From b15cbc0be004d352d4dd661546847bd52fbf8a28 Mon Sep 17 00:00:00 2001
From: wdenk <wdenk>
Date: Mon, 21 Aug 2000 15:05:47 +0000
Subject: Initial revision

---
 include/linux/bitops.h | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 include/linux/bitops.h

(limited to 'include/linux/bitops.h')

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
new file mode 100644
index 0000000..b155b77
--- /dev/null
+++ b/include/linux/bitops.h
@@ -0,0 +1,72 @@
+#ifndef _LINUX_BITOPS_H
+#define _LINUX_BITOPS_H
+
+
+/*
+ * 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).
+ */
+
+static inline int generic_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;
+}
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+
+static inline unsigned int generic_hweight32(unsigned int w)
+{
+        unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
+        res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+        res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
+        res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
+        return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
+}
+
+static inline unsigned int generic_hweight16(unsigned int w)
+{
+        unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
+        res = (res & 0x3333) + ((res >> 2) & 0x3333);
+        res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
+        return (res & 0x00FF) + ((res >> 8) & 0x00FF);
+}
+
+static inline unsigned int generic_hweight8(unsigned int w)
+{
+        unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
+        res = (res & 0x33) + ((res >> 2) & 0x33);
+        return (res & 0x0F) + ((res >> 4) & 0x0F);
+}
+
+#include <asm/bitops.h>
+
+
+#endif
-- 
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