Require: An execution trace .
Ensure: The execution trace in SSA form and a function that maps each variable
    to its maximum index value used in the SSA form.
(1) Let index be a function mapping variables to integers. The initial integer value
  for each variable is 0.
(2) Let be the empty sequence.
(3) for   to   do
(4)   If    is an assignment statement of the form   then
(5)     Let be where all variables are replaced with .
(6)     Let be .
(7)     Add to the end of the sequence .
(8)   else
(9)     Let be the statement where all variables are replaced with
       .
(10)    Add to the end of the sequence .
(11)  end if
(12) end for
(13) Return .
Algorithm 2: SSA( ).