Check if the current CPU has AVX2 support

detect_axv2_always.go

@@ -0,0 +1,7 @@
+//go:build amd64.v3
+
+package and
+
+func hasAVX2() bool {
+	return true
+}

detect_axv2_never.go

@@ -0,0 +1,7 @@
+//go:build !amd64
+
+package and
+
+func hasAVX2() bool {
+	return false
+}

detect_axv2_runtime.go

@@ -0,0 +1,9 @@
+//go:build amd64 && !amd64.v3
+
+package and
+
+import "golang.org/x/sys/cpu"
+
+func hasAVX2() bool {
+	return cpu.X86.HasAVX2
+}

go.mod

@@ -1,3 +1,5 @@
 module github.com/bwesterb/go-and
 
 go 1.22.0
+
+require golang.org/x/sys v0.22.0

go.sum

@@ -0,0 +1,2 @@
+golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
+golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

lib.go

@@ -13,7 +13,11 @@ func And(dst, a, b []byte) {
 		panic("lengths of a, b and dst must be equal")
 	}
 
-	and(dst, a, b)
+	if hasAVX2() {
+		and(dst, a, b)
+		return
+	}
+	andGeneric(dst, a, b)
 }
 
 func andGeneric(dst, a, b []byte) {