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cjgillotcjgillot
committed
Dereference immutable borrows in GVN.
1 parent 73db12a commit 9b846d4

10 files changed

+87
-47
lines changed

‎compiler/rustc_mir_transform/src/gvn.rs

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -724,6 +724,14 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
724724
// Invariant: `value` holds the value up-to the `index`th projection excluded.
725725
let mut value = self.locals[place.local]?;
726726
for (index, proj) in place.projection.iter().enumerate() {
727+
if let Value::Projection(pointer, ProjectionElem::Deref) = *self.get(value)
728+
&& let Value::Address { place: mut pointee, kind, .. } = *self.get(pointer)
729+
&& let AddressKind::Ref(BorrowKind::Shared) = kind
730+
&& let Some(v) = self.simplify_place_value(&mut pointee, location)
731+
{
732+
value = v;
733+
place_ref = pointee.project_deeper(&place.projection[index..], self.tcx).as_ref();
734+
}
727735
if let Some(local) = self.try_as_local(value, location) {
728736
// Both `local` and `Place { local: place.local, projection: projection[..index] }`
729737
// hold the same value. Therefore, following place holds the value in the original
@@ -735,6 +743,14 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
735743
value = self.project(base, value, proj)?;
736744
}
737745

746+
if let Value::Projection(pointer, ProjectionElem::Deref) = *self.get(value)
747+
&& let Value::Address { place: mut pointee, kind, .. } = *self.get(pointer)
748+
&& let AddressKind::Ref(BorrowKind::Shared) = kind
749+
&& let Some(v) = self.simplify_place_value(&mut pointee, location)
750+
{
751+
value = v;
752+
place_ref = pointee.project_deeper(&[], self.tcx).as_ref();
753+
}
738754
if let Some(new_local) = self.try_as_local(value, location) {
739755
place_ref = PlaceRef { local: new_local, projection: &[] };
740756
}

‎tests/coverage/issue-83601.cov-map

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,12 +1,12 @@
11
Function name: issue_83601::main
2-
Raw bytes (21): 0x[01, 01, 01, 05, 09, 03, 01, 06, 01, 02, 1c, 05, 03, 09, 01, 1c, 02, 02, 05, 03, 02]
2+
Raw bytes (21): 0x[01, 01, 01, 05, 00, 03, 01, 06, 01, 02, 1c, 05, 03, 09, 01, 1c, 02, 02, 05, 03, 02]
33
Number of files: 1
44
- file 0 => global file 1
55
Number of expressions: 1
6-
- expression 0 operands: lhs = Counter(1), rhs = Counter(2)
6+
- expression 0 operands: lhs = Counter(1), rhs = Zero
77
Number of file 0 mappings: 3
88
- Code(Counter(0)) at (prev + 6, 1) to (start + 2, 28)
99
- Code(Counter(1)) at (prev + 3, 9) to (start + 1, 28)
1010
- Code(Expression(0, Sub)) at (prev + 2, 5) to (start + 3, 2)
11-
= (c1 - c2)
11+
= (c1 - Zero)
1212

‎tests/coverage/issue-84561.cov-map

Lines changed: 11 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -77,22 +77,22 @@ Number of file 0 mappings: 1
7777
- Code(Counter(0)) at (prev + 167, 9) to (start + 2, 10)
7878

7979
Function name: issue_84561::test3
80-
Raw bytes (436): 0x[01, 01, 41, 05, 09, 0d, 00, 15, 19, 12, 00, 15, 19, 21, 00, 1e, 00, 21, 00, 31, 00, 3d, 41, 2e, 45, 3d, 41, 42, 49, 45, 00, 3f, 51, 42, 49, 45, 00, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 92, 01, 55, 51, 00, 8f, 01, 5d, 92, 01, 55, 51, 00, 87, 01, 61, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 82, 01, 65, 87, 01, 61, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, 00, fe, 01, 82, 02, 00, 69, 6d, 69, 6d, 82, 02, 00, 69, 6d, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, f3, 01, 7d, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, ee, 01, 00, f3, 01, 7d, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, 33, 01, 08, 01, 03, 1c, 05, 04, 09, 01, 1c, 02, 02, 05, 04, 1f, 0d, 05, 05, 00, 1f, 06, 01, 05, 00, 1f, 15, 01, 09, 01, 1c, 12, 02, 05, 00, 1f, 0e, 01, 05, 00, 0f, 00, 00, 20, 00, 30, 21, 01, 05, 03, 0f, 00, 03, 20, 00, 30, 00, 00, 33, 00, 41, 00, 00, 4b, 00, 5a, 1e, 01, 05, 00, 0f, 00, 05, 09, 03, 10, 00, 05, 0d, 00, 1b, 00, 02, 0d, 00, 1c, 1a, 04, 09, 05, 06, 31, 06, 05, 03, 06, 22, 04, 05, 03, 06, 3d, 04, 09, 04, 06, 2e, 05, 08, 00, 0f, 45, 01, 09, 03, 0a, 2a, 05, 09, 03, 0a, 3f, 05, 08, 00, 0f, 51, 01, 09, 00, 13, 00, 03, 0d, 00, 1d, 3a, 03, 09, 00, 13, 00, 03, 0d, 00, 1d, 87, 01, 03, 05, 00, 0f, 8f, 01, 01, 0c, 00, 13, 5d, 01, 0d, 00, 13, 8a, 01, 02, 0d, 00, 13, 82, 01, 04, 05, 02, 13, 65, 03, 0d, 00, 13, 7e, 02, 0d, 00, 13, f3, 01, 03, 05, 00, 0f, 69, 01, 0c, 00, 13, 6d, 01, 0d, 03, 0e, 75, 04, 0d, 00, 13, fb, 01, 02, 0d, 00, 17, 82, 02, 01, 14, 00, 1b, 00, 01, 15, 00, 1b, fe, 01, 02, 15, 00, 1b, f6, 01, 04, 0d, 00, 13, 7d, 03, 09, 00, 19, ee, 01, 02, 05, 00, 0f, ea, 01, 03, 09, 00, 22, 00, 02, 05, 00, 0f, 00, 03, 09, 00, 2c, 00, 02, 01, 00, 02]
80+
Raw bytes (436): 0x[01, 01, 41, 05, 00, 0d, 00, 15, 00, 12, 00, 15, 00, 21, 00, 1e, 00, 21, 00, 31, 00, 3d, 00, 2e, 45, 3d, 00, 42, 49, 45, 00, 3f, 51, 42, 49, 45, 00, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 92, 01, 55, 51, 00, 8f, 01, 5d, 92, 01, 55, 51, 00, 87, 01, 61, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 82, 01, 65, 87, 01, 61, 5d, 8a, 01, 8f, 01, 5d, 92, 01, 55, 51, 00, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, 00, fe, 01, 82, 02, 00, 69, 6d, 69, 6d, 82, 02, 00, 69, 6d, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, f3, 01, 7d, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, ee, 01, 00, f3, 01, 7d, 75, f6, 01, fb, 01, 79, 00, fe, 01, 82, 02, 00, 69, 6d, 33, 01, 08, 01, 03, 1c, 05, 04, 09, 01, 1c, 02, 02, 05, 04, 1f, 0d, 05, 05, 00, 1f, 06, 01, 05, 00, 1f, 15, 01, 09, 01, 1c, 12, 02, 05, 00, 1f, 0e, 01, 05, 00, 0f, 00, 00, 20, 00, 30, 21, 01, 05, 03, 0f, 00, 03, 20, 00, 30, 00, 00, 33, 00, 41, 00, 00, 4b, 00, 5a, 1e, 01, 05, 00, 0f, 00, 05, 09, 03, 10, 00, 05, 0d, 00, 1b, 00, 02, 0d, 00, 1c, 1a, 04, 09, 05, 06, 31, 06, 05, 03, 06, 22, 04, 05, 03, 06, 3d, 04, 09, 04, 06, 2e, 05, 08, 00, 0f, 45, 01, 09, 03, 0a, 2a, 05, 09, 03, 0a, 3f, 05, 08, 00, 0f, 51, 01, 09, 00, 13, 00, 03, 0d, 00, 1d, 3a, 03, 09, 00, 13, 00, 03, 0d, 00, 1d, 87, 01, 03, 05, 00, 0f, 8f, 01, 01, 0c, 00, 13, 5d, 01, 0d, 00, 13, 8a, 01, 02, 0d, 00, 13, 82, 01, 04, 05, 02, 13, 65, 03, 0d, 00, 13, 7e, 02, 0d, 00, 13, f3, 01, 03, 05, 00, 0f, 69, 01, 0c, 00, 13, 6d, 01, 0d, 03, 0e, 75, 04, 0d, 00, 13, fb, 01, 02, 0d, 00, 17, 82, 02, 01, 14, 00, 1b, 00, 01, 15, 00, 1b, fe, 01, 02, 15, 00, 1b, f6, 01, 04, 0d, 00, 13, 7d, 03, 09, 00, 19, ee, 01, 02, 05, 00, 0f, ea, 01, 03, 09, 00, 22, 00, 02, 05, 00, 0f, 00, 03, 09, 00, 2c, 00, 02, 01, 00, 02]
8181
Number of files: 1
8282
- file 0 => global file 1
8383
Number of expressions: 65
84-
- expression 0 operands: lhs = Counter(1), rhs = Counter(2)
84+
- expression 0 operands: lhs = Counter(1), rhs = Zero
8585
- expression 1 operands: lhs = Counter(3), rhs = Zero
86-
- expression 2 operands: lhs = Counter(5), rhs = Counter(6)
86+
- expression 2 operands: lhs = Counter(5), rhs = Zero
8787
- expression 3 operands: lhs = Expression(4, Sub), rhs = Zero
88-
- expression 4 operands: lhs = Counter(5), rhs = Counter(6)
88+
- expression 4 operands: lhs = Counter(5), rhs = Zero
8989
- expression 5 operands: lhs = Counter(8), rhs = Zero
9090
- expression 6 operands: lhs = Expression(7, Sub), rhs = Zero
9191
- expression 7 operands: lhs = Counter(8), rhs = Zero
9292
- expression 8 operands: lhs = Counter(12), rhs = Zero
93-
- expression 9 operands: lhs = Counter(15), rhs = Counter(16)
93+
- expression 9 operands: lhs = Counter(15), rhs = Zero
9494
- expression 10 operands: lhs = Expression(11, Sub), rhs = Counter(17)
95-
- expression 11 operands: lhs = Counter(15), rhs = Counter(16)
95+
- expression 11 operands: lhs = Counter(15), rhs = Zero
9696
- expression 12 operands: lhs = Expression(16, Sub), rhs = Counter(18)
9797
- expression 13 operands: lhs = Counter(17), rhs = Zero
9898
- expression 14 operands: lhs = Expression(15, Add), rhs = Counter(20)
@@ -150,15 +150,15 @@ Number of file 0 mappings: 51
150150
- Code(Counter(0)) at (prev + 8, 1) to (start + 3, 28)
151151
- Code(Counter(1)) at (prev + 4, 9) to (start + 1, 28)
152152
- Code(Expression(0, Sub)) at (prev + 2, 5) to (start + 4, 31)
153-
= (c1 - c2)
153+
= (c1 - Zero)
154154
- Code(Counter(3)) at (prev + 5, 5) to (start + 0, 31)
155155
- Code(Expression(1, Sub)) at (prev + 1, 5) to (start + 0, 31)
156156
= (c3 - Zero)
157157
- Code(Counter(5)) at (prev + 1, 9) to (start + 1, 28)
158158
- Code(Expression(4, Sub)) at (prev + 2, 5) to (start + 0, 31)
159-
= (c5 - c6)
159+
= (c5 - Zero)
160160
- Code(Expression(3, Sub)) at (prev + 1, 5) to (start + 0, 15)
161-
= ((c5 - c6) - Zero)
161+
= ((c5 - Zero) - Zero)
162162
- Code(Zero) at (prev + 0, 32) to (start + 0, 48)
163163
- Code(Counter(8)) at (prev + 1, 5) to (start + 3, 15)
164164
- Code(Zero) at (prev + 3, 32) to (start + 0, 48)
@@ -176,10 +176,10 @@ Number of file 0 mappings: 51
176176
= (c12 - Zero)
177177
- Code(Counter(15)) at (prev + 4, 9) to (start + 4, 6)
178178
- Code(Expression(11, Sub)) at (prev + 5, 8) to (start + 0, 15)
179-
= (c15 - c16)
179+
= (c15 - Zero)
180180
- Code(Counter(17)) at (prev + 1, 9) to (start + 3, 10)
181181
- Code(Expression(10, Sub)) at (prev + 5, 9) to (start + 3, 10)
182-
= ((c15 - c16) - c17)
182+
= ((c15 - Zero) - c17)
183183
- Code(Expression(15, Add)) at (prev + 5, 8) to (start + 0, 15)
184184
= ((c17 - Zero) + c18)
185185
- Code(Counter(20)) at (prev + 1, 9) to (start + 0, 19)

‎tests/mir-opt/gvn.borrowed.GVN.panic-abort.diff

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,8 @@
1818
}
1919

2020
bb2: {
21-
_0 = opaque::<u32>((*_3)) -> [return: bb3, unwind unreachable];
21+
- _0 = opaque::<u32>((*_3)) -> [return: bb3, unwind unreachable];
22+
+ _0 = opaque::<u32>(_1) -> [return: bb3, unwind unreachable];
2223
}
2324

2425
bb3: {

‎tests/mir-opt/gvn.borrowed.GVN.panic-unwind.diff

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,8 @@
1818
}
1919

2020
bb2: {
21-
_0 = opaque::<u32>((*_3)) -> [return: bb3, unwind continue];
21+
- _0 = opaque::<u32>((*_3)) -> [return: bb3, unwind continue];
22+
+ _0 = opaque::<u32>(_1) -> [return: bb3, unwind continue];
2223
}
2324

2425
bb3: {

‎tests/mir-opt/gvn.rs

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -730,7 +730,7 @@ fn borrowed(x: u32) {
730730
// CHECK: bb1: {
731731
// CHECK-NEXT: _0 = opaque::<u32>(_1)
732732
// CHECK: bb2: {
733-
// CHECK-NEXT: _0 = opaque::<u32>((*_3))
733+
// CHECK-NEXT: _0 = opaque::<u32>(_1)
734734
mir!(
735735
{
736736
let a = x;

‎tests/mir-opt/gvn.slices.GVN.panic-abort.diff

Lines changed: 24 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -111,8 +111,9 @@
111111
StorageLive(_7);
112112
StorageLive(_8);
113113
- StorageLive(_9);
114+
- StorageLive(_10);
115+
+ nop;
114116
+ nop;
115-
StorageLive(_10);
116117
StorageLive(_11);
117118
_11 = &(*_1);
118119
_10 = core::str::<impl str>::as_ptr(move _11) -> [return: bb3, unwind unreachable];
@@ -122,8 +123,9 @@
122123
StorageDead(_11);
123124
_9 = &_10;
124125
- StorageLive(_12);
126+
- StorageLive(_13);
127+
+ nop;
125128
+ nop;
126-
StorageLive(_13);
127129
StorageLive(_14);
128130
- _14 = &(*_4);
129131
+ _14 = &(*_1);
@@ -148,11 +150,12 @@
148150
StorageLive(_17);
149151
StorageLive(_18);
150152
- _18 = (*_15);
151-
+ _18 = (*_9);
153+
+ _18 = _10;
152154
StorageLive(_19);
153155
- _19 = (*_16);
154-
+ _19 = (*_12);
155-
_17 = Eq(move _18, move _19);
156+
- _17 = Eq(move _18, move _19);
157+
+ _19 = _13;
158+
+ _17 = Eq(_10, _13);
156159
switchInt(move _17) -> [0: bb6, otherwise: bb5];
157160
}
158161

@@ -163,8 +166,10 @@
163166
StorageDead(_17);
164167
StorageDead(_16);
165168
StorageDead(_15);
166-
StorageDead(_13);
167-
StorageDead(_10);
169+
- StorageDead(_13);
170+
- StorageDead(_10);
171+
+ nop;
172+
+ nop;
168173
StorageDead(_8);
169174
StorageDead(_7);
170175
- StorageLive(_29);
@@ -213,8 +218,9 @@
213218
StorageLive(_33);
214219
StorageLive(_34);
215220
- StorageLive(_35);
221+
- StorageLive(_36);
222+
+ nop;
216223
+ nop;
217-
StorageLive(_36);
218224
StorageLive(_37);
219225
_37 = &(*_1);
220226
_36 = core::str::<impl str>::as_ptr(move _37) -> [return: bb8, unwind unreachable];
@@ -224,8 +230,9 @@
224230
StorageDead(_37);
225231
_35 = &_36;
226232
- StorageLive(_38);
233+
- StorageLive(_39);
234+
+ nop;
227235
+ nop;
228-
StorageLive(_39);
229236
StorageLive(_40);
230237
_40 = &(*_29);
231238
_39 = core::slice::<impl [u8]>::as_ptr(move _40) -> [return: bb9, unwind unreachable];
@@ -249,11 +256,12 @@
249256
StorageLive(_43);
250257
StorageLive(_44);
251258
- _44 = (*_41);
252-
+ _44 = (*_35);
259+
+ _44 = _36;
253260
StorageLive(_45);
254261
- _45 = (*_42);
255-
+ _45 = (*_38);
256-
_43 = Eq(move _44, move _45);
262+
- _43 = Eq(move _44, move _45);
263+
+ _45 = _39;
264+
+ _43 = Eq(_36, _39);
257265
switchInt(move _43) -> [0: bb11, otherwise: bb10];
258266
}
259267

@@ -264,8 +272,10 @@
264272
StorageDead(_43);
265273
StorageDead(_42);
266274
StorageDead(_41);
267-
StorageDead(_39);
268-
StorageDead(_36);
275+
- StorageDead(_39);
276+
- StorageDead(_36);
277+
+ nop;
278+
+ nop;
269279
StorageDead(_34);
270280
StorageDead(_33);
271281
_0 = const ();

‎tests/mir-opt/gvn.slices.GVN.panic-unwind.diff

Lines changed: 24 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -111,8 +111,9 @@
111111
StorageLive(_7);
112112
StorageLive(_8);
113113
- StorageLive(_9);
114+
- StorageLive(_10);
115+
+ nop;
114116
+ nop;
115-
StorageLive(_10);
116117
StorageLive(_11);
117118
_11 = &(*_1);
118119
_10 = core::str::<impl str>::as_ptr(move _11) -> [return: bb3, unwind continue];
@@ -122,8 +123,9 @@
122123
StorageDead(_11);
123124
_9 = &_10;
124125
- StorageLive(_12);
126+
- StorageLive(_13);
127+
+ nop;
125128
+ nop;
126-
StorageLive(_13);
127129
StorageLive(_14);
128130
- _14 = &(*_4);
129131
+ _14 = &(*_1);
@@ -148,11 +150,12 @@
148150
StorageLive(_17);
149151
StorageLive(_18);
150152
- _18 = (*_15);
151-
+ _18 = (*_9);
153+
+ _18 = _10;
152154
StorageLive(_19);
153155
- _19 = (*_16);
154-
+ _19 = (*_12);
155-
_17 = Eq(move _18, move _19);
156+
- _17 = Eq(move _18, move _19);
157+
+ _19 = _13;
158+
+ _17 = Eq(_10, _13);
156159
switchInt(move _17) -> [0: bb6, otherwise: bb5];
157160
}
158161

@@ -163,8 +166,10 @@
163166
StorageDead(_17);
164167
StorageDead(_16);
165168
StorageDead(_15);
166-
StorageDead(_13);
167-
StorageDead(_10);
169+
- StorageDead(_13);
170+
- StorageDead(_10);
171+
+ nop;
172+
+ nop;
168173
StorageDead(_8);
169174
StorageDead(_7);
170175
- StorageLive(_29);
@@ -213,8 +218,9 @@
213218
StorageLive(_33);
214219
StorageLive(_34);
215220
- StorageLive(_35);
221+
- StorageLive(_36);
222+
+ nop;
216223
+ nop;
217-
StorageLive(_36);
218224
StorageLive(_37);
219225
_37 = &(*_1);
220226
_36 = core::str::<impl str>::as_ptr(move _37) -> [return: bb8, unwind continue];
@@ -224,8 +230,9 @@
224230
StorageDead(_37);
225231
_35 = &_36;
226232
- StorageLive(_38);
233+
- StorageLive(_39);
234+
+ nop;
227235
+ nop;
228-
StorageLive(_39);
229236
StorageLive(_40);
230237
_40 = &(*_29);
231238
_39 = core::slice::<impl [u8]>::as_ptr(move _40) -> [return: bb9, unwind continue];
@@ -249,11 +256,12 @@
249256
StorageLive(_43);
250257
StorageLive(_44);
251258
- _44 = (*_41);
252-
+ _44 = (*_35);
259+
+ _44 = _36;
253260
StorageLive(_45);
254261
- _45 = (*_42);
255-
+ _45 = (*_38);
256-
_43 = Eq(move _44, move _45);
262+
- _43 = Eq(move _44, move _45);
263+
+ _45 = _39;
264+
+ _43 = Eq(_36, _39);
257265
switchInt(move _43) -> [0: bb11, otherwise: bb10];
258266
}
259267

@@ -264,8 +272,10 @@
264272
StorageDead(_43);
265273
StorageDead(_42);
266274
StorageDead(_41);
267-
StorageDead(_39);
268-
StorageDead(_36);
275+
- StorageDead(_39);
276+
- StorageDead(_36);
277+
+ nop;
278+
+ nop;
269279
StorageDead(_34);
270280
StorageDead(_33);
271281
_0 = const ();

‎tests/mir-opt/gvn_uninhabited.f.GVN.panic-abort.diff

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,8 @@
1717
StorageLive(_3);
1818
_5 = const f::promoted[0];
1919
_3 = &(*_5);
20-
_2 = ((*_3).1: E);
20+
- _2 = ((*_3).1: E);
21+
+ _2 = ((*_5).1: E);
2122
StorageLive(_1);
2223
- _1 = ((_2 as A).1: u32);
2324
+ _1 = const 0_u32;

‎tests/mir-opt/gvn_uninhabited.f.GVN.panic-unwind.diff

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,8 @@
1717
StorageLive(_3);
1818
_5 = const f::promoted[0];
1919
_3 = &(*_5);
20-
_2 = ((*_3).1: E);
20+
- _2 = ((*_3).1: E);
21+
+ _2 = ((*_5).1: E);
2122
StorageLive(_1);
2223
- _1 = ((_2 as A).1: u32);
2324
+ _1 = const 0_u32;

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