heukelum at mailshack
Mar 15, 2008, 10:32 AM
Post #1 of 2
(86 views)
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[3/3] Use __fls for fls64 on 64-bit archs
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Use __fls for fls64 on 64-bit archs. The implementation for
64-bit archs is moved from x86_64 to asm-generic.
Signed-off-by: Alexander van Heukelum <heukelum[at]fastmail.fm>
---
include/asm-generic/bitops/fls64.h | 22 ++++++++++++++++++++++
include/asm-x86/bitops_64.h | 15 ++-------------
2 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h
index 1b6b17c..86d403f 100644
--- a/include/asm-generic/bitops/fls64.h
+++ b/include/asm-generic/bitops/fls64.h
@@ -3,6 +3,18 @@
#include <asm/types.h>
+/**
+ * fls64 - find last set bit in a 64-bit word
+ * @x: the word to search
+ *
+ * This is defined in a similar way as the libc and compiler builtin
+ * ffsll, but returns the position of the most significant set bit.
+ *
+ * fls64(value) returns 0 if value is 0 or the position of the last
+ * set bit if value is nonzero. The last (most significant) bit is
+ * at position 64.
+ */
+#if BITS_PER_LONG == 32
static inline int fls64(__u64 x)
{
__u32 h = x >> 32;
@@ -10,5 +22,15 @@ static inline int fls64(__u64 x)
return fls(h) + 32;
return fls(x);
}
+#elif BITS_PER_LONG == 64
+static inline int fls64(__u64 x)
+{
+ if (x == 0)
+ return 0;
+ return __fls(x) + 1;
+}
+#else
+#error BITS_PER_LONG not 32 or 64
+#endif
#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */
diff --git a/include/asm-x86/bitops_64.h b/include/asm-x86/bitops_64.h
index aaf1519..1f1f796 100644
--- a/include/asm-x86/bitops_64.h
+++ b/include/asm-x86/bitops_64.h
@@ -112,19 +112,6 @@ 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;
-}
-
-/**
* fls - find last bit set
* @x: the word to search
*
@@ -146,6 +133,8 @@ static inline int fls(int x)
#endif /* __KERNEL__ */
+#include <asm-generic/bitops/fls64.h>
+
#ifdef __KERNEL__
#include <asm-generic/bitops/ext2-non-atomic.h>
--
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