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authorSage Weil <sage@inktank.com>2013-08-15 11:11:45 -0700
committerSage Weil <sage@inktank.com>2013-08-15 11:11:45 -0700
commitee3e542fec6e69bc9fb668698889a37d93950ddf (patch)
treee74ee766a4764769ef1d3d45d266b4dea64101d3 /lib/clz_ctz.c
parentfe2a801b50c0bb8039d627e5ae1fec249d10ff39 (diff)
parentf1d6e17f540af37bb1891480143669ba7636c4cf (diff)
Merge remote-tracking branch 'linus/master' into testing
Diffstat (limited to 'lib/clz_ctz.c')
-rw-r--r--lib/clz_ctz.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/clz_ctz.c b/lib/clz_ctz.c
new file mode 100644
index 00000000000..a8f8379eb49
--- /dev/null
+++ b/lib/clz_ctz.c
@@ -0,0 +1,58 @@
+/*
+ * lib/clz_ctz.c
+ *
+ * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+int __weak __ctzsi2(int val)
+{
+ return __ffs(val);
+}
+EXPORT_SYMBOL(__ctzsi2);
+
+int __weak __clzsi2(int val)
+{
+ return 32 - fls(val);
+}
+EXPORT_SYMBOL(__clzsi2);
+
+#if BITS_PER_LONG == 32
+
+int __weak __clzdi2(long val)
+{
+ return 32 - fls((int)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+
+int __weak __ctzdi2(long val)
+{
+ return __ffs((u32)val);
+}
+EXPORT_SYMBOL(__ctzdi2);
+
+#elif BITS_PER_LONG == 64
+
+int __weak __clzdi2(long val)
+{
+ return 64 - fls64((u64)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+
+int __weak __ctzdi2(long val)
+{
+ return __ffs64((u64)val);
+}
+EXPORT_SYMBOL(__ctzdi2);
+
+#else
+#error BITS_PER_LONG not 32 or 64
+#endif