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-rw-r--r--include/asm-x86_64/bitops.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/include/asm-x86_64/bitops.h b/include/asm-x86_64/bitops.h
index 05a0d374404b..a4d5d0909453 100644
--- a/include/asm-x86_64/bitops.h
+++ b/include/asm-x86_64/bitops.h
@@ -340,6 +340,20 @@ static __inline__ unsigned long __ffs(unsigned long word)
return word;
}
+/*
+ * __fls: find last bit set.
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+static __inline__ unsigned long __fls(unsigned long word)
+{
+ __asm__("bsrq %1,%0"
+ :"=r" (word)
+ :"rm" (word));
+ return word;
+}
+
#ifdef __KERNEL__
static inline int sched_find_first_bit(const unsigned long *b)
@@ -370,6 +384,19 @@ static __inline__ int ffs(int x)
}
/**
+ * fls64 - find last bit set in 64 bit word
+ * @x: the word to search
+ *
+ * This is defined the same way as fls.
+ */
+static __inline__ int fls64(__u64 x)
+{
+ if (x == 0)
+ return 0;
+ return __fls(x) + 1;
+}
+
+/**
* hweightN - returns the hamming weight of a N-bit word
* @x: the word to weigh
*