T0b1/regalloc2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Remove unused pred_pos

Browse Source
This commit is contained in:
Chris Fallin
2021-06-19 11:48:54 -07:00
parent 36975b8b6f
commit caf7274efd
1 changed files with 1 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
src/cfg.rs
View File

@@ -26,15 +26,6 @@ pub struct CFGInfo {
pub block_entry: Vec<ProgPoint>,
/// For each block, the last instruction.
pub block_exit: Vec<ProgPoint>,
/// For each block, what is its position in its successor's preds,
/// if it has a single successor?
///
/// (Because we require split critical edges, we always either have a single
/// successor (which itself may have multiple preds), or we have multiple
/// successors but each successor itself has only one pred; so we can store
/// just one value per block and always know any block's position in its
/// successors' preds lists.)
pub pred_pos: Vec<usize>,
/// For each block, what is the approximate loop depth?
///
/// This measure is fully precise iff the input CFG is reducible
@@ -60,7 +51,6 @@ impl CFGInfo {
let mut vreg_def_blockparam = vec![(Block::invalid(), 0); f.num_vregs()];
let mut block_entry = vec![ProgPoint::before(Inst::invalid()); f.blocks()];
let mut block_exit = vec![ProgPoint::before(Inst::invalid()); f.blocks()];
let mut pred_pos = vec![0; f.blocks()];
let mut backedge_in = vec![0; f.blocks()];
let mut backedge_out = vec![0; f.blocks()];
@@ -88,12 +78,11 @@ impl CFGInfo {
// (this block).
let preds = f.block_preds(block).len() + if block == f.entry_block() { 1 } else { 0 };
if preds > 1 {
for (i, &pred) in f.block_preds(block).iter().enumerate() {
for &pred in f.block_preds(block) {
let succs = f.block_succs(pred).len();
if succs > 1 {
return Err(RegAllocError::CritEdge(pred, block));
}
pred_pos[pred.index()] = i;
}
}
@@ -153,7 +142,6 @@ impl CFGInfo {
vreg_def_blockparam,
block_entry,
block_exit,
pred_pos,
approx_loop_depth,
})
}
@@ -161,14 +149,4 @@ impl CFGInfo {
pub fn dominates(&self, a: Block, b: Block) -> bool {
domtree::dominates(&self.domtree[..], a, b)
}
/// Return the position of this block in its successor's predecessor list.
///
/// Because the CFG must have split critical edges, we actually do not need
/// to know *which* successor: if there is more than one, then each
/// successor has only one predecessor (that's this block), so the answer is
/// `0` no matter which successor we are considering.
pub fn pred_position(&self, block: Block) -> usize {
self.pred_pos[block.index()]
}
}