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Fix indent/conditional removal in #108 that removed wrong brace. (#111)

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In #108, we had removed a conditional that became constant-false with
the removal of pinned vregs. Unfortunately, in a pretty embarrassing
text-editing error, I removed the wrong end-brace and re-indented. This
had the effect of moving some of the move-resolution code around in the
regalloc backend, skipping moves in some cases and generating incorrect
results.

Caught as a fuzzbug by OSS-Fuzz in [0] (public after this merges and is
detected as fixed).

[0]: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=55391
This commit is contained in:
Chris Fallin
2023-01-25 13:20:26 -08:00
committed by GitHub
parent 0edb11d3a7
commit 376294e828
1 changed files with 86 additions and 86 deletions
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172
src/ion/moves.rs
View File

@@ -364,101 +364,101 @@ impl<'a, F: Function> Env<'a, F> {
}
block = block.next();
}
// Scan over blocks whose beginnings are covered by
// this range and for which the vreg is live at the
// start of the block. For each, for each predecessor,
// add a Dest half-move.
let mut block = self.cfginfo.insn_block[range.from.inst().index()];
if self.cfginfo.block_entry[block.index()] < range.from {
block = block.next();
// Scan over blocks whose beginnings are covered by
// this range and for which the vreg is live at the
// start of the block. For each, for each predecessor,
// add a Dest half-move.
let mut block = self.cfginfo.insn_block[range.from.inst().index()];
if self.cfginfo.block_entry[block.index()] < range.from {
block = block.next();
}
while block.is_valid() && block.index() < self.func.num_blocks() {
if self.cfginfo.block_entry[block.index()] >= range.to {
break;
}
while block.is_valid() && block.index() < self.func.num_blocks() {
if self.cfginfo.block_entry[block.index()] >= range.to {
// Add half-moves for blockparam inputs.
trace!(
"scanning blockparam_ins at vreg {} block {}: blockparam_in_idx = {}",
vreg.index(),
block.index(),
blockparam_in_idx
);
while blockparam_in_idx < self.blockparam_ins.len() {
let BlockparamIn {
from_block,
to_block,
to_vreg,
} = self.blockparam_ins[blockparam_in_idx];
if (to_vreg, to_block) > (vreg, block) {
break;
}
// Add half-moves for blockparam inputs.
trace!(
"scanning blockparam_ins at vreg {} block {}: blockparam_in_idx = {}",
vreg.index(),
block.index(),
blockparam_in_idx
);
while blockparam_in_idx < self.blockparam_ins.len() {
let BlockparamIn {
from_block,
to_block,
to_vreg,
} = self.blockparam_ins[blockparam_in_idx];
if (to_vreg, to_block) > (vreg, block) {
break;
}
if (to_vreg, to_block) == (vreg, block) {
half_moves.push(HalfMove {
key: half_move_key(
from_block,
to_block,
to_vreg,
HalfMoveKind::Dest,
),
alloc,
});
trace!(
"match: blockparam_in: v{} in block{} from block{} into {}",
to_vreg.index(),
to_block.index(),
from_block.index(),
alloc,
);
#[cfg(debug_assertions)]
if self.annotations_enabled {
self.annotate(
self.cfginfo.block_entry[block.index()],
format!(
"blockparam-in: block{} to block{}:into v{} in {}",
from_block.index(),
to_block.index(),
to_vreg.index(),
alloc
),
);
}
}
blockparam_in_idx += 1;
}
if !self.is_live_in(block, vreg) {
block = block.next();
continue;
}
trace!(
"scanning preds at vreg {} block {} for ends outside the range",
vreg.index(),
block.index()
);
// Now find any preds whose ends are not in the
// same range, and insert appropriate moves.
for &pred in self.func.block_preds(block) {
trace!(
"pred block {} has exit {:?}",
pred.index(),
self.cfginfo.block_exit[pred.index()]
);
if range.contains_point(self.cfginfo.block_exit[pred.index()]) {
continue;
}
trace!(" -> requires half-move");
if (to_vreg, to_block) == (vreg, block) {
half_moves.push(HalfMove {
key: half_move_key(pred, block, vreg, HalfMoveKind::Dest),
key: half_move_key(
from_block,
to_block,
to_vreg,
HalfMoveKind::Dest,
),
alloc,
});
trace!(
"match: blockparam_in: v{} in block{} from block{} into {}",
to_vreg.index(),
to_block.index(),
from_block.index(),
alloc,
);
#[cfg(debug_assertions)]
if self.annotations_enabled {
self.annotate(
self.cfginfo.block_entry[block.index()],
format!(
"blockparam-in: block{} to block{}:into v{} in {}",
from_block.index(),
to_block.index(),
to_vreg.index(),
alloc
),
);
}
}
block = block.next();
blockparam_in_idx += 1;
}
if !self.is_live_in(block, vreg) {
block = block.next();
continue;
}
trace!(
"scanning preds at vreg {} block {} for ends outside the range",
vreg.index(),
block.index()
);
// Now find any preds whose ends are not in the
// same range, and insert appropriate moves.
for &pred in self.func.block_preds(block) {
trace!(
"pred block {} has exit {:?}",
pred.index(),
self.cfginfo.block_exit[pred.index()]
);
if range.contains_point(self.cfginfo.block_exit[pred.index()]) {
continue;
}
trace!(" -> requires half-move");
half_moves.push(HalfMove {
key: half_move_key(pred, block, vreg, HalfMoveKind::Dest),
alloc,
});
}
block = block.next();
}
// Scan over def/uses and apply allocations.