diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_mir_transform/src/dest_prop.rs | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index 9ba2d274691..7e6f39881b8 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -567,13 +567,15 @@ fn save_as_intervals<'tcx>( // the written-to locals as live in the second half of the statement. // We also ensure that operands read by terminators conflict with writes by that terminator. // For instance a function call may read args after having written to the destination. - VisitPlacesWith(|place, ctxt| match DefUse::for_place(place, ctxt) { - DefUse::Def | DefUse::Use | DefUse::PartialWrite => { - if let Some(relevant) = relevant.shrink[place.local] { - values.insert(relevant, twostep); + VisitPlacesWith(|place: Place<'tcx>, ctxt| { + if let Some(relevant) = relevant.shrink[place.local] { + match DefUse::for_place(place, ctxt) { + DefUse::Def | DefUse::Use | DefUse::PartialWrite => { + values.insert(relevant, twostep); + } + DefUse::NonUse => {} } } - DefUse::NonUse => {} }) .visit_terminator(term, loc); @@ -590,13 +592,20 @@ fn save_as_intervals<'tcx>( append_at(&mut values, &state, twostep); // Ensure we have a non-zero live range even for dead stores. This is done by marking // all the written-to locals as live in the second half of the statement. - VisitPlacesWith(|place, ctxt| match DefUse::for_place(place, ctxt) { - DefUse::Def | DefUse::PartialWrite => { - if let Some(relevant) = relevant.shrink[place.local] { - values.insert(relevant, twostep); + let is_simple_assignment = + matches!(stmt.kind, StatementKind::Assign(box (_, Rvalue::Use(_)))); + VisitPlacesWith(|place: Place<'tcx>, ctxt| { + if let Some(relevant) = relevant.shrink[place.local] { + match DefUse::for_place(place, ctxt) { + DefUse::Def | DefUse::PartialWrite => { + values.insert(relevant, twostep); + } + DefUse::Use if !is_simple_assignment => { + values.insert(relevant, twostep); + } + DefUse::Use | DefUse::NonUse => {} } } - DefUse::Use | DefUse::NonUse => {} }) .visit_statement(stmt, loc); |