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[PATCH] bitops: generic ffz()

This patch introduces the C-language equivalent of the function: unsigned long
ffz(unsigned long word);

In include/asm-generic/bitops/ffz.h

This code largely copied from: include/asm-parisc/bitops.h

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Akinobu Mita 19 年之前
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176d8b0c27
共有 1 個文件被更改,包括 12 次插入0 次删除
  1. 12 0
      include/asm-generic/bitops/ffz.h

+ 12 - 0
include/asm-generic/bitops/ffz.h

@@ -0,0 +1,12 @@
+#ifndef _ASM_GENERIC_BITOPS_FFZ_H_
+#define _ASM_GENERIC_BITOPS_FFZ_H_
+
+/*
+ * ffz - find first zero in word.
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+#define ffz(x)  __ffs(~(x))
+
+#endif /* _ASM_GENERIC_BITOPS_FFZ_H_ */