Move function for calculating number of bits into more central place.

I want to use it so more.

MFC after:	3 days

3 files changed, 14 insertions, 6 deletions

diff --git a/sbin/geom/class/raid3/geom_raid3.c b/sbin/geom/class/raid3/geom_raid3.c
index bef8424..7a8527f 100644
--- a/sbin/geom/class/raid3/geom_raid3.c
+++ b/sbin/geom/class/raid3/geom_raid3.c
@@ -155,12 +155,7 @@ raid3_label(struct gctl_req *req)
 		gctl_error(req, "Too few arguments.");
 		return;
 	}
-#ifndef BITCOUNT
-#define	BITCOUNT(x)	(((BX_(x) + (BX_(x) >> 4)) & 0x0F0F0F0F) % 255)
-#define	BX_(x)		((x) - (((x) >> 1) & 0x77777777) -		\
-			 (((x) >> 2) & 0x33333333) - (((x) >> 3) & 0x11111111))
-#endif
-	if (BITCOUNT(*nargs - 2) != 1) {
+	if (bitcount32(*nargs - 2) != 1) {
 		gctl_error(req, "Invalid number of components.");
 		return;
 	}
diff --git a/sbin/geom/misc/subr.c b/sbin/geom/misc/subr.c
index a0525af..599223a 100644
--- a/sbin/geom/misc/subr.c
+++ b/sbin/geom/misc/subr.c
@@ -95,6 +95,18 @@ g_lcm(unsigned a, unsigned b)
 	return ((a * b) / gcd(a, b));
 }
 
+uint32_t
+bitcount32(uint32_t x)
+{
+
+	x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1);
+	x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2);
+	x = (x & 0x0f0f0f0f) + ((x & 0xf0f0f0f0) >> 4);
+	x = (x & 0x00ff00ff) + ((x & 0xff00ff00) >> 8);
+	x = (x & 0x0000ffff) + ((x & 0xffff0000) >> 16);
+	return (x);
+}
+
 off_t
 g_get_mediasize(const char *name)
 {
diff --git a/sbin/geom/misc/subr.h b/sbin/geom/misc/subr.h
index ee319a9..164c3b4 100644
--- a/sbin/geom/misc/subr.h
+++ b/sbin/geom/misc/subr.h
@@ -29,6 +29,7 @@
 #ifndef _SUBR_H_
 #define	_SUBR_H_
 unsigned g_lcm(unsigned a, unsigned b);
+uint32_t bitcount32(uint32_t x);
 
 off_t g_get_mediasize(const char *name);
 unsigned g_get_sectorsize(const char *name);