Auto merge of #76659 - simonvandel:76432, r=oli-obk

SimplifyComparisonIntegral: fix miscompilation

Fixes #76432
Only insert StorageDeads if we actually removed one.
Fixes an issue where we added StorageDead to a place with no StorageLive

r? `@oli-obk`

2 files changed, 132 insertions, 0 deletions

diff --git a/src/test/mir-opt/issue_76432.rs b/src/test/mir-opt/issue_76432.rs
new file mode 100644
index 00000000000..c8b405ca8ea
--- /dev/null
+++ b/src/test/mir-opt/issue_76432.rs
@@ -0,0 +1,16 @@
+// Check that we do not insert StorageDead at each target if StorageDead was never seen
+
+// EMIT_MIR issue_76432.test.SimplifyComparisonIntegral.diff
+use std::fmt::Debug;
+
+fn test<T: Copy + Debug + PartialEq>(x: T) {
+    let v: &[T] = &[x, x, x];
+    match v {
+        [ref v1, ref v2, ref v3] => [v1 as *const _, v2 as *const _, v3 as *const _],
+        _ => unreachable!(),
+    };
+}
+
+fn main() {
+    test(0u32);
+}
diff --git a/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
new file mode 100644
index 00000000000..499134b6991
--- /dev/null
+++ b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
@@ -0,0 +1,116 @@
+- // MIR for `test` before SimplifyComparisonIntegral
++ // MIR for `test` after SimplifyComparisonIntegral
+  
+  fn test(_1: T) -> () {
+      debug x => _1;                       // in scope 0 at $DIR/issue_76432.rs:6:38: 6:39
+      let mut _0: ();                      // return place in scope 0 at $DIR/issue_76432.rs:6:44: 6:44
+      let _2: &[T];                        // in scope 0 at $DIR/issue_76432.rs:7:9: 7:10
+      let mut _3: &[T; 3];                 // in scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+      let _4: &[T; 3];                     // in scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+      let _5: [T; 3];                      // in scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+      let mut _6: T;                       // in scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+      let mut _7: T;                       // in scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+      let mut _8: T;                       // in scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+      let _9: [*const T; 3];               // in scope 0 at $DIR/issue_76432.rs:8:5: 11:6
+      let mut _10: usize;                  // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+      let mut _11: usize;                  // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+      let mut _12: bool;                   // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+      let mut _16: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:38: 9:52
+      let mut _17: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:38: 9:52
+      let mut _18: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:54: 9:68
+      let mut _19: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:54: 9:68
+      let mut _20: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:70: 9:84
+      let mut _21: *const T;               // in scope 0 at $DIR/issue_76432.rs:9:70: 9:84
+      let mut _22: !;                      // in scope 0 at $SRC_DIR/std/src/macros.rs:LL:COL
+      scope 1 {
+          debug v => _2;                   // in scope 1 at $DIR/issue_76432.rs:7:9: 7:10
+          let _13: &T;                     // in scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+          let _14: &T;                     // in scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+          let _15: &T;                     // in scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+          scope 2 {
+              debug v1 => _13;             // in scope 2 at $DIR/issue_76432.rs:9:10: 9:16
+              debug v2 => _14;             // in scope 2 at $DIR/issue_76432.rs:9:18: 9:24
+              debug v3 => _15;             // in scope 2 at $DIR/issue_76432.rs:9:26: 9:32
+          }
+      }
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/issue_76432.rs:7:9: 7:10
+          StorageLive(_3);                 // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          StorageLive(_4);                 // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          StorageLive(_5);                 // scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+          StorageLive(_6);                 // scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+          _6 = _1;                         // scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+          StorageLive(_7);                 // scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+          _7 = _1;                         // scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+          StorageLive(_8);                 // scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+          _8 = _1;                         // scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+          _5 = [move _6, move _7, move _8]; // scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+          StorageDead(_8);                 // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+          StorageDead(_7);                 // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+          StorageDead(_6);                 // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+          _4 = &_5;                        // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          _3 = _4;                         // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          _2 = move _3 as &[T] (Pointer(Unsize)); // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          StorageDead(_3);                 // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+          StorageDead(_4);                 // scope 0 at $DIR/issue_76432.rs:7:29: 7:30
+          StorageLive(_9);                 // scope 1 at $DIR/issue_76432.rs:8:5: 11:6
+          _10 = Len((*_2));                // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+          _11 = const 3_usize;             // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+-         _12 = Eq(move _10, const 3_usize); // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+-         switchInt(move _12) -> [false: bb1, otherwise: bb2]; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
++         nop;                             // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
++         switchInt(move _10) -> [3_usize: bb2, otherwise: bb1]; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+      }
+  
+      bb1: {
+          StorageLive(_22);                // scope 1 at $SRC_DIR/std/src/macros.rs:LL:COL
+          begin_panic::<&str>(const "internal error: entered unreachable code"); // scope 1 at $SRC_DIR/std/src/macros.rs:LL:COL
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/std/src/macros.rs:LL:COL
+                                           // + literal: Const { ty: fn(&str) -> ! {std::rt::begin_panic::<&str>}, val: Value(Scalar(<ZST>)) }
+                                           // ty::Const
+                                           // + ty: &str
+                                           // + val: Value(Slice { data: Allocation { bytes: [105, 110, 116, 101, 114, 110, 97, 108, 32, 101, 114, 114, 111, 114, 58, 32, 101, 110, 116, 101, 114, 101, 100, 32, 117, 110, 114, 101, 97, 99, 104, 97, 98, 108, 101, 32, 99, 111, 100, 101], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1099511627775], len: Size { raw: 40 } }, size: Size { raw: 40 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 40 })
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [105, 110, 116, 101, 114, 110, 97, 108, 32, 101, 114, 114, 111, 114, 58, 32, 101, 110, 116, 101, 114, 101, 100, 32, 117, 110, 114, 101, 97, 99, 104, 97, 98, 108, 101, 32, 99, 111, 100, 101], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1099511627775], len: Size { raw: 40 } }, size: Size { raw: 40 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 40 }) }
+      }
+  
+      bb2: {
+          StorageLive(_13);                // scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+          _13 = &(*_2)[0 of 3];            // scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+          StorageLive(_14);                // scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+          _14 = &(*_2)[1 of 3];            // scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+          StorageLive(_15);                // scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+          _15 = &(*_2)[2 of 3];            // scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+          StorageLive(_16);                // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+          StorageLive(_17);                // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+          _17 = &raw const (*_13);         // scope 2 at $DIR/issue_76432.rs:9:38: 9:40
+          _16 = _17;                       // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+          StorageLive(_18);                // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+          StorageLive(_19);                // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+          _19 = &raw const (*_14);         // scope 2 at $DIR/issue_76432.rs:9:54: 9:56
+          _18 = _19;                       // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+          StorageLive(_20);                // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+          StorageLive(_21);                // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+          _21 = &raw const (*_15);         // scope 2 at $DIR/issue_76432.rs:9:70: 9:72
+          _20 = _21;                       // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+          _9 = [move _16, move _18, move _20]; // scope 2 at $DIR/issue_76432.rs:9:37: 9:85
+          StorageDead(_21);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_20);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_19);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_18);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_17);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_16);                // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_15);                // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_14);                // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_13);                // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+          StorageDead(_9);                 // scope 1 at $DIR/issue_76432.rs:11:6: 11:7
+          _0 = const ();                   // scope 0 at $DIR/issue_76432.rs:6:44: 12:2
+          StorageDead(_5);                 // scope 0 at $DIR/issue_76432.rs:12:1: 12:2
+          StorageDead(_2);                 // scope 0 at $DIR/issue_76432.rs:12:1: 12:2
+          return;                          // scope 0 at $DIR/issue_76432.rs:12:2: 12:2
+      }
+  }
+