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Merged
merged 5 commits into from
Apr 6, 2022
+193 −4
Merged

New mir-opt deref_separator #95649

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4332b5f
New mir-opt deref_separator
ouz-a Apr 4, 2022
105e90f
fixed error, made function leaner and tighter
ouz-a Apr 4, 2022
904d6c8
destroy temp at the end and avoid ICE
ouz-a Apr 4, 2022
72070d8
remove region check
ouz-a Apr 5, 2022
1cf6d69
kill temp early
ouz-a Apr 5, 2022
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17 changes: 10 additions & 7 deletions compiler/rustc_mir_transform/src/deref_separator.rs
View file
Original file line number Diff line number Diff line change
@@ -8,11 +8,15 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
let mut patch = MirPatch::new(body);
let (basic_blocks, local_decl) = body.basic_blocks_and_local_decls_mut();
for (block, data) in basic_blocks.iter_enumerated_mut() {
let statement_len = data.statements.len();
for (i, stmt) in data.statements.iter_mut().enumerate() {
match stmt.kind {
StatementKind::Assign(box (og_place, Rvalue::Ref(region, borrow_knd, place))) => {
for (idx, (p_ref, p_elem)) in place.iter_projections().enumerate() {
if p_elem == ProjectionElem::Deref && !p_ref.projection.is_empty() {
if p_elem == ProjectionElem::Deref
&& !p_ref.projection.is_empty()
&& region.is_erased()
{
// The type that we are derefing
let ty = p_ref.ty(local_decl, tcx).ty;
let temp = patch.new_temp(ty, stmt.source_info.span);
@@ -36,21 +40,20 @@ pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
// and copying derefed values which we need to create new statement
let temp_place =
Place::from(temp).project_deeper(&place.projection[idx..], tcx);
patch.add_assign(
loc,
og_place,
Rvalue::Ref(region, borrow_knd, temp_place),
);

let new_stmt = Statement {
source_info: stmt.source_info,
kind: StatementKind::Assign(Box::new((
og_place,
Rvalue::Ref(region, borrow_knd, temp_place),
))),
};

// Replace current statement with newly created one
*stmt = new_stmt;

// Since our job with the temp is done it should be gone
let loc = Location { block: block, statement_index: statement_len };
patch.add_statement(loc, StatementKind::StorageDead(temp));
}
}
}
4 changes: 2 additions & 2 deletions src/test/mir-opt/derefer_test.main.Derefer.diff
View file
Original file line number Diff line number Diff line change
@@ -37,19 +37,19 @@
- _4 = &mut ((*(_2.1: &mut (i32, i32))).0: i32); // scope 2 at $DIR/derefer_test.rs:5:13: 5:26
+ StorageLive(_6); // scope 2 at $DIR/derefer_test.rs:5:13: 5:26
+ _6 = move (_2.1: &mut (i32, i32)); // scope 2 at $DIR/derefer_test.rs:5:13: 5:26
+ _4 = &mut ((*_6).0: i32); // scope 2 at $DIR/derefer_test.rs:5:13: 5:26
+ _4 = &mut ((*_6).0: i32); // scope 2 at $DIR/derefer_test.rs:5:13: 5:26
StorageLive(_5); // scope 3 at $DIR/derefer_test.rs:6:9: 6:10
- _5 = &mut ((*(_2.1: &mut (i32, i32))).1: i32); // scope 3 at $DIR/derefer_test.rs:6:13: 6:26
+ StorageLive(_7); // scope 3 at $DIR/derefer_test.rs:6:13: 6:26
+ _7 = move (_2.1: &mut (i32, i32)); // scope 3 at $DIR/derefer_test.rs:6:13: 6:26
+ _5 = &mut ((*_7).1: i32); // scope 3 at $DIR/derefer_test.rs:6:13: 6:26
+ _5 = &mut ((*_7).1: i32); // scope 3 at $DIR/derefer_test.rs:6:13: 6:26
_0 = const (); // scope 0 at $DIR/derefer_test.rs:2:11: 7:2
StorageDead(_5); // scope 3 at $DIR/derefer_test.rs:7:1: 7:2
StorageDead(_4); // scope 2 at $DIR/derefer_test.rs:7:1: 7:2
StorageDead(_2); // scope 1 at $DIR/derefer_test.rs:7:1: 7:2
StorageDead(_1); // scope 0 at $DIR/derefer_test.rs:7:1: 7:2
+ StorageDead(_6); // scope 0 at $DIR/derefer_test.rs:7:2: 7:2
+ StorageDead(_7); // scope 0 at $DIR/derefer_test.rs:7:2: 7:2
return; // scope 0 at $DIR/derefer_test.rs:7:2: 7:2
+ }
+
2 changes: 1 addition & 1 deletion src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir
View file
Original file line number Diff line number Diff line change
@@ -23,11 +23,11 @@ fn b(_1: &mut Box<T>) -> &mut T {
StorageLive(_7); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_7 = move (*_4); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_6 = &mut (*_7); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_6 = &mut (*_7); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_5 = &mut (*_6); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_3 = &mut (*_5); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
StorageDead(_6); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
StorageDead(_5); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
StorageDead(_7); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_2 = &mut (*_3); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
StorageDead(_4); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:14: 8:15
_0 = &mut (*_2); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
2 changes: 1 addition & 1 deletion src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir
View file
Original file line number Diff line number Diff line change
@@ -17,7 +17,7 @@ fn d(_1: &Box<T>) -> &T {
StorageLive(_4); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_4 = move (*_3); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_2 = &(*_4); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_2 = &(*_4); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
StorageDead(_4); // scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
_0 = &(*_2); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:18:5: 18:15
StorageDead(_3); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:18:14: 18:15
StorageDead(_2); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:19:1: 19:2