X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=lib%2Fhweight.c;h=360556a7803d4dae582b39edec3e91bb78ac7749;hb=cb18eccff48ef3986d1072964590bce6fec705fb;hp=721a4b8b4fb8420b742e86cf84c08e030c946a8c;hpb=3b9ed1a5d2d121f32d2cb4f2b05f1fc57c99c946;p=powerpc.git

diff --git a/lib/hweight.c b/lib/hweight.c
index 721a4b8b4f..360556a780 100644
--- 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
@@ -10,28 +11,28 @@
 
 unsigned int hweight32(unsigned int w)
 {
-	unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
+	unsigned int res = w - ((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);
+	res = (res + (res >> 4)) & 0x0F0F0F0F;
+	res = res + (res >> 8);
+	return (res + (res >> 16)) & 0x000000FF;
 }
 EXPORT_SYMBOL(hweight32);
 
 unsigned int hweight16(unsigned int w)
 {
-	unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
+	unsigned int res = w - ((w >> 1) & 0x5555);
 	res = (res & 0x3333) + ((res >> 2) & 0x3333);
-	res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
-	return (res & 0x00FF) + ((res >> 8) & 0x00FF);
+	res = (res + (res >> 4)) & 0x0F0F;
+	return (res + (res >> 8)) & 0x00FF;
 }
 EXPORT_SYMBOL(hweight16);
 
 unsigned int hweight8(unsigned int w)
 {
-	unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
+	unsigned int res = w - ((w >> 1) & 0x55);
 	res = (res & 0x33) + ((res >> 2) & 0x33);
-	return (res & 0x0F) + ((res >> 4) & 0x0F);
+	return (res + (res >> 4)) & 0x0F;
 }
 EXPORT_SYMBOL(hweight8);
 
@@ -40,15 +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
-	u64 res;
-	res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul);
-	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
-	res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful);
-	res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul);
-	res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul);
-	return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul);
+#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
-#error BITS_PER_LONG not defined
+	__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;
+#endif
 #endif
 }
 EXPORT_SYMBOL(hweight64);