title: What predefined macro can I use to detect the target architecture in Clang?
body: <p>I would like to write code depending on whether the target architecture is e.g. armv7, armv7s, or arm64.</p>
  
  <p>The reason that I can't use <a href="https://stackoverflow.com/questions/19859388/how-can-i-get-the-ios-device-cpu-architecture-in-runtime">sysctlbyname</a> is that this would give me the underlying architecture at runtime, but when arm64 e.g. simulates armv7, sysctl (seemingly) still reports arm64.</p>