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add pass_add_sub_offset

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nora 2022-04-16 12:35:26 +02:00
parent 4490d49d35
commit 014770b6fe
4 changed files with 51 additions and 15 deletions
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42
rust2/src/opts.rs
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@ -42,6 +42,8 @@ impl Debug for Stmt<'_> {
pub enum StmtKind<'ir> {
Add(u8),
Sub(u8),
AddOffset(i32, u8),
SubOffset(i32, u8),
Right(usize),
Left(usize),
Loop(Ir<'ir>),
@ -211,9 +213,27 @@ fn pass_cancel_left_right_add_sub(ir: &mut Ir<'_>) {
})
}
/// pass that replaces `Right(9) Add(5) Left(9)` with `AddOffset(9)`
/// pass that replaces `Right(9) Add(5) Left(9)` with `AddOffset(9, 5)`
#[tracing::instrument]
fn pass_add_sub_offset(ir: &mut Ir<'_>) {}
fn pass_add_sub_offset(ir: &mut Ir<'_>) {
window_pass(ir, pass_add_sub_offset, |[a, b, c]| {
match (a.kind(), b.kind(), c.kind()) {
(StmtKind::Right(r), StmtKind::Add(n), StmtKind::Left(l)) if r == l => {
WindowPassAction::Merge(StmtKind::AddOffset(i32::try_from(*r).unwrap(), *n))
}
(StmtKind::Left(l), StmtKind::Add(n), StmtKind::Right(r)) if r == l => {
WindowPassAction::Merge(StmtKind::AddOffset(-i32::try_from(*r).unwrap(), *n))
}
(StmtKind::Right(r), StmtKind::Sub(n), StmtKind::Left(l)) if r == l => {
WindowPassAction::Merge(StmtKind::SubOffset(i32::try_from(*r).unwrap(), *n))
}
(StmtKind::Left(l), StmtKind::Sub(n), StmtKind::Right(r)) if r == l => {
WindowPassAction::Merge(StmtKind::SubOffset(-i32::try_from(*r).unwrap(), *n))
}
_ => WindowPassAction::None,
}
})
}
enum WindowPassAction<'ir> {
None,
@ -236,13 +256,10 @@ where
pass_recur(body);
}
if i >= stmts.len() - (N - 1) {
if i + N > stmts.len() {
break; // there aren't N elements left
}
let a = &stmts[i];
let b = &stmts[i + 1];
let mut elements = stmts[i..][..N].iter();
let elements = [(); N].map(|()| elements.next().unwrap());
@ -255,13 +272,16 @@ where
i += 1;
}
WindowPassAction::RemoveAll => {
trace!(?a, ?b, "Removing both statements");
stmts.remove(i);
stmts.remove(i);
trace!(?elements, "Removing all statements");
for _ in 0..N {
stmts.remove(i);
}
}
WindowPassAction::Merge(new) => {
trace!(?a, ?b, ?new, "Merging statements");
stmts.remove(i + 1);
trace!(?elements, ?new, "Merging statements");
for _ in 1..N {
stmts.remove(i);
}
stmts[i] = Stmt::new(new, merged_span);
}
}