;hb=43c9e6c205ab491779c67bba5be3ff8c3f45998e;hp=d102f2cecb21f18ef6c0ca7aa58cb86726033287;hpb=4e261f551986d40fa0c8388ed50899b609add04b;p=dpdk.git

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index d102f2cecb..7b50b84795 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -547,6 +547,24 @@ rte_bsf64_safe(uint64_t v, uint32_t *pos)
 	return 1;
 }
 
+/**
+ * Return the last (most-significant) bit set.
+ *
+ * @note The last (most significant) bit is at position 64.
+ * @note rte_fls_u64(0) = 0, rte_fls_u64(1) = 1,
+ *       rte_fls_u64(0x8000000000000000) = 64
+ *
+ * @param x
+ *     The input parameter.
+ * @return
+ *     The last (most-significant) bit set, or 0 if the input is 0.
+ */
+static inline int
+rte_fls_u64(uint64_t x)
+{
+	return (x == 0) ? 0 : 64 - __builtin_clzll(x);
+}
+
 #ifndef offsetof
 /** Return the offset of a field in a structure. */
 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)