summaryrefslogtreecommitdiff
path: root/libdde_linux26/contrib/include/asm-generic/bitops/ffs.h
diff options
context:
space:
mode:
authorZheng Da <zhengda1936@gmail.com>2009-12-06 05:26:23 +0100
committerZheng Da <zhengda1936@gmail.com>2009-12-06 05:26:23 +0100
commit8a6d48c0542876eb3acfc0970c0ab7872db08d5f (patch)
tree496e78bc728317ea779781b92f897d16936ee231 /libdde_linux26/contrib/include/asm-generic/bitops/ffs.h
parentb4bffcfcdf3ab7a55d664e9aa5907f88da503f38 (diff)
check in the original version of dde linux26.
Diffstat (limited to 'libdde_linux26/contrib/include/asm-generic/bitops/ffs.h')
-rw-r--r--libdde_linux26/contrib/include/asm-generic/bitops/ffs.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/asm-generic/bitops/ffs.h b/libdde_linux26/contrib/include/asm-generic/bitops/ffs.h
new file mode 100644
index 00000000..fbbb43af
--- /dev/null
+++ b/libdde_linux26/contrib/include/asm-generic/bitops/ffs.h
@@ -0,0 +1,41 @@
+#ifndef _ASM_GENERIC_BITOPS_FFS_H_
+#define _ASM_GENERIC_BITOPS_FFS_H_
+
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+static inline int ffs(int x)
+{
+ int r = 1;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */