New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add facility for hiding values from the compiler #74

Open

dabrahams opened this issue Aug 28, 2020 · 0 comments

Contributor

dabrahams commented Aug 28, 2020

/// Returns `x`, preventing its value from being statically known by the optimizer.
@inline(__always)
fileprivate func hideValue<T>(_ x: T) -> T {
  
  @_optimize(none) 
  func assumePointeeIsWritten<T>(_ x: UnsafeMutablePointer<T>) {}
  
  var copy = x
  withUnsafeMutablePointer(to: &copy) { assumePointeeIsWritten($0) }
  return copy
}

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment