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authorStefan Roese <sr@denx.de>2007-08-21 16:33:33 +0200
committerStefan Roese <sr@denx.de>2007-08-21 16:33:33 +0200
commit93f798346033a1f6d22090b47abad4be88243b04 (patch)
tree45b4d2a887a89572015de3234b04b419bfc11b44 /include/asm-m68k/bitops.h
parent3ad63878737a5a2b1e60825bf0a7d601d7a695e7 (diff)
parent3e66c078003607a7d1d214c15a5f262bc1b4032f (diff)
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Merge with /home/stefan/git/u-boot/u-boot-ppc4xx
Diffstat (limited to 'include/asm-m68k/bitops.h')
-rw-r--r--include/asm-m68k/bitops.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/include/asm-m68k/bitops.h b/include/asm-m68k/bitops.h
index 3283714..0f9e8ab 100644
--- a/include/asm-m68k/bitops.h
+++ b/include/asm-m68k/bitops.h
@@ -15,4 +15,43 @@ extern int test_and_set_bit(int nr, volatile void *addr);
extern int test_and_clear_bit(int nr, volatile void *addr);
extern int test_and_change_bit(int nr, volatile void *addr);
+#ifdef __KERNEL__
+
+/*
+ * ffs: find first bit set. This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+extern __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;
+}
+#define __ffs(x) (ffs(x) - 1)
+
+#endif /* __KERNEL__ */
+
#endif /* _M68K_BITOPS_H */