diff --git a/container/intsets/util.go b/container/intsets/util.go
index dd1db86b..67102781 100644
--- a/container/intsets/util.go
+++ b/container/intsets/util.go
@@ -4,16 +4,6 @@
 
 package intsets
 
-// From Hacker's Delight, fig 5.2.
-func popcountHD(x uint32) int {
-	x -= (x >> 1) & 0x55555555
-	x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
-	x = (x + (x >> 4)) & 0x0f0f0f0f
-	x = x + (x >> 8)
-	x = x + (x >> 16)
-	return int(x & 0x0000003f)
-}
-
 var a [1 << 8]byte
 
 func init() {