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reduce rightward drift, add fixme

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This commit is contained in:
Scott A Carr 2016-08-02 10:46:26 -07:00
parent 62cdbea8c9
commit bda46c21fe
1 changed files with 41 additions and 41 deletions
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82
src/librustc_mir/transform/deaggregator.rs
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@ -31,55 +31,55 @@ fn run_pass<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
None => { return; },
_ => {}
};
// Do not trigger on constants. Could be revised in future
if let MirSource::Fn(_) = source {} else { return; }
let mut curr: usize = 0;
for bb in mir.basic_blocks_mut() {
while let Some(idx) = get_aggregate_statement(curr, &bb.statements) {
// do the replacement
debug!("removing statement {:?}", idx);
let src_info = bb.statements[idx].source_info;
let mut suffix_stmts = bb.statements.split_off(idx);
let orig_stmt = suffix_stmts.remove(0);
let StatementKind::Assign(ref lhs, ref rhs) = orig_stmt.kind;
if let &Rvalue::Aggregate(ref agg_kind, ref operands) = rhs {
if let &AggregateKind::Adt(adt_def, variant, substs) = agg_kind {
let n = bb.statements.len();
bb.statements.reserve(n + operands.len() + suffix_stmts.len());
for (i, op) in operands.iter().enumerate() {
let ref variant_def = adt_def.variants[variant];
let ty = variant_def.fields[variant].ty(tcx, substs);
let rhs = Rvalue::Use(op.clone());
let idx = match get_aggregate_statement(curr, &bb.statements) {
Some(idx) => idx,
None => continue,
};
// do the replacement
debug!("removing statement {:?}", idx);
let src_info = bb.statements[idx].source_info;
let suffix_stmts = bb.statements.split_off(idx+1);
let orig_stmt = bb.statements.pop().unwrap();
let StatementKind::Assign(ref lhs, ref rhs) = orig_stmt.kind;
let (agg_kind, operands) = match rhs {
&Rvalue::Aggregate(ref agg_kind, ref operands) => (agg_kind, operands),
_ => span_bug!(src_info.span, "expected aggregate, not {:?}", rhs),
};
let (adt_def, variant, substs) = match agg_kind {
&AggregateKind::Adt(adt_def, variant, substs) => (adt_def, variant, substs),
_ => span_bug!(src_info.span, "expected struct, not {:?}", rhs),
};
let n = bb.statements.len();
bb.statements.reserve(n + operands.len() + suffix_stmts.len());
for (i, op) in operands.iter().enumerate() {
let ref variant_def = adt_def.variants[variant];
let ty = variant_def.fields[variant].ty(tcx, substs);
let rhs = Rvalue::Use(op.clone());
// since we don't handle enums, we don't need a cast
let lhs_cast = lhs.clone();
// since we don't handle enums, we don't need a cast
let lhs_cast = lhs.clone();
// if we handled enums:
// let lhs_cast = if adt_def.variants.len() > 1 {
// Lvalue::Projection(Box::new(LvalueProjection {
// base: ai.lhs.clone(),
// elem: ProjectionElem::Downcast(ai.adt_def, ai.variant),
// }))
// } else {
// lhs_cast
// };
// FIXME we cannot deaggregate enums issue: 35186
let lhs_proj = Lvalue::Projection(Box::new(LvalueProjection {
base: lhs_cast,
elem: ProjectionElem::Field(Field::new(i), ty),
}));
let new_statement = Statement {
source_info: src_info,
kind: StatementKind::Assign(lhs_proj, rhs),
};
debug!("inserting: {:?} @ {:?}", new_statement, idx + i);
bb.statements.push(new_statement);
}
curr = bb.statements.len();
bb.statements.extend(suffix_stmts);
}
}
let lhs_proj = Lvalue::Projection(Box::new(LvalueProjection {
base: lhs_cast,
elem: ProjectionElem::Field(Field::new(i), ty),
}));
let new_statement = Statement {
source_info: src_info,
kind: StatementKind::Assign(lhs_proj, rhs),
};
debug!("inserting: {:?} @ {:?}", new_statement, idx + i);
bb.statements.push(new_statement);
}
curr = bb.statements.len();
bb.statements.extend(suffix_stmts);
}
}
}