func (p *Package) gccMachine() []string {
	switch goarch {
	case "amd64":
		if goos == "darwin" {
			return []string{"-arch", "x86_64", "-m64"}
		}
		return []string{"-m64"}
	case "arm64":
		if goos == "darwin" {
			return []string{"-arch", "arm64"}
		}
	case "386":
		return []string{"-m32"}
	case "arm":
		return []string{"-marm"} // not thumb