swift234

[overflow] Remove signed and unsigned overflow checks for X+1 and X-1 if X is smaller/greater than some other number.
If X is known to be smaller than some other number then we can add a 1 to X.
If X is known to be grater than some other number then we can subtract 1 from X.

func add1_signed_branch(x : Int, y : Int) {
  if (x < y) {
    sink(x + 1) // remove
    sink(x + 2) // keep
  }
}

Swift SVN r26016