Merge git://oss.sgi.com:8090/xfs/xfs-2.6

[linux-drm-fsl-dcu.git] / lib / hweight.c

diff --git a/lib/hweight.c b/lib/hweight.c
index 4382576717086eeaaa48d928db67dfb6757cbbb7..360556a7803d4dae582b39edec3e91bb78ac7749 100644 (file)
--- a/lib/hweight.c
+++ b/lib/hweight.c
@@ -1,5 +1,6 @@
 #include <linux/module.h>
 #include <asm/types.h>
+#include <asm/bitops.h>
 
 /**
  * hweightN - returns the hamming weight of a N-bit word
@@ -40,14 +41,19 @@ unsigned long hweight64(__u64 w)
 #if BITS_PER_LONG == 32
        return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
 #elif BITS_PER_LONG == 64
+#ifdef ARCH_HAS_FAST_MULTIPLIER
+       w -= (w >> 1) & 0x5555555555555555ul;
+       w =  (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
+       w =  (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
+       return (w * 0x0101010101010101ul) >> 56;
+#else
        __u64 res = w - ((w >> 1) & 0x5555555555555555ul);
        res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
        res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
        res = res + (res >> 8);
        res = res + (res >> 16);
        return (res + (res >> 32)) & 0x00000000000000FFul;
-#else
-#error BITS_PER_LONG not defined
+#endif
 #endif
 }
 EXPORT_SYMBOL(hweight64);