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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/ffs.h
parent38c2c2458e3f4ecb329ff35621806252aac209b9 (diff)
parent8df772b3c665e663f6f9d2a70f9c691590bd3f91 (diff)
Merge branch 'dde' into upstream-merged
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_ */