func doinit() {
	options = []option{
		{Name: "adx", Feature: &X86.HasADX},
		{Name: "aes", Feature: &X86.HasAES},
		{Name: "erms", Feature: &X86.HasERMS},
		{Name: "pclmulqdq", Feature: &X86.HasPCLMULQDQ},
		{Name: "rdtscp", Feature: &X86.HasRDTSCP},
		{Name: "sha", Feature: &X86.HasSHA},
	}
	level := getGOAMD64level()
	if level < 2 {
		// These options are required at level 2. At lower levels
		// they can be turned off.