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

reuse stack slot if variable dies outgoing

Browse Source
This commit is contained in:
T0b1
2023-04-16 15:09:54 +02:00
parent d9bbbcfbe2
commit a0e2851620
1 changed files with 12 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/ion/fast_alloc.rs
View File

@@ -931,6 +931,9 @@ fn handle_out_block_params<'a, F: Function>(
in_slot, in_slot,
in_vreg in_vreg
); );
if out_slot == in_slot {
continue;
}
state.edits.push(( state.edits.push((
ProgPoint::before(last_inst), ProgPoint::before(last_inst),
Edit::Move { Edit::Move {
@@ -975,7 +978,6 @@ fn handle_out_block_params<'a, F: Function>(
state.vregs[in_vreg.vreg()].def_block = Some(succ); state.vregs[in_vreg.vreg()].def_block = Some(succ);
// TODO: if out_vreg dies at this edge, we could reuse its stack slot // TODO: if out_vreg dies at this edge, we could reuse its stack slot
// TODO: we should also be able to reuse the slot if the successor only has one predecessor (us); check with AE
let mut no_alias = false; let mut no_alias = false;
if !vregs_passed.contains(&out_vreg) { if !vregs_passed.contains(&out_vreg) {
let mut alloced = false; let mut alloced = false;
@@ -995,6 +997,14 @@ fn handle_out_block_params<'a, F: Function>(
continue; continue;
} }
vregs_passed.push(out_vreg); vregs_passed.push(out_vreg);
if !state.liveouts[block.index()].get(out_vreg.vreg()) {
// we can reuse the stack slot since the variable dies
state.vregs[in_vreg.vreg()].slot_idx =
Some(state.vregs[out_vreg.vreg()].slot_idx.unwrap());
continue;
}
no_alias = true; no_alias = true;
} }
@@ -1126,6 +1136,7 @@ impl BlockBitmap {
// currently, copy from liveranges.rs // currently, copy from liveranges.rs
// don't inline for better perf stats // don't inline for better perf stats
// this is currently very expensive, takes 3% of 10.2% total time for the register allocator
#[inline(never)] #[inline(never)]
fn calc_live_bitmaps<'a, F: Function>( fn calc_live_bitmaps<'a, F: Function>(
state: &mut FastAllocState<'a, F>, state: &mut FastAllocState<'a, F>,