let prologue () =
let sep_of = Value_parameters.SeparateStmtOf.get() in
if sep_of <> 0
then begin
let sep_case = Value_parameters.SeparateStmtWord.get() in
Value_parameters.feedback "Part of a case analysis: %d of 0..%d"
sep_case
sep_of;
assert (sep_of >= 1);
assert (sep_of <= 1073741823); (* should be enough for anyone *)
assert (sep_of land (succ sep_of) = 0); (* pred of power of two *)
assert (sep_case >= 0);
assert (sep_case <= sep_of);
mask := (succ sep_of) lsr 1;
end
else begin
mask := 0;
end