4 ms·

It's easier for compilers to optimize. https://en.wikipedia.org/wiki/Static_single_assignment_form https://en.wikipedia.org/wiki/Static_single_assignment_form

• nn3 7y ago
  It actually is not. The compiler has no problems turning your imperative code into SSA on its own, and PHI functions are no problem for optimizers. I guess it's just for readability and easier reasoning about the code.
  • guerrilla 7y ago
    Your claim is that not having to do something is not easier than doing it? Ok.
    • vardump 7y ago
      The point is that there's absolutely no difference for a compiler that uses SSA form. So it's not like it has to do something extra.
• ternaryoperator 7y ago
  You're not the OP of the comment, who is a compiler writer (C, C++, D). I hope he'll weigh in with his rationale.
• masklinn 7y ago
  Any MFA code is trivially converted to SSA and that's pretty much the first thing your compiler will do. So doing SSA by hand makes no real difference to the compiler unless your compiler is so trivial it doesn't start by converting its input to SSA.