case "RotateLeft", "Reverse", "ReverseBytes":
				fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", %d)\n", size, e.in)
				if e.name == "RotateLeft" {
					fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d, 2))\n", size, f, e.in)
					fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d, -2))\n", size, f, e.in)
				} else {
					fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d))\n", size, f, e.in)
				}

	// the main part of the program can be run.
	fmt.Fprintf(&w, "\tif os.Getenv(\"LINKTESTARG\") != \"\" {\n")
	for i := 0; i < FN; i++ {
		fmt.Fprintf(&w, "\t\tbigfn%d()\n", i)
	}
	fmt.Fprintf(&w, "\t}\n")
	fmt.Fprintf(&w, "\tfmt.Printf(\"PASS\\n\")\n")
	fmt.Fprintf(&w, "}")
	err := os.WriteFile(tmpdir+"/bigfn.go", w.Bytes(), 0666)
	if err != nil {
		t.Fatalf("can't write output: %v\n", err)
	}

	// Build and run with internal linking.