X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fhweight.c;h=2c819d6a41a85f4965123aa7c7b109dbcce36ce9;hb=fde57152fc4d04099588c83cdb8beb433b6ad7bd;hp=738ed277380118eca1672e7095023c95ac7340c6;hpb=51aa2da8cf422a06ddfa1ce673f3bfc03f96b86e;p=fio.git

diff --git a/lib/hweight.c b/lib/hweight.c
index 738ed277..2c819d6a 100644
--- a/lib/hweight.c
+++ b/lib/hweight.c
@@ -17,3 +17,17 @@ unsigned int hweight32(uint32_t w)
 	res = res + (res >> 8);
 	return (res + (res >> 16)) & 0x000000FF;
 }
+
+unsigned int hweight64(uint64_t w)
+{
+#if BITS_PER_LONG == 32
+	return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
+#else
+	uint64_t res = w - ((w >> 1) & 0x5555555555555555ULL);
+	res = (res & 0x3333333333333333ULL) + ((res >> 2) & 0x3333333333333333ULL);
+	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
+	res = res + (res >> 8);
+	res = res + (res >> 16);
+	return (res + (res >> 32)) & 0x00000000000000FFULL;
+#endif
+}