Merging upstream version 1.69.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 218 insertions, 54 deletions

diff --git a/tests/mir-opt/dataflow-const-prop/checked.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/checked.main.DataflowConstProp.diff
index a4ebd0c8c..944afed8f 100644
--- a/tests/mir-opt/dataflow-const-prop/checked.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/checked.main.DataflowConstProp.diff
@@ -61,7 +61,7 @@
 -         assert(!move (_10.1: bool), "attempt to compute `{} + {}`, which would overflow", move _9, const 1_i32) -> bb2; // scope 4 at $DIR/checked.rs:+6:13: +6:18
 +         _9 = const i32::MAX;             // scope 4 at $DIR/checked.rs:+6:13: +6:14
 +         _10 = CheckedAdd(const i32::MAX, const 1_i32); // scope 4 at $DIR/checked.rs:+6:13: +6:18
-+         assert(!move (_10.1: bool), "attempt to compute `{} + {}`, which would overflow", const i32::MAX, const 1_i32) -> bb2; // scope 4 at $DIR/checked.rs:+6:13: +6:18
++         assert(!const true, "attempt to compute `{} + {}`, which would overflow", const i32::MAX, const 1_i32) -> bb2; // scope 4 at $DIR/checked.rs:+6:13: +6:18
       }
   
       bb2: {
diff --git a/tests/mir-opt/dataflow-const-prop/enum.multiple.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/enum.multiple.DataflowConstProp.diff
new file mode 100644
index 000000000..c4002d65e
--- /dev/null
+++ b/tests/mir-opt/dataflow-const-prop/enum.multiple.DataflowConstProp.diff
@@ -0,0 +1,82 @@
+- // MIR for `multiple` before DataflowConstProp
++ // MIR for `multiple` after DataflowConstProp
+  
+  fn multiple(_1: bool, _2: u8) -> () {
+      debug x => _1;                       // in scope 0 at $DIR/enum.rs:+0:13: +0:14
+      debug i => _2;                       // in scope 0 at $DIR/enum.rs:+0:22: +0:23
+      let mut _0: ();                      // return place in scope 0 at $DIR/enum.rs:+0:29: +0:29
+      let _3: std::option::Option<u8>;     // in scope 0 at $DIR/enum.rs:+1:9: +1:10
+      let mut _4: bool;                    // in scope 0 at $DIR/enum.rs:+1:16: +1:17
+      let mut _5: u8;                      // in scope 0 at $DIR/enum.rs:+2:14: +2:15
+      let mut _7: isize;                   // in scope 0 at $DIR/enum.rs:+9:23: +9:30
+      scope 1 {
+          debug e => _3;                   // in scope 1 at $DIR/enum.rs:+1:9: +1:10
+          let _6: u8;                      // in scope 1 at $DIR/enum.rs:+9:9: +9:10
+          let _8: u8;                      // in scope 1 at $DIR/enum.rs:+9:28: +9:29
+          scope 2 {
+              debug x => _6;               // in scope 2 at $DIR/enum.rs:+9:9: +9:10
+              let _9: u8;                  // in scope 2 at $DIR/enum.rs:+11:9: +11:10
+              scope 4 {
+                  debug y => _9;           // in scope 4 at $DIR/enum.rs:+11:9: +11:10
+              }
+          }
+          scope 3 {
+              debug i => _8;               // in scope 3 at $DIR/enum.rs:+9:28: +9:29
+          }
+      }
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/enum.rs:+1:9: +1:10
+          StorageLive(_4);                 // scope 0 at $DIR/enum.rs:+1:16: +1:17
+          _4 = _1;                         // scope 0 at $DIR/enum.rs:+1:16: +1:17
+          switchInt(move _4) -> [0: bb2, otherwise: bb1]; // scope 0 at $DIR/enum.rs:+1:16: +1:17
+      }
+  
+      bb1: {
+          StorageLive(_5);                 // scope 0 at $DIR/enum.rs:+2:14: +2:15
+          _5 = _2;                         // scope 0 at $DIR/enum.rs:+2:14: +2:15
+          _3 = Option::<u8>::Some(move _5); // scope 0 at $DIR/enum.rs:+2:9: +2:16
+          StorageDead(_5);                 // scope 0 at $DIR/enum.rs:+2:15: +2:16
+          goto -> bb3;                     // scope 0 at $DIR/enum.rs:+1:13: +5:6
+      }
+  
+      bb2: {
+          _3 = Option::<u8>::None;         // scope 0 at $DIR/enum.rs:+4:9: +4:13
+          goto -> bb3;                     // scope 0 at $DIR/enum.rs:+1:13: +5:6
+      }
+  
+      bb3: {
+          StorageDead(_4);                 // scope 0 at $DIR/enum.rs:+5:5: +5:6
+          StorageLive(_6);                 // scope 1 at $DIR/enum.rs:+9:9: +9:10
+          _7 = discriminant(_3);           // scope 1 at $DIR/enum.rs:+9:19: +9:20
+          switchInt(move _7) -> [0: bb4, 1: bb6, otherwise: bb5]; // scope 1 at $DIR/enum.rs:+9:13: +9:20
+      }
+  
+      bb4: {
+          _6 = const 0_u8;                 // scope 1 at $DIR/enum.rs:+9:45: +9:46
+          goto -> bb7;                     // scope 1 at $DIR/enum.rs:+9:45: +9:46
+      }
+  
+      bb5: {
+          unreachable;                     // scope 1 at $DIR/enum.rs:+9:19: +9:20
+      }
+  
+      bb6: {
+          StorageLive(_8);                 // scope 1 at $DIR/enum.rs:+9:28: +9:29
+          _8 = ((_3 as Some).0: u8);       // scope 1 at $DIR/enum.rs:+9:28: +9:29
+          _6 = _8;                         // scope 3 at $DIR/enum.rs:+9:34: +9:35
+          StorageDead(_8);                 // scope 1 at $DIR/enum.rs:+9:34: +9:35
+          goto -> bb7;                     // scope 1 at $DIR/enum.rs:+9:34: +9:35
+      }
+  
+      bb7: {
+          StorageLive(_9);                 // scope 2 at $DIR/enum.rs:+11:9: +11:10
+          _9 = _6;                         // scope 2 at $DIR/enum.rs:+11:13: +11:14
+          _0 = const ();                   // scope 0 at $DIR/enum.rs:+0:29: +12:2
+          StorageDead(_9);                 // scope 2 at $DIR/enum.rs:+12:1: +12:2
+          StorageDead(_6);                 // scope 1 at $DIR/enum.rs:+12:1: +12:2
+          StorageDead(_3);                 // scope 0 at $DIR/enum.rs:+12:1: +12:2
+          return;                          // scope 0 at $DIR/enum.rs:+12:2: +12:2
+      }
+  }
+  
diff --git a/tests/mir-opt/dataflow-const-prop/enum.mutate_discriminant.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/enum.mutate_discriminant.DataflowConstProp.diff
new file mode 100644
index 000000000..038e6c6bd
--- /dev/null
+++ b/tests/mir-opt/dataflow-const-prop/enum.mutate_discriminant.DataflowConstProp.diff
@@ -0,0 +1,26 @@
+- // MIR for `mutate_discriminant` before DataflowConstProp
++ // MIR for `mutate_discriminant` after DataflowConstProp
+  
+  fn mutate_discriminant() -> u8 {
+      let mut _0: u8;                      // return place in scope 0 at $DIR/enum.rs:+0:29: +0:31
+      let mut _1: std::option::Option<NonZeroUsize>; // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _2: isize;                   // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+  
+      bb0: {
+          discriminant(_1) = 1;            // scope 0 at $DIR/enum.rs:+4:13: +4:34
+          (((_1 as variant#1).0: NonZeroUsize).0: usize) = const 0_usize; // scope 0 at $DIR/enum.rs:+6:13: +6:64
+          _2 = discriminant(_1);           // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          switchInt(_2) -> [0: bb1, otherwise: bb2]; // scope 0 at $DIR/enum.rs:+9:13: +12:14
+      }
+  
+      bb1: {
+          _0 = const 1_u8;                 // scope 0 at $DIR/enum.rs:+15:13: +15:20
+          return;                          // scope 0 at $DIR/enum.rs:+16:13: +16:21
+      }
+  
+      bb2: {
+          _0 = const 2_u8;                 // scope 0 at $DIR/enum.rs:+19:13: +19:20
+          unreachable;                     // scope 0 at $DIR/enum.rs:+20:13: +20:26
+      }
+  }
+  
diff --git a/tests/mir-opt/dataflow-const-prop/enum.rs b/tests/mir-opt/dataflow-const-prop/enum.rs
index 13288577d..79a20d7ef 100644
--- a/tests/mir-opt/dataflow-const-prop/enum.rs
+++ b/tests/mir-opt/dataflow-const-prop/enum.rs
@@ -1,13 +1,68 @@
 // unit-test: DataflowConstProp
 
-// Not trackable, because variants could be aliased.
+#![feature(custom_mir, core_intrinsics, rustc_attrs)]
+
+use std::intrinsics::mir::*;
+
 enum E {
     V1(i32),
     V2(i32)
 }
 
-// EMIT_MIR enum.main.DataflowConstProp.diff
-fn main() {
+// EMIT_MIR enum.simple.DataflowConstProp.diff
+fn simple() {
     let e = E::V1(0);
     let x = match e { E::V1(x) => x, E::V2(x) => x };
 }
+
+#[rustc_layout_scalar_valid_range_start(1)]
+#[rustc_nonnull_optimization_guaranteed]
+struct NonZeroUsize(usize);
+
+// EMIT_MIR enum.mutate_discriminant.DataflowConstProp.diff
+#[custom_mir(dialect = "runtime", phase = "post-cleanup")]
+fn mutate_discriminant() -> u8 {
+    mir!(
+        let x: Option<NonZeroUsize>;
+        {
+            SetDiscriminant(x, 1);
+            // This assignment overwrites the niche in which the discriminant is stored.
+            place!(Field(Field(Variant(x, 1), 0), 0)) = 0_usize;
+            // So we cannot know the value of this discriminant.
+            let a = Discriminant(x);
+            match a {
+                0 => bb1,
+                _ => bad,
+            }
+        }
+        bb1 = {
+            RET = 1;
+            Return()
+        }
+        bad = {
+            RET = 2;
+            Unreachable()
+        }
+    )
+}
+
+// EMIT_MIR enum.multiple.DataflowConstProp.diff
+fn multiple(x: bool, i: u8) {
+    let e = if x {
+        Some(i)
+    } else {
+        None
+    };
+    // The dataflow state must have:
+    //   discriminant(e) => Top
+    //   (e as Some).0 => Top
+    let x = match e { Some(i) => i, None => 0 };
+    // Therefore, `x` should be `Top` here, and no replacement shall happen.
+    let y = x;
+}
+
+fn main() {
+    simple();
+    mutate_discriminant();
+    multiple(false, 5);
+}
diff --git a/tests/mir-opt/dataflow-const-prop/enum.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/enum.simple.DataflowConstProp.diff
index fce18fae4..22bdc35d6 100644
--- a/tests/mir-opt/dataflow-const-prop/enum.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/enum.simple.DataflowConstProp.diff
@@ -1,8 +1,8 @@
-- // MIR for `main` before DataflowConstProp
-+ // MIR for `main` after DataflowConstProp
+- // MIR for `simple` before DataflowConstProp
++ // MIR for `simple` after DataflowConstProp
   
-  fn main() -> () {
-      let mut _0: ();                      // return place in scope 0 at $DIR/enum.rs:+0:11: +0:11
+  fn simple() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/enum.rs:+0:13: +0:13
       let _1: E;                           // in scope 0 at $DIR/enum.rs:+1:9: +1:10
       let mut _3: isize;                   // in scope 0 at $DIR/enum.rs:+2:23: +2:31
       scope 1 {
@@ -23,12 +23,12 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/enum.rs:+1:9: +1:10
-          Deinit(_1);                      // scope 0 at $DIR/enum.rs:+1:13: +1:21
-          ((_1 as V1).0: i32) = const 0_i32; // scope 0 at $DIR/enum.rs:+1:13: +1:21
-          discriminant(_1) = 0;            // scope 0 at $DIR/enum.rs:+1:13: +1:21
+          _1 = E::V1(const 0_i32);         // scope 0 at $DIR/enum.rs:+1:13: +1:21
           StorageLive(_2);                 // scope 1 at $DIR/enum.rs:+2:9: +2:10
-          _3 = discriminant(_1);           // scope 1 at $DIR/enum.rs:+2:19: +2:20
-          switchInt(move _3) -> [0: bb3, 1: bb1, otherwise: bb2]; // scope 1 at $DIR/enum.rs:+2:13: +2:20
+-         _3 = discriminant(_1);           // scope 1 at $DIR/enum.rs:+2:19: +2:20
+-         switchInt(move _3) -> [0: bb3, 1: bb1, otherwise: bb2]; // scope 1 at $DIR/enum.rs:+2:13: +2:20
++         _3 = const 0_isize;              // scope 1 at $DIR/enum.rs:+2:19: +2:20
++         switchInt(const 0_isize) -> [0: bb3, 1: bb1, otherwise: bb2]; // scope 1 at $DIR/enum.rs:+2:13: +2:20
       }
   
       bb1: {
@@ -45,14 +45,16 @@
   
       bb3: {
           StorageLive(_4);                 // scope 1 at $DIR/enum.rs:+2:29: +2:30
-          _4 = ((_1 as V1).0: i32);        // scope 1 at $DIR/enum.rs:+2:29: +2:30
-          _2 = _4;                         // scope 3 at $DIR/enum.rs:+2:35: +2:36
+-         _4 = ((_1 as V1).0: i32);        // scope 1 at $DIR/enum.rs:+2:29: +2:30
+-         _2 = _4;                         // scope 3 at $DIR/enum.rs:+2:35: +2:36
++         _4 = const 0_i32;                // scope 1 at $DIR/enum.rs:+2:29: +2:30
++         _2 = const 0_i32;                // scope 3 at $DIR/enum.rs:+2:35: +2:36
           StorageDead(_4);                 // scope 1 at $DIR/enum.rs:+2:35: +2:36
           goto -> bb4;                     // scope 1 at $DIR/enum.rs:+2:35: +2:36
       }
   
       bb4: {
-          _0 = const ();                   // scope 0 at $DIR/enum.rs:+0:11: +3:2
+          _0 = const ();                   // scope 0 at $DIR/enum.rs:+0:13: +3:2
           StorageDead(_2);                 // scope 1 at $DIR/enum.rs:+3:1: +3:2
           StorageDead(_1);                 // scope 0 at $DIR/enum.rs:+3:1: +3:2
           return;                          // scope 0 at $DIR/enum.rs:+3:2: +3:2
diff --git a/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
index 02aafd7ac..29781e9ce 100644
--- a/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
@@ -5,34 +5,34 @@
       let mut _0: ();                      // return place in scope 0 at $DIR/inherit_overflow.rs:+0:11: +0:11
       let mut _1: u8;                      // in scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
       let mut _2: u8;                      // in scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
+      let mut _3: u8;                      // in scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
       scope 1 {
       }
-      scope 2 (inlined <u8 as Add>::add) { // at $DIR/inherit_overflow.rs:7:13: 7:47
-          debug self => _1;                // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          debug other => _2;               // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          let mut _3: u8;                  // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          let mut _4: u8;                  // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          let mut _5: (u8, bool);          // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+      scope 2 (inlined <u8 as Add>::add) { // at $DIR/inherit_overflow.rs:8:13: 8:47
+          debug self => _2;                // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+          debug other => _3;               // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+          let mut _4: (u8, bool);          // in scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
       }
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          _1 = const u8::MAX;              // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
           StorageLive(_2);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          _2 = const 1_u8;                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          StorageLive(_3);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          _3 = const u8::MAX;              // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          StorageLive(_4);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          _4 = const 1_u8;                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          _5 = CheckedAdd(const u8::MAX, const 1_u8); // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          assert(!move (_5.1: bool), "attempt to compute `{} + {}`, which would overflow", const u8::MAX, const 1_u8) -> bb1; // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+          _2 = const u8::MAX;              // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
+          StorageLive(_3);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
+          _3 = const 1_u8;                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
+-         _4 = CheckedAdd(_2, _3);         // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+-         assert(!move (_4.1: bool), "attempt to compute `{} + {}`, which would overflow", _2, _3) -> bb1; // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
++         _4 = CheckedAdd(const u8::MAX, const 1_u8); // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
++         assert(!const true, "attempt to compute `{} + {}`, which would overflow", const u8::MAX, const 1_u8) -> bb1; // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
       }
   
       bb1: {
-          StorageDead(_4);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          StorageDead(_3);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+-         _1 = move (_4.0: u8);            // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
++         _1 = const 0_u8;                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
+          StorageDead(_3);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
           StorageDead(_2);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          StorageDead(_1);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
+          StorageDead(_1);                 // scope 0 at $DIR/inherit_overflow.rs:+3:47: +3:48
+          _0 = const ();                   // scope 0 at $DIR/inherit_overflow.rs:+0:11: +4:2
           return;                          // scope 0 at $DIR/inherit_overflow.rs:+4:2: +4:2
       }
   }
diff --git a/tests/mir-opt/dataflow-const-prop/inherit_overflow.rs b/tests/mir-opt/dataflow-const-prop/inherit_overflow.rs
index 2f2d9d010..f4aba60f0 100644
--- a/tests/mir-opt/dataflow-const-prop/inherit_overflow.rs
+++ b/tests/mir-opt/dataflow-const-prop/inherit_overflow.rs
@@ -1,8 +1,9 @@
-// compile-flags: -Zunsound-mir-opts
+// unit-test: DataflowConstProp
+// compile-flags: -Zmir-enable-passes=+Inline
 
 // EMIT_MIR inherit_overflow.main.DataflowConstProp.diff
 fn main() {
-    // After inlining, this will contain a `CheckedBinaryOp`. The overflow
-    // must be ignored by the constant propagation to avoid triggering a panic.
+    // After inlining, this will contain a `CheckedBinaryOp`.
+    // Propagating the overflow is ok as codegen will just skip emitting the panic.
     let _ = <u8 as std::ops::Add>::add(255, 1);
 }
diff --git a/tests/mir-opt/dataflow-const-prop/repr_transparent.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/repr_transparent.main.DataflowConstProp.diff
index f66b00a9a..8f045eedf 100644
--- a/tests/mir-opt/dataflow-const-prop/repr_transparent.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/repr_transparent.main.DataflowConstProp.diff
@@ -17,8 +17,7 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/repr_transparent.rs:+1:9: +1:10
-          Deinit(_1);                      // scope 0 at $DIR/repr_transparent.rs:+1:13: +1:19
-          (_1.0: i32) = const 0_i32;       // scope 0 at $DIR/repr_transparent.rs:+1:13: +1:19
+          _1 = I32(const 0_i32);           // scope 0 at $DIR/repr_transparent.rs:+1:13: +1:19
           StorageLive(_2);                 // scope 1 at $DIR/repr_transparent.rs:+2:9: +2:10
           StorageLive(_3);                 // scope 1 at $DIR/repr_transparent.rs:+2:17: +2:26
           StorageLive(_4);                 // scope 1 at $DIR/repr_transparent.rs:+2:17: +2:20
@@ -31,9 +30,8 @@
 +         _3 = const 0_i32;                // scope 1 at $DIR/repr_transparent.rs:+2:17: +2:26
           StorageDead(_5);                 // scope 1 at $DIR/repr_transparent.rs:+2:25: +2:26
           StorageDead(_4);                 // scope 1 at $DIR/repr_transparent.rs:+2:25: +2:26
-          Deinit(_2);                      // scope 1 at $DIR/repr_transparent.rs:+2:13: +2:27
--         (_2.0: i32) = move _3;           // scope 1 at $DIR/repr_transparent.rs:+2:13: +2:27
-+         (_2.0: i32) = const 0_i32;       // scope 1 at $DIR/repr_transparent.rs:+2:13: +2:27
+-         _2 = I32(move _3);               // scope 1 at $DIR/repr_transparent.rs:+2:13: +2:27
++         _2 = I32(const 0_i32);           // scope 1 at $DIR/repr_transparent.rs:+2:13: +2:27
           StorageDead(_3);                 // scope 1 at $DIR/repr_transparent.rs:+2:26: +2:27
           _0 = const ();                   // scope 0 at $DIR/repr_transparent.rs:+0:11: +3:2
           StorageDead(_2);                 // scope 1 at $DIR/repr_transparent.rs:+3:1: +3:2
diff --git a/tests/mir-opt/dataflow-const-prop/sibling_ptr.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/sibling_ptr.main.DataflowConstProp.diff
index 8126d4b85..004643e36 100644
--- a/tests/mir-opt/dataflow-const-prop/sibling_ptr.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/sibling_ptr.main.DataflowConstProp.diff
@@ -23,9 +23,7 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/sibling_ptr.rs:+1:9: +1:14
-          Deinit(_1);                      // scope 0 at $DIR/sibling_ptr.rs:+1:27: +1:33
-          (_1.0: u8) = const 0_u8;         // scope 0 at $DIR/sibling_ptr.rs:+1:27: +1:33
-          (_1.1: u8) = const 0_u8;         // scope 0 at $DIR/sibling_ptr.rs:+1:27: +1:33
+          _1 = (const 0_u8, const 0_u8);   // scope 0 at $DIR/sibling_ptr.rs:+1:27: +1:33
           StorageLive(_2);                 // scope 1 at $DIR/sibling_ptr.rs:+2:5: +5:6
           StorageLive(_3);                 // scope 2 at $DIR/sibling_ptr.rs:+3:13: +3:14
           _3 = &raw mut (_1.0: u8);        // scope 2 at $SRC_DIR/core/src/ptr/mod.rs:LL:COL
@@ -34,7 +32,7 @@
           _5 = _3;                         // scope 3 at $DIR/sibling_ptr.rs:+4:10: +4:11
           _4 = ptr::mut_ptr::<impl *mut u8>::add(move _5, const 1_usize) -> bb1; // scope 3 at $DIR/sibling_ptr.rs:+4:10: +4:18
                                            // mir::Constant
-                                           // + span: $DIR/sibling_ptr.rs:8:12: 8:15
+                                           // + span: $DIR/sibling_ptr.rs:15:12: 15:15
                                            // + literal: Const { ty: unsafe fn(*mut u8, usize) -> *mut u8 {ptr::mut_ptr::<impl *mut u8>::add}, val: Value(<ZST>) }
       }
   
diff --git a/tests/mir-opt/dataflow-const-prop/sibling_ptr.rs b/tests/mir-opt/dataflow-const-prop/sibling_ptr.rs
index 87ef00d18..6dfb3a4ed 100644
--- a/tests/mir-opt/dataflow-const-prop/sibling_ptr.rs
+++ b/tests/mir-opt/dataflow-const-prop/sibling_ptr.rs
@@ -1,3 +1,10 @@
+// This attempts to modify `x.1` via a pointer derived from `addr_of_mut!(x.0)`.
+// According to Miri, that is UB. However, T-opsem has not finalized that
+// decision and as such we cannot rely on it in optimizations. Consequently,
+// DataflowConstProp must treat the `addr_of_mut!(x.0)` as potentially being
+// used to modify `x.1` - if it did not, then it might incorrectly assume that it
+// can infer the value of `x.1` at the end of this function.
+
 // unit-test: DataflowConstProp
 
 // EMIT_MIR sibling_ptr.main.DataflowConstProp.diff
@@ -7,5 +14,5 @@ fn main() {
         let p = std::ptr::addr_of_mut!(x.0);
         *p.add(1) = 1;
     }
-    let x1 = x.1;  // should not be propagated
+    let x1 = x.1; // should not be propagated
 }
diff --git a/tests/mir-opt/dataflow-const-prop/struct.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/struct.main.DataflowConstProp.diff
index cfb2706c1..53c62c081 100644
--- a/tests/mir-opt/dataflow-const-prop/struct.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/struct.main.DataflowConstProp.diff
@@ -21,8 +21,7 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/struct.rs:+1:9: +1:14
-          Deinit(_1);                      // scope 0 at $DIR/struct.rs:+1:17: +1:21
-          (_1.0: i32) = const 1_i32;       // scope 0 at $DIR/struct.rs:+1:17: +1:21
+          _1 = S(const 1_i32);             // scope 0 at $DIR/struct.rs:+1:17: +1:21
           StorageLive(_2);                 // scope 1 at $DIR/struct.rs:+2:9: +2:10
           StorageLive(_3);                 // scope 1 at $DIR/struct.rs:+2:13: +2:16
 -         _3 = (_1.0: i32);                // scope 1 at $DIR/struct.rs:+2:13: +2:16
diff --git a/tests/mir-opt/dataflow-const-prop/tuple.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/tuple.main.DataflowConstProp.diff
index e028def00..8ce4ce4ba 100644
--- a/tests/mir-opt/dataflow-const-prop/tuple.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/tuple.main.DataflowConstProp.diff
@@ -25,9 +25,7 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/tuple.rs:+1:9: +1:14
-          Deinit(_1);                      // scope 0 at $DIR/tuple.rs:+1:17: +1:23
-          (_1.0: i32) = const 1_i32;       // scope 0 at $DIR/tuple.rs:+1:17: +1:23
-          (_1.1: i32) = const 2_i32;       // scope 0 at $DIR/tuple.rs:+1:17: +1:23
+          _1 = (const 1_i32, const 2_i32); // scope 0 at $DIR/tuple.rs:+1:17: +1:23
           StorageLive(_2);                 // scope 1 at $DIR/tuple.rs:+2:9: +2:10
           StorageLive(_3);                 // scope 1 at $DIR/tuple.rs:+2:13: +2:22
           StorageLive(_4);                 // scope 1 at $DIR/tuple.rs:+2:13: +2:16
@@ -43,9 +41,7 @@
 -         _2 = Add(move _3, const 3_i32);  // scope 1 at $DIR/tuple.rs:+2:13: +2:26
 +         _2 = const 6_i32;                // scope 1 at $DIR/tuple.rs:+2:13: +2:26
           StorageDead(_3);                 // scope 1 at $DIR/tuple.rs:+2:25: +2:26
-          Deinit(_1);                      // scope 2 at $DIR/tuple.rs:+3:5: +3:15
-          (_1.0: i32) = const 2_i32;       // scope 2 at $DIR/tuple.rs:+3:5: +3:15
-          (_1.1: i32) = const 3_i32;       // scope 2 at $DIR/tuple.rs:+3:5: +3:15
+          _1 = (const 2_i32, const 3_i32); // scope 2 at $DIR/tuple.rs:+3:5: +3:15
           StorageLive(_6);                 // scope 2 at $DIR/tuple.rs:+4:9: +4:10
           StorageLive(_7);                 // scope 2 at $DIR/tuple.rs:+4:13: +4:22
           StorageLive(_8);                 // scope 2 at $DIR/tuple.rs:+4:13: +4:16