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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:14:24 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:14:24 +0000
commit6fafeb146e9efd59140ea58cebd7dd38ae9a6379 (patch)
tree7db89ba6a28932514b105d620bba4884ec332ec3 /libdde_linux26/contrib/include/asm-generic/bitops/fls64.h
parent38c2c2458e3f4ecb329ff35621806252aac209b9 (diff)
parent8df772b3c665e663f6f9d2a70f9c691590bd3f91 (diff)
Merge branch 'dde' into upstream-merged
Diffstat (limited to 'libdde_linux26/contrib/include/asm-generic/bitops/fls64.h')
-rw-r--r--libdde_linux26/contrib/include/asm-generic/bitops/fls64.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h b/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h
new file mode 100644
index 00000000..b097cf84
--- /dev/null
+++ b/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h
@@ -0,0 +1,36 @@
+#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
+#define _ASM_GENERIC_BITOPS_FLS64_H_
+
+#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 __always_inline int fls64(__u64 x)
+{
+ __u32 h = x >> 32;
+ if (h)
+ return fls(h) + 32;
+ return fls(x);
+}
+#elif BITS_PER_LONG == 64
+static __always_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_ */