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-rw-r--r--src/test/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff7
-rw-r--r--src/test/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff7
-rw-r--r--src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff12
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound.InstCombine.diff66
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff68
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound.SimplifyLocals.diff73
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound_mut.InstCombine.diff79
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff81
-rw-r--r--src/test/mir-opt/lower_array_len.array_bound_mut.SimplifyLocals.diff96
-rw-r--r--src/test/mir-opt/lower_array_len.array_len.InstCombine.diff27
-rw-r--r--src/test/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff30
-rw-r--r--src/test/mir-opt/lower_array_len.array_len.SimplifyLocals.diff25
-rw-r--r--src/test/mir-opt/lower_array_len.array_len_by_value.InstCombine.diff26
-rw-r--r--src/test/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff30
-rw-r--r--src/test/mir-opt/lower_array_len.array_len_by_value.SimplifyLocals.diff25
-rw-r--r--src/test/mir-opt/lower_array_len.rs47
16 files changed, 690 insertions, 9 deletions
diff --git a/src/test/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff b/src/test/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
index f305d602bbd..dfb5b98d5c9 100644
--- a/src/test/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
+++ b/src/test/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
@@ -12,6 +12,7 @@
       let mut _7: usize;                   // in scope 0 at $DIR/slice_len.rs:5:5: 5:33
       let mut _8: bool;                    // in scope 0 at $DIR/slice_len.rs:5:5: 5:33
       let mut _9: &[u32; 3];               // in scope 0 at $DIR/slice_len.rs:5:6: 5:19
+      let mut _10: &[u32; 3];              // in scope 0 at $DIR/slice_len.rs:5:6: 5:19
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
@@ -27,14 +28,16 @@
                                            // + literal: Const { ty: &[u32; 3], val: Unevaluated(Unevaluated { def: WithOptConstParam { did: DefId(0:3 ~ slice_len[6547]::main), const_param_did: None }, substs_: Some([]), promoted: Some(promoted[0]) }) }
           _4 = _9;                         // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           _3 = _4;                         // scope 0 at $DIR/slice_len.rs:5:6: 5:19
+          StorageLive(_10);                // scope 0 at $DIR/slice_len.rs:5:6: 5:19
+          _10 = _3;                        // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           _2 = move _3 as &[u32] (Pointer(Unsize)); // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           StorageDead(_3);                 // scope 0 at $DIR/slice_len.rs:5:18: 5:19
           StorageLive(_6);                 // scope 0 at $DIR/slice_len.rs:5:31: 5:32
           _6 = const 1_usize;              // scope 0 at $DIR/slice_len.rs:5:31: 5:32
--         _7 = Len((*_2));                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
+          _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:5:5: 5:33
+          StorageDead(_10);                // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 -         _8 = Lt(_6, _7);                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:5:5: 5:33
-+         _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 +         _8 = const true;                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> bb1; // scope 0 at $DIR/slice_len.rs:5:5: 5:33
       }
diff --git a/src/test/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff b/src/test/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
index f305d602bbd..dfb5b98d5c9 100644
--- a/src/test/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
+++ b/src/test/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
@@ -12,6 +12,7 @@
       let mut _7: usize;                   // in scope 0 at $DIR/slice_len.rs:5:5: 5:33
       let mut _8: bool;                    // in scope 0 at $DIR/slice_len.rs:5:5: 5:33
       let mut _9: &[u32; 3];               // in scope 0 at $DIR/slice_len.rs:5:6: 5:19
+      let mut _10: &[u32; 3];              // in scope 0 at $DIR/slice_len.rs:5:6: 5:19
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
@@ -27,14 +28,16 @@
                                            // + literal: Const { ty: &[u32; 3], val: Unevaluated(Unevaluated { def: WithOptConstParam { did: DefId(0:3 ~ slice_len[6547]::main), const_param_did: None }, substs_: Some([]), promoted: Some(promoted[0]) }) }
           _4 = _9;                         // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           _3 = _4;                         // scope 0 at $DIR/slice_len.rs:5:6: 5:19
+          StorageLive(_10);                // scope 0 at $DIR/slice_len.rs:5:6: 5:19
+          _10 = _3;                        // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           _2 = move _3 as &[u32] (Pointer(Unsize)); // scope 0 at $DIR/slice_len.rs:5:6: 5:19
           StorageDead(_3);                 // scope 0 at $DIR/slice_len.rs:5:18: 5:19
           StorageLive(_6);                 // scope 0 at $DIR/slice_len.rs:5:31: 5:32
           _6 = const 1_usize;              // scope 0 at $DIR/slice_len.rs:5:31: 5:32
--         _7 = Len((*_2));                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
+          _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:5:5: 5:33
+          StorageDead(_10);                // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 -         _8 = Lt(_6, _7);                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:5:5: 5:33
-+         _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 +         _8 = const true;                 // scope 0 at $DIR/slice_len.rs:5:5: 5:33
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> bb1; // scope 0 at $DIR/slice_len.rs:5:5: 5:33
       }
diff --git a/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
index 96adadbe030..97c549dc9c8 100644
--- a/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
+++ b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
@@ -22,6 +22,7 @@
       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/core/src/panic.rs:LL:COL
+      let mut _23: &[T; 3];                // in scope 0 at $DIR/issue_76432.rs:7:19: 7:29
       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
@@ -51,16 +52,17 @@
           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
+          StorageLive(_23);                // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+          _23 = _3;                        // 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
+          _10 = const 3_usize;             // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+          StorageDead(_23);                // 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
+          _12 = const true;                // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+          goto -> bb2;                     // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
       }
   
       bb1: {
diff --git a/src/test/mir-opt/lower_array_len.array_bound.InstCombine.diff b/src/test/mir-opt/lower_array_len.array_bound.InstCombine.diff
new file mode 100644
index 00000000000..c7226573d75
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound.InstCombine.diff
@@ -0,0 +1,66 @@
+- // MIR for `array_bound` before InstCombine
++ // MIR for `array_bound` after InstCombine
+  
+  fn array_bound(_1: usize, _2: &[u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:6:36: 6:41
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:6:50: 6:55
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:6:70: 6:72
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+      let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      let mut _11: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         _7 = _2;                         // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          _11 = _7;                        // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:20: 7:21
+-         _5 = Len((*_11));                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          switchInt(move _3) -> [false: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      }
+  
+      bb1: {
+          StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+          _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+-         _9 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++         _9 = const N;                    // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb2; // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      }
+  
+      bb2: {
+          _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:9:5: 9:6
+          goto -> bb4;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb3: {
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:10:9: 10:11
+          goto -> bb4;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb4: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:11:5: 11:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:12:2: 12:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff b/src/test/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..d6c1c92cd91
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff
@@ -0,0 +1,68 @@
+- // MIR for `array_bound` before NormalizeArrayLen
++ // MIR for `array_bound` after NormalizeArrayLen
+  
+  fn array_bound(_1: usize, _2: &[u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:6:36: 6:41
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:6:50: 6:55
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:6:70: 6:72
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+      let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++     let mut _11: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         _11 = _7;                        // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:20: 7:21
+-         _5 = Len((*_6));                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         _5 = Len((*_11));                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++         StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+          goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+      }
+  
+      bb1: {
+          StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          switchInt(move _3) -> [false: bb4, otherwise: bb2]; // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      }
+  
+      bb2: {
+          StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+          _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+          _9 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb3; // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      }
+  
+      bb3: {
+          _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+          StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:9:5: 9:6
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb4: {
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:10:9: 10:11
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb5: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:11:5: 11:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:12:2: 12:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_bound.SimplifyLocals.diff b/src/test/mir-opt/lower_array_len.array_bound.SimplifyLocals.diff
new file mode 100644
index 00000000000..5cf3312cd64
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound.SimplifyLocals.diff
@@ -0,0 +1,73 @@
+- // MIR for `array_bound` before SimplifyLocals
++ // MIR for `array_bound` after SimplifyLocals
+  
+  fn array_bound(_1: usize, _2: &[u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:6:36: 6:41
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:6:50: 6:55
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:6:70: 6:72
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-     let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-     let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-     let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+-     let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+-     let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+-     let mut _11: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
++     let _6: usize;                       // in scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
++     let mut _7: usize;                   // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++     let mut _8: bool;                    // in scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:7:8: 7:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         _7 = _2;                         // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         _11 = _7;                        // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:7:20: 7:21
+          _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:7:16: 7:27
+-         StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:7:26: 7:27
+          switchInt(move _3) -> [false: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len.rs:7:8: 7:27
+      }
+  
+      bb1: {
+-         StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+-         _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
+-         _9 = const N;                    // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+-         _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+-         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb2; // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++         StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
++         _6 = _1;                         // scope 0 at $DIR/lower_array_len.rs:8:15: 8:20
++         _7 = const N;                    // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++         _8 = Lt(_6, _7);                 // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb2; // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+      }
+  
+      bb2: {
+-         _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
+-         StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:9:5: 9:6
++         _0 = (*_2)[_6];                  // scope 0 at $DIR/lower_array_len.rs:8:9: 8:21
++         StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:9:5: 9:6
+          goto -> bb4;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb3: {
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:10:9: 10:11
+          goto -> bb4;                     // scope 0 at $DIR/lower_array_len.rs:7:5: 11:6
+      }
+  
+      bb4: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:11:5: 11:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:12:2: 12:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_bound_mut.InstCombine.diff b/src/test/mir-opt/lower_array_len.array_bound_mut.InstCombine.diff
new file mode 100644
index 00000000000..5622d484532
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound_mut.InstCombine.diff
@@ -0,0 +1,79 @@
+- // MIR for `array_bound_mut` before InstCombine
++ // MIR for `array_bound_mut` after InstCombine
+  
+  fn array_bound_mut(_1: usize, _2: &mut [u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:17:40: 17:45
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:17:54: 17:59
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:17:78: 17:80
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+      let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      let _11: usize;                      // in scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+      let mut _12: usize;                  // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      let mut _13: bool;                   // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      let mut _14: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageLive(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          _14 = _7;                        // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:20: 18:21
+-         _5 = Len((*_14));                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++         _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageDead(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          switchInt(move _3) -> [false: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      }
+  
+      bb1: {
+          StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+          _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+-         _9 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++         _9 = const N;                    // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb2; // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      }
+  
+      bb2: {
+          _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:20:5: 20:6
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb3: {
+          StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+          _11 = const 0_usize;             // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+-         _12 = Len((*_2));                // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++         _12 = const N;                   // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+          _13 = Lt(_11, _12);              // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+          assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, _11) -> bb4; // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      }
+  
+      bb4: {
+          (*_2)[_11] = const 42_u8;        // scope 0 at $DIR/lower_array_len.rs:21:9: 21:22
+          StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:21:22: 21:23
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:23:9: 23:11
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb5: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:24:5: 24:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:25:2: 25:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff b/src/test/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..11fc20aa693
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff
@@ -0,0 +1,81 @@
+- // MIR for `array_bound_mut` before NormalizeArrayLen
++ // MIR for `array_bound_mut` after NormalizeArrayLen
+  
+  fn array_bound_mut(_1: usize, _2: &mut [u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:17:40: 17:45
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:17:54: 17:59
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:17:78: 17:80
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+      let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      let _11: usize;                      // in scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+      let mut _12: usize;                  // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      let mut _13: bool;                   // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++     let mut _14: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++         StorageLive(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++         _14 = _7;                        // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:20: 18:21
+-         _5 = Len((*_6));                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++         _5 = Len((*_14));                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++         StorageDead(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+          goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+      }
+  
+      bb1: {
+          StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          switchInt(move _3) -> [false: bb4, otherwise: bb2]; // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      }
+  
+      bb2: {
+          StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+          _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+          _9 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb3; // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      }
+  
+      bb3: {
+          _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+          StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:20:5: 20:6
+          goto -> bb6;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb4: {
+          StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+          _11 = const 0_usize;             // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+          _12 = Len((*_2));                // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+          _13 = Lt(_11, _12);              // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+          assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, _11) -> bb5; // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      }
+  
+      bb5: {
+          (*_2)[_11] = const 42_u8;        // scope 0 at $DIR/lower_array_len.rs:21:9: 21:22
+          StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:21:22: 21:23
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:23:9: 23:11
+          goto -> bb6;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb6: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:24:5: 24:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:25:2: 25:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_bound_mut.SimplifyLocals.diff b/src/test/mir-opt/lower_array_len.array_bound_mut.SimplifyLocals.diff
new file mode 100644
index 00000000000..f72aee0e502
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_bound_mut.SimplifyLocals.diff
@@ -0,0 +1,96 @@
+- // MIR for `array_bound_mut` before SimplifyLocals
++ // MIR for `array_bound_mut` after SimplifyLocals
+  
+  fn array_bound_mut(_1: usize, _2: &mut [u8; N]) -> u8 {
+      debug index => _1;                   // in scope 0 at $DIR/lower_array_len.rs:17:40: 17:45
+      debug slice => _2;                   // in scope 0 at $DIR/lower_array_len.rs:17:54: 17:59
+      let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len.rs:17:78: 17:80
+      let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+      let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-     let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-     let mut _7: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-     let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+-     let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+-     let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+-     let _11: usize;                      // in scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+-     let mut _12: usize;                  // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+-     let mut _13: bool;                   // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+-     let mut _14: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
++     let _6: usize;                       // in scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
++     let mut _7: usize;                   // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++     let mut _8: bool;                    // in scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++     let _9: usize;                       // in scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
++     let mut _10: usize;                  // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++     let mut _11: bool;                   // in scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          _4 = _1;                         // scope 0 at $DIR/lower_array_len.rs:18:8: 18:13
+          StorageLive(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageLive(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         _14 = _7;                        // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:18:20: 18:21
+          _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageDead(_14);                // scope 0 at $DIR/lower_array_len.rs:18:16: 18:27
+-         StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+          StorageDead(_5);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:18:26: 18:27
+          switchInt(move _3) -> [false: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len.rs:18:8: 18:27
+      }
+  
+      bb1: {
+-         StorageLive(_8);                 // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+-         _8 = _1;                         // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
+-         _9 = const N;                    // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+-         _10 = Lt(_8, _9);                // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+-         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> bb2; // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++         StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
++         _6 = _1;                         // scope 0 at $DIR/lower_array_len.rs:19:15: 19:20
++         _7 = const N;                    // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++         _8 = Lt(_6, _7);                 // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb2; // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+      }
+  
+      bb2: {
+-         _0 = (*_2)[_8];                  // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
+-         StorageDead(_8);                 // scope 0 at $DIR/lower_array_len.rs:20:5: 20:6
++         _0 = (*_2)[_6];                  // scope 0 at $DIR/lower_array_len.rs:19:9: 19:21
++         StorageDead(_6);                 // scope 0 at $DIR/lower_array_len.rs:20:5: 20:6
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb3: {
+-         StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+-         _11 = const 0_usize;             // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
+-         _12 = const N;                   // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+-         _13 = Lt(const 0_usize, _12);    // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+-         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, const 0_usize) -> bb4; // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++         StorageLive(_9);                 // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
++         _9 = const 0_usize;              // scope 0 at $DIR/lower_array_len.rs:21:15: 21:16
++         _10 = const N;                   // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++         _11 = Lt(const 0_usize, _10);    // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
++         assert(move _11, "index out of bounds: the length is {} but the index is {}", move _10, const 0_usize) -> bb4; // scope 0 at $DIR/lower_array_len.rs:21:9: 21:17
+      }
+  
+      bb4: {
+-         (*_2)[_11] = const 42_u8;        // scope 0 at $DIR/lower_array_len.rs:21:9: 21:22
+-         StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:21:22: 21:23
++         (*_2)[_9] = const 42_u8;         // scope 0 at $DIR/lower_array_len.rs:21:9: 21:22
++         StorageDead(_9);                 // scope 0 at $DIR/lower_array_len.rs:21:22: 21:23
+          _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len.rs:23:9: 23:11
+          goto -> bb5;                     // scope 0 at $DIR/lower_array_len.rs:18:5: 24:6
+      }
+  
+      bb5: {
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:24:5: 24:6
+          return;                          // scope 0 at $DIR/lower_array_len.rs:25:2: 25:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len.InstCombine.diff b/src/test/mir-opt/lower_array_len.array_len.InstCombine.diff
new file mode 100644
index 00000000000..a818de39bcc
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len.InstCombine.diff
@@ -0,0 +1,27 @@
+- // MIR for `array_len` before InstCombine
++ // MIR for `array_len` after InstCombine
+  
+  fn array_len(_1: &[u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:30:34: 30:37
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:30:52: 30:57
+      let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+      let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         _3 = &(*_1);                     // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         _3 = _1;                         // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:7: 31:8
+-         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:13: 31:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:32:2: 32:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff b/src/test/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..892fdda818e
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
@@ -0,0 +1,30 @@
+- // MIR for `array_len` before NormalizeArrayLen
++ // MIR for `array_len` after NormalizeArrayLen
+  
+  fn array_len(_1: &[u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:30:34: 30:37
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:30:52: 30:57
+      let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          _3 = &(*_1);                     // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:7: 31:8
+-         _0 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
++         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+          goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+      }
+  
+      bb1: {
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:13: 31:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:32:2: 32:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len.SimplifyLocals.diff b/src/test/mir-opt/lower_array_len.array_len.SimplifyLocals.diff
new file mode 100644
index 00000000000..20e2685aba5
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len.SimplifyLocals.diff
@@ -0,0 +1,25 @@
+- // MIR for `array_len` before SimplifyLocals
++ // MIR for `array_len` after SimplifyLocals
+  
+  fn array_len(_1: &[u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:30:34: 30:37
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:30:52: 30:57
+-     let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-     let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+  
+      bb0: {
+-         StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         _3 = _1;                         // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:31:7: 31:8
+          _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:31:5: 31:14
+-         StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:31:13: 31:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:32:2: 32:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len_by_value.InstCombine.diff b/src/test/mir-opt/lower_array_len.array_len_by_value.InstCombine.diff
new file mode 100644
index 00000000000..ce12531e84b
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len_by_value.InstCombine.diff
@@ -0,0 +1,26 @@
+- // MIR for `array_len_by_value` before InstCombine
++ // MIR for `array_len_by_value` after InstCombine
+  
+  fn array_len_by_value(_1: [u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:37:43: 37:46
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:37:60: 37:65
+      let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+      let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          _3 = &_1;                        // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:7: 38:8
+-         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++         _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:13: 38:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:39:2: 39:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff b/src/test/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..201fffbf0d4
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff
@@ -0,0 +1,30 @@
+- // MIR for `array_len_by_value` before NormalizeArrayLen
++ // MIR for `array_len_by_value` after NormalizeArrayLen
+  
+  fn array_len_by_value(_1: [u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:37:43: 37:46
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:37:60: 37:65
+      let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          _3 = &_1;                        // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:7: 38:8
+-         _0 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
++         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+          goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+      }
+  
+      bb1: {
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:13: 38:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:39:2: 39:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.array_len_by_value.SimplifyLocals.diff b/src/test/mir-opt/lower_array_len.array_len_by_value.SimplifyLocals.diff
new file mode 100644
index 00000000000..7e7b708145f
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.array_len_by_value.SimplifyLocals.diff
@@ -0,0 +1,25 @@
+- // MIR for `array_len_by_value` before SimplifyLocals
++ // MIR for `array_len_by_value` after SimplifyLocals
+  
+  fn array_len_by_value(_1: [u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:37:43: 37:46
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:37:60: 37:65
+-     let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-     let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+  
+      bb0: {
+-         StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         _3 = &_1;                        // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:38:7: 38:8
+          _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:38:5: 38:14
+-         StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:38:13: 38:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:39:2: 39:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/lower_array_len.rs b/src/test/mir-opt/lower_array_len.rs
new file mode 100644
index 00000000000..fc12ee75fcf
--- /dev/null
+++ b/src/test/mir-opt/lower_array_len.rs
@@ -0,0 +1,47 @@
+// compile-flags: -Z mir-opt-level=4
+
+// EMIT_MIR lower_array_len.array_bound.NormalizeArrayLen.diff
+// EMIT_MIR lower_array_len.array_bound.SimplifyLocals.diff
+// EMIT_MIR lower_array_len.array_bound.InstCombine.diff
+pub fn array_bound<const N: usize>(index: usize, slice: &[u8; N]) -> u8 {
+    if index < slice.len() {
+        slice[index]
+    } else {
+        42
+    }
+}
+
+// EMIT_MIR lower_array_len.array_bound_mut.NormalizeArrayLen.diff
+// EMIT_MIR lower_array_len.array_bound_mut.SimplifyLocals.diff
+// EMIT_MIR lower_array_len.array_bound_mut.InstCombine.diff
+pub fn array_bound_mut<const N: usize>(index: usize, slice: &mut [u8; N]) -> u8 {
+    if index < slice.len() {
+        slice[index]
+    } else {
+        slice[0] = 42;
+
+        42
+    }
+}
+
+// EMIT_MIR lower_array_len.array_len.NormalizeArrayLen.diff
+// EMIT_MIR lower_array_len.array_len.SimplifyLocals.diff
+// EMIT_MIR lower_array_len.array_len.InstCombine.diff
+pub fn array_len<const N: usize>(arr: &[u8; N]) -> usize {
+    arr.len()
+}
+
+// EMIT_MIR lower_array_len.array_len_by_value.NormalizeArrayLen.diff
+// EMIT_MIR lower_array_len.array_len_by_value.SimplifyLocals.diff
+// EMIT_MIR lower_array_len.array_len_by_value.InstCombine.diff
+pub fn array_len_by_value<const N: usize>(arr: [u8; N]) -> usize {
+    arr.len()
+}
+
+fn main() {
+    let _ = array_bound(3, &[0, 1, 2, 3]);
+    let mut tmp = [0, 1, 2, 3, 4];
+    let _ = array_bound_mut(3, &mut [0, 1, 2, 3]);
+    let _ = array_len(&[0]);
+    let _ = array_len_by_value([0, 2]);
+}