fix to prog-move handling: happens in middle of inst; and insert uses to make later move-insertion happy with this

This commit is contained in:
Chris Fallin
2021-05-09 03:51:10 -07:00
parent 8d7530d3fa
commit 34421fcc6b

View File

@@ -1311,7 +1311,7 @@ impl<'a, F: Function> Env<'a, F> {
// Handle the def w.r.t. liveranges: trim the
// start of the range and mark it dead at this
// point in our backward scan.
let pos = ProgPoint::before(inst); // See note below re: pos of use.
let pos = ProgPoint::after(inst);
let mut dst_lr = vreg_ranges[dst.vreg()];
// If there was no liverange (dead def), create a trivial one.
if !live.get(dst.vreg()) {
@@ -1319,7 +1319,7 @@ impl<'a, F: Function> Env<'a, F> {
VRegIndex::new(dst.vreg()),
CodeRange {
from: pos,
to: pos.next().next(),
to: pos.next(),
},
&mut num_ranges,
);
@@ -1337,20 +1337,27 @@ impl<'a, F: Function> Env<'a, F> {
vreg_ranges[dst.vreg()] = LiveRangeIndex::invalid();
self.vreg_regs[dst.vreg()] = dst;
let u = UseIndex::new(self.uses.len());
self.uses.push(Use::new(
Operand::new(
dst,
OperandPolicy::Any,
OperandKind::Def,
OperandPos::After,
),
pos,
UseIndex::invalid(),
SLOT_NONE as u8,
));
self.insert_use_into_liverange_and_update_stats(dst_lr, u);
// Handle the use w.r.t. liveranges: make it live
// and create an initial LR back to the start of
// the block.
let pos = ProgPoint::before(inst);
let range = CodeRange {
from: self.cfginfo.block_entry[block.index()],
// Live up to end of previous inst. Because
// the move isn't actually reading the
// value as part of the inst, all we need
// to do is to decide where to join the
// LRs; and we want this to be at an inst
// boundary, not in the middle, so that
// the move-insertion logic remains happy.
to: pos,
to: pos.next(),
};
let src_lr = self.add_liverange_to_vreg(
VRegIndex::new(src.vreg()),
@@ -1361,6 +1368,20 @@ impl<'a, F: Function> Env<'a, F> {
log::debug!(" -> src LR {:?}", src_lr);
let u = UseIndex::new(self.uses.len());
self.uses.push(Use::new(
Operand::new(
dst,
OperandPolicy::Any,
OperandKind::Use,
OperandPos::Before,
),
pos,
UseIndex::invalid(),
SLOT_NONE as u8,
));
self.insert_use_into_liverange_and_update_stats(src_lr, u);
// Add to live-set.
let src_is_dead_after_move = !live.get(src.vreg());
live.set(src.vreg(), true);