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authorDmitry Torokhov <dtor_core@ameritech.net>2006-04-02 09:08:05 +0400
committerDmitry Torokhov <dtor_core@ameritech.net>2006-04-02 09:08:05 +0400
commit95d465fd750897ab32462a6702fbfe1b122cbbc0 (patch)
tree65c38b2f11c51bb6932e44dd6c92f15b0091abfe /include/asm-generic/bitops/ffs.h
parent642fde17dceceb56c7ba2762733ac688666ae657 (diff)
parent683aa4012f53b2ada0f430487e05d37b0d94e90a (diff)
downloadlinux-95d465fd750897ab32462a6702fbfe1b122cbbc0.tar.xz
Manual merge with Linus.
Conflicts: arch/powerpc/kernel/setup-common.c drivers/input/keyboard/hil_kbd.c drivers/input/mouse/hil_ptr.c
Diffstat (limited to 'include/asm-generic/bitops/ffs.h')
-rw-r--r--include/asm-generic/bitops/ffs.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/ffs.h b/include/asm-generic/bitops/ffs.h
new file mode 100644
index 000000000000..fbbb43af7dc0
--- /dev/null
+++ b/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_ */