lower ExprKind::Use, LogicalOp::Or and UnOp::Not

Co-authored-by: Abdulaziz Ghuloum <aghuloum@gmail.com>

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -64,6 +64,43 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
                 rhs_then_block.unit()
             }
+            ExprKind::LogicalOp { op: LogicalOp::Or, lhs, rhs } => {
+                let local_scope = this.local_scope();
+                let (lhs_success_block, failure_block) =
+                    this.in_if_then_scope(local_scope, expr_span, |this| {
+                        this.then_else_break(
+                            block,
+                            &this.thir[lhs],
+                            temp_scope_override,
+                            local_scope,
+                            variable_source_info,
+                        )
+                    });
+                let rhs_success_block = unpack!(this.then_else_break(
+                    failure_block,
+                    &this.thir[rhs],
+                    temp_scope_override,
+                    break_scope,
+                    variable_source_info,
+                ));
+                this.cfg.goto(lhs_success_block, variable_source_info, rhs_success_block);
+                rhs_success_block.unit()
+            }
+            ExprKind::Unary { op: UnOp::Not, arg } => {
+                let local_scope = this.local_scope();
+                let (success_block, failure_block) =
+                    this.in_if_then_scope(local_scope, expr_span, |this| {
+                        this.then_else_break(
+                            block,
+                            &this.thir[arg],
+                            temp_scope_override,
+                            local_scope,
+                            variable_source_info,
+                        )
+                    });
+                this.break_for_else(success_block, break_scope, variable_source_info);
+                failure_block.unit()
+            }
             ExprKind::Scope { region_scope, lint_level, value } => {
                 let region_scope = (region_scope, this.source_info(expr_span));
                 this.in_scope(region_scope, lint_level, |this| {
@@ -76,6 +113,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     )
                 })
             }
+            ExprKind::Use { source } => this.then_else_break(
+                block,
+                &this.thir[source],
+                temp_scope_override,
+                break_scope,
+                variable_source_info,
+            ),
             ExprKind::Let { expr, ref pat } => this.lower_let_expr(
                 block,
                 &this.thir[expr],

tests/mir-opt/bool_compare.opt1.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Ne(move _3, const true);
 +         _2 = Not(move _3);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/bool_compare.opt2.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Ne(const true, move _3);
 +         _2 = Not(move _3);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/bool_compare.opt3.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Eq(move _3, const false);
 +         _2 = Not(move _3);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/bool_compare.opt4.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Eq(const false, move _3);
 +         _2 = Not(move _3);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/building/logical_or_in_conditional.test_complex.built.after.mir

@@ -7,22 +7,19 @@ fn test_complex() -> () {
     let mut _3: isize;
     let mut _4: bool;
     let mut _5: bool;
-    let mut _6: bool;
+    let mut _6: u8;
-    let mut _7: bool;
+    let mut _7: Droppy;
-    let mut _8: u8;
+    let mut _8: bool;
-    let mut _9: Droppy;
+    let mut _9: u8;
-    let mut _10: bool;
+    let mut _10: Droppy;
-    let mut _11: u8;
+    let mut _11: bool;
-    let mut _12: Droppy;
+    let mut _12: E;
-    let mut _13: bool;
+    let mut _13: isize;
-    let mut _14: bool;
-    let mut _15: E;
-    let mut _16: isize;
 
     bb0: {
         StorageLive(_1);
         StorageLive(_2);
-        _2 = E::f() -> [return: bb1, unwind: bb27];
+        _2 = E::f() -> [return: bb1, unwind: bb31];
     }
 
     bb1: {
@@ -36,145 +33,154 @@ fn test_complex() -> () {
     }
 
     bb3: {
-        goto -> bb16;
+        goto -> bb19;
     }
 
     bb4: {
         StorageLive(_4);
-        StorageLive(_5);
+        _4 = always_true() -> [return: bb5, unwind: bb31];
-        StorageLive(_6);
-        _6 = always_true() -> [return: bb11, unwind: bb27];
     }
 
     bb5: {
-        _4 = const true;
+        switchInt(move _4) -> [0: bb7, otherwise: bb6];
-        goto -> bb7;
     }
 
     bb6: {
-        StorageLive(_10);
+        StorageLive(_5);
-        StorageLive(_11);
+        StorageLive(_6);
-        StorageLive(_12);
+        StorageLive(_7);
-        _12 = Droppy(const 1_u8);
+        _7 = Droppy(const 0_u8);
-        _11 = (_12.0: u8);
+        _6 = (_7.0: u8);
-        _10 = Gt(move _11, const 1_u8);
+        _5 = Gt(move _6, const 0_u8);
-        drop(_12) -> [return: bb13, unwind: bb27];
+        switchInt(move _5) -> [0: bb9, otherwise: bb8];
     }
 
     bb7: {
-        StorageDead(_10);
+        goto -> bb13;
-        StorageDead(_5);
-        switchInt(move _4) -> [0: bb15, otherwise: bb14];
     }
 
     bb8: {
-        _5 = const false;
+        drop(_7) -> [return: bb10, unwind: bb31];
-        goto -> bb10;
     }
 
     bb9: {
-        StorageLive(_7);
+        goto -> bb11;
-        StorageLive(_8);
-        StorageLive(_9);
-        _9 = Droppy(const 0_u8);
-        _8 = (_9.0: u8);
-        _7 = Gt(move _8, const 0_u8);
-        drop(_9) -> [return: bb12, unwind: bb27];
     }
 
     bb10: {
         StorageDead(_7);
         StorageDead(_6);
-        switchInt(move _5) -> [0: bb6, otherwise: bb5];
-    }
-
-    bb11: {
-        switchInt(move _6) -> [0: bb8, otherwise: bb9];
-    }
-
-    bb12: {
-        StorageDead(_9);
-        StorageDead(_8);
-        _5 = move _7;
-        goto -> bb10;
-    }
-
-    bb13: {
-        StorageDead(_12);
-        StorageDead(_11);
-        _4 = move _10;
-        goto -> bb7;
-    }
-
-    bb14: {
-        _1 = const ();
-        goto -> bb17;
-    }
-
-    bb15: {
         goto -> bb16;
     }
 
-    bb16: {
+    bb11: {
-        _1 = const ();
+        drop(_7) -> [return: bb12, unwind: bb31];
+    }
+
+    bb12: {
+        StorageDead(_7);
+        StorageDead(_6);
+        goto -> bb13;
+    }
+
+    bb13: {
+        StorageLive(_8);
+        StorageLive(_9);
+        StorageLive(_10);
+        _10 = Droppy(const 1_u8);
+        _9 = (_10.0: u8);
+        _8 = Gt(move _9, const 1_u8);
+        switchInt(move _8) -> [0: bb15, otherwise: bb14];
+    }
+
+    bb14: {
+        drop(_10) -> [return: bb16, unwind: bb31];
+    }
+
+    bb15: {
         goto -> bb17;
     }
 
+    bb16: {
+        StorageDead(_10);
+        StorageDead(_9);
+        _1 = const ();
+        goto -> bb20;
+    }
+
     bb17: {
-        StorageDead(_4);
+        drop(_10) -> [return: bb18, unwind: bb31];
-        StorageDead(_2);
-        StorageDead(_1);
-        StorageLive(_13);
-        StorageLive(_14);
-        _14 = always_true() -> [return: bb18, unwind: bb27];
     }
 
     bb18: {
-        _13 = Not(move _14);
+        StorageDead(_10);
-        StorageDead(_14);
+        StorageDead(_9);
-        switchInt(move _13) -> [0: bb20, otherwise: bb19];
+        goto -> bb19;
     }
 
     bb19: {
-        StorageLive(_15);
+        _1 = const ();
-        _15 = E::f() -> [return: bb21, unwind: bb27];
+        goto -> bb20;
     }
 
     bb20: {
-        goto -> bb25;
+        StorageDead(_8);
+        StorageDead(_5);
+        StorageDead(_4);
+        StorageDead(_2);
+        StorageDead(_1);
+        StorageLive(_11);
+        _11 = always_true() -> [return: bb21, unwind: bb31];
     }
 
     bb21: {
-        FakeRead(ForMatchedPlace(None), _15);
+        switchInt(move _11) -> [0: bb23, otherwise: bb22];
-        _16 = discriminant(_15);
-        switchInt(move _16) -> [1: bb23, otherwise: bb22];
     }
 
     bb22: {
-        goto -> bb25;
+        goto -> bb29;
     }
 
     bb23: {
-        falseEdge -> [real: bb24, imaginary: bb22];
+        goto -> bb24;
     }
 
     bb24: {
-        _0 = const ();
+        StorageLive(_12);
-        goto -> bb26;
+        _12 = E::f() -> [return: bb25, unwind: bb31];
     }
 
     bb25: {
-        _0 = const ();
+        FakeRead(ForMatchedPlace(None), _12);
-        goto -> bb26;
+        _13 = discriminant(_12);
+        switchInt(move _13) -> [1: bb27, otherwise: bb26];
     }
 
     bb26: {
-        StorageDead(_13);
+        goto -> bb29;
-        StorageDead(_15);
+    }
+
+    bb27: {
+        falseEdge -> [real: bb28, imaginary: bb26];
+    }
+
+    bb28: {
+        _0 = const ();
+        goto -> bb30;
+    }
+
+    bb29: {
+        _0 = const ();
+        goto -> bb30;
+    }
+
+    bb30: {
+        StorageDead(_11);
+        StorageDead(_12);
         return;
     }
 
-    bb27 (cleanup): {
+    bb31 (cleanup): {
         resume;
     }
 }

tests/mir-opt/building/logical_or_in_conditional.test_or.built.after.mir

@@ -3,78 +3,85 @@
 fn test_or() -> () {
     let mut _0: ();
     let mut _1: bool;
-    let mut _2: bool;
+    let mut _2: u8;
-    let mut _3: u8;
+    let mut _3: Droppy;
-    let mut _4: Droppy;
+    let mut _4: bool;
-    let mut _5: bool;
+    let mut _5: u8;
-    let mut _6: u8;
+    let mut _6: Droppy;
-    let mut _7: Droppy;
 
     bb0: {
         StorageLive(_1);
         StorageLive(_2);
         StorageLive(_3);
-        StorageLive(_4);
+        _3 = Droppy(const 0_u8);
-        _4 = Droppy(const 0_u8);
+        _2 = (_3.0: u8);
-        _3 = (_4.0: u8);
+        _1 = Gt(move _2, const 0_u8);
-        _2 = Gt(move _3, const 0_u8);
+        switchInt(move _1) -> [0: bb2, otherwise: bb1];
-        drop(_4) -> [return: bb4, unwind: bb10];
     }
 
     bb1: {
-        _1 = const true;
+        drop(_3) -> [return: bb3, unwind: bb12];
-        goto -> bb3;
     }
 
     bb2: {
-        StorageLive(_5);
+        goto -> bb4;
-        StorageLive(_6);
-        StorageLive(_7);
-        _7 = Droppy(const 1_u8);
-        _6 = (_7.0: u8);
-        _5 = Gt(move _6, const 1_u8);
-        drop(_7) -> [return: bb5, unwind: bb10];
     }
 
     bb3: {
-        StorageDead(_5);
-        StorageDead(_2);
-        switchInt(move _1) -> [0: bb7, otherwise: bb6];
-    }
-
-    bb4: {
-        StorageDead(_4);
         StorageDead(_3);
-        switchInt(move _2) -> [0: bb2, otherwise: bb1];
+        StorageDead(_2);
-    }
-
-    bb5: {
-        StorageDead(_7);
-        StorageDead(_6);
-        _1 = move _5;
-        goto -> bb3;
-    }
-
-    bb6: {
-        _0 = const ();
-        goto -> bb9;
-    }
-
-    bb7: {
         goto -> bb8;
     }
 
-    bb8: {
+    bb4: {
-        _0 = const ();
+        drop(_3) -> [return: bb5, unwind: bb12];
+    }
+
+    bb5: {
+        StorageDead(_3);
+        StorageDead(_2);
+        StorageLive(_4);
+        StorageLive(_5);
+        StorageLive(_6);
+        _6 = Droppy(const 1_u8);
+        _5 = (_6.0: u8);
+        _4 = Gt(move _5, const 1_u8);
+        switchInt(move _4) -> [0: bb7, otherwise: bb6];
+    }
+
+    bb6: {
+        drop(_6) -> [return: bb8, unwind: bb12];
+    }
+
+    bb7: {
         goto -> bb9;
     }
 
+    bb8: {
+        StorageDead(_6);
+        StorageDead(_5);
+        _0 = const ();
+        goto -> bb11;
+    }
+
     bb9: {
+        drop(_6) -> [return: bb10, unwind: bb12];
+    }
+
+    bb10: {
+        StorageDead(_6);
+        StorageDead(_5);
+        _0 = const ();
+        goto -> bb11;
+    }
+
+    bb11: {
+        StorageDead(_4);
         StorageDead(_1);
         return;
     }
 
-    bb10 (cleanup): {
+    bb12 (cleanup): {
         resume;
     }
 }

tests/mir-opt/const_goto_storage.match_nested_if.ConstGoto.diff

@@ -43,31 +43,33 @@
       }
   
       bb3: {
--         StorageDead(_6);
 -         switchInt(move _5) -> [0: bb5, otherwise: bb4];
 -     }
 - 
 -     bb4: {
+-         StorageDead(_6);
 -         _4 = const true;
 -         goto -> bb6;
 -     }
 - 
 -     bb5: {
+-         StorageDead(_6);
 -         _4 = const false;
 -         goto -> bb6;
 -     }
 - 
 -     bb6: {
--         StorageDead(_5);
 -         switchInt(move _4) -> [0: bb8, otherwise: bb7];
 -     }
 - 
 -     bb7: {
+-         StorageDead(_5);
 -         _3 = const true;
 -         goto -> bb9;
 -     }
 - 
 -     bb8: {
+-         StorageDead(_5);
 -         _3 = const false;
 -         goto -> bb9;
 -     }

tests/mir-opt/dataflow-const-prop/if.main.DataflowConstProp.diff

@@ -39,19 +39,20 @@
           StorageLive(_4);
 -         _4 = _1;
 -         _3 = Eq(move _4, const 1_i32);
+-         switchInt(move _3) -> [0: bb2, otherwise: bb1];
 +         _4 = const 1_i32;
 +         _3 = const true;
-          StorageDead(_4);
--         switchInt(move _3) -> [0: bb2, otherwise: bb1];
 +         switchInt(const true) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_4);
           _2 = const 2_i32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_4);
           _2 = const 3_i32;
           goto -> bb3;
       }
@@ -70,20 +71,21 @@
           StorageLive(_9);
 -         _9 = _1;
 -         _8 = Eq(move _9, const 1_i32);
+-         switchInt(move _8) -> [0: bb5, otherwise: bb4];
 +         _9 = const 1_i32;
 +         _8 = const true;
-          StorageDead(_9);
--         switchInt(move _8) -> [0: bb5, otherwise: bb4];
 +         switchInt(const true) -> [0: bb5, otherwise: bb4];
       }
   
       bb4: {
+          StorageDead(_9);
 -         _7 = _1;
 +         _7 = const 1_i32;
           goto -> bb6;
       }
   
       bb5: {
+          StorageDead(_9);
           StorageLive(_10);
           _10 = _1;
           _7 = Add(move _10, const 1_i32);

tests/mir-opt/equal_true.opt.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Eq(move _3, const true);
 +         _2 = move _3;
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_i32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_i32;
           goto -> bb3;
       }

tests/mir-opt/if_condition_int.dont_opt_floats.SimplifyComparisonIntegral.diff

@@ -12,16 +12,17 @@
           StorageLive(_3);
           _3 = _1;
           _2 = Eq(move _3, const -42f32);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_i32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_i32;
           goto -> bb3;
       }

tests/mir-opt/if_condition_int.opt_char.SimplifyComparisonIntegral.diff

@@ -12,21 +12,19 @@
           StorageLive(_3);
           _3 = _1;
 -         _2 = Eq(move _3, const 'x');
--         StorageDead(_3);
 -         switchInt(move _2) -> [0: bb2, otherwise: bb1];
 +         nop;
-+         nop;
 +         switchInt(move _3) -> [120: bb1, otherwise: bb2];
       }
   
       bb1: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/if_condition_int.opt_i8.SimplifyComparisonIntegral.diff

@@ -12,21 +12,19 @@
           StorageLive(_3);
           _3 = _1;
 -         _2 = Eq(move _3, const 42_i8);
--         StorageDead(_3);
 -         switchInt(move _2) -> [0: bb2, otherwise: bb1];
 +         nop;
-+         nop;
 +         switchInt(move _3) -> [42: bb1, otherwise: bb2];
       }
   
       bb1: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/if_condition_int.opt_multiple_ifs.SimplifyComparisonIntegral.diff

@@ -14,40 +14,36 @@
           StorageLive(_3);
           _3 = _1;
 -         _2 = Eq(move _3, const 42_u32);
--         StorageDead(_3);
 -         switchInt(move _2) -> [0: bb2, otherwise: bb1];
 +         nop;
-+         nop;
 +         switchInt(move _3) -> [42: bb1, otherwise: bb2];
       }
   
       bb1: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb6;
       }
   
       bb2: {
-+         StorageDead(_3);
+          StorageDead(_3);
           StorageLive(_4);
           StorageLive(_5);
           _5 = _1;
 -         _4 = Ne(move _5, const 21_u32);
--         StorageDead(_5);
 -         switchInt(move _4) -> [0: bb4, otherwise: bb3];
 +         nop;
-+         nop;
 +         switchInt(move _5) -> [21: bb4, otherwise: bb3];
       }
   
       bb3: {
-+         StorageDead(_5);
+          StorageDead(_5);
           _0 = const 1_u32;
           goto -> bb5;
       }
   
       bb4: {
-+         StorageDead(_5);
+          StorageDead(_5);
           _0 = const 2_u32;
           goto -> bb5;
       }

tests/mir-opt/if_condition_int.opt_negative.SimplifyComparisonIntegral.diff

@@ -12,21 +12,19 @@
           StorageLive(_3);
           _3 = _1;
 -         _2 = Eq(move _3, const -42_i32);
--         StorageDead(_3);
 -         switchInt(move _2) -> [0: bb2, otherwise: bb1];
 +         nop;
-+         nop;
 +         switchInt(move _3) -> [4294967254: bb1, otherwise: bb2];
       }
   
       bb1: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/if_condition_int.opt_u32.SimplifyComparisonIntegral.diff

@@ -12,21 +12,19 @@
           StorageLive(_3);
           _3 = _1;
 -         _2 = Eq(move _3, const 42_u32);
--         StorageDead(_3);
 -         switchInt(move _2) -> [0: bb2, otherwise: bb1];
 +         nop;
-+         nop;
 +         switchInt(move _3) -> [42: bb1, otherwise: bb2];
       }
   
       bb1: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
-+         StorageDead(_3);
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/inline/inline_diverging.g.Inline.panic-abort.diff

@@ -18,11 +18,11 @@
           StorageLive(_3);
           _3 = _1;
           _2 = Gt(move _3, const 0_i32);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           StorageLive(_4);
           _4 = _1;
           _0 = move _4 as u32 (IntToInt);
@@ -32,6 +32,7 @@
       }
   
       bb2: {
+          StorageDead(_3);
           StorageLive(_6);
 -         _6 = panic() -> unwind unreachable;
 +         StorageLive(_7);

tests/mir-opt/inline/inline_diverging.g.Inline.panic-unwind.diff

@@ -18,11 +18,11 @@
           StorageLive(_3);
           _3 = _1;
           _2 = Gt(move _3, const 0_i32);
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           StorageLive(_4);
           _4 = _1;
           _0 = move _4 as u32 (IntToInt);
@@ -32,6 +32,7 @@
       }
   
       bb2: {
+          StorageDead(_3);
           StorageLive(_6);
 -         _6 = panic() -> unwind continue;
 +         StorageLive(_7);

tests/mir-opt/issue_99325.main.built.after.mir

@@ -16,51 +16,49 @@ fn main() -> () {
     let _8: &&[u8];
     let _9: &&[u8; 4];
     let mut _10: bool;
-    let mut _11: bool;
+    let mut _11: &&[u8];
-    let mut _12: &&[u8];
+    let mut _12: &&[u8; 4];
-    let mut _13: &&[u8; 4];
+    let mut _13: !;
-    let mut _14: !;
+    let _15: !;
-    let _16: !;
+    let mut _16: core::panicking::AssertKind;
-    let mut _17: core::panicking::AssertKind;
+    let mut _17: &&[u8];
-    let mut _18: &&[u8];
+    let _18: &&[u8];
-    let _19: &&[u8];
+    let mut _19: &&[u8; 4];
-    let mut _20: &&[u8; 4];
+    let _20: &&[u8; 4];
-    let _21: &&[u8; 4];
+    let mut _21: std::option::Option<std::fmt::Arguments<'_>>;
-    let mut _22: std::option::Option<std::fmt::Arguments<'_>>;
+    let _22: ();
-    let _23: ();
+    let mut _23: (&&[u8], &&[u8; 4]);
-    let mut _24: (&&[u8], &&[u8; 4]);
+    let mut _24: &&[u8];
-    let mut _25: &&[u8];
+    let _25: &[u8];
-    let _26: &[u8];
+    let mut _26: &&[u8; 4];
-    let mut _27: &&[u8; 4];
+    let _27: &[u8; 4];
-    let _28: &[u8; 4];
+    let _28: &&[u8];
-    let _29: &&[u8];
+    let _29: &&[u8; 4];
-    let _30: &&[u8; 4];
+    let mut _30: bool;
-    let mut _31: bool;
+    let mut _31: &&[u8];
-    let mut _32: bool;
+    let mut _32: &&[u8; 4];
-    let mut _33: &&[u8];
+    let mut _33: !;
-    let mut _34: &&[u8; 4];
+    let _35: !;
-    let mut _35: !;
+    let mut _36: core::panicking::AssertKind;
-    let _37: !;
+    let mut _37: &&[u8];
-    let mut _38: core::panicking::AssertKind;
+    let _38: &&[u8];
-    let mut _39: &&[u8];
+    let mut _39: &&[u8; 4];
-    let _40: &&[u8];
+    let _40: &&[u8; 4];
-    let mut _41: &&[u8; 4];
+    let mut _41: std::option::Option<std::fmt::Arguments<'_>>;
-    let _42: &&[u8; 4];
-    let mut _43: std::option::Option<std::fmt::Arguments<'_>>;
     scope 1 {
         debug left_val => _8;
         debug right_val => _9;
-        let _15: core::panicking::AssertKind;
+        let _14: core::panicking::AssertKind;
         scope 2 {
-            debug kind => _15;
+            debug kind => _14;
         }
     }
     scope 3 {
-        debug left_val => _29;
+        debug left_val => _28;
-        debug right_val => _30;
+        debug right_val => _29;
-        let _36: core::panicking::AssertKind;
+        let _34: core::panicking::AssertKind;
         scope 4 {
-            debug kind => _36;
+            debug kind => _34;
         }
     }
 
@@ -69,7 +67,7 @@ fn main() -> () {
         StorageLive(_2);
         StorageLive(_3);
         StorageLive(_4);
-        _4 = function_with_bytes::<&*b"AAAA">() -> [return: bb1, unwind: bb19];
+        _4 = function_with_bytes::<&*b"AAAA">() -> [return: bb1, unwind: bb21];
     }
 
     bb1: {
@@ -90,179 +88,185 @@ fn main() -> () {
         _9 = (_2.1: &&[u8; 4]);
         StorageLive(_10);
         StorageLive(_11);
+        _11 = &(*_8);
         StorageLive(_12);
-        _12 = &(*_8);
+        _12 = &(*_9);
-        StorageLive(_13);
+        _10 = <&[u8] as PartialEq<&[u8; 4]>>::eq(move _11, move _12) -> [return: bb2, unwind: bb21];
-        _13 = &(*_9);
-        _11 = <&[u8] as PartialEq<&[u8; 4]>>::eq(move _12, move _13) -> [return: bb2, unwind: bb19];
     }
 
     bb2: {
-        StorageDead(_13);
-        StorageDead(_12);
-        _10 = Not(move _11);
-        StorageDead(_11);
         switchInt(move _10) -> [0: bb4, otherwise: bb3];
     }
 
     bb3: {
-        StorageLive(_15);
+        StorageDead(_12);
-        _15 = core::panicking::AssertKind::Eq;
+        StorageDead(_11);
-        FakeRead(ForLet(None), _15);
+        goto -> bb8;
-        StorageLive(_16);
-        StorageLive(_17);
-        _17 = move _15;
-        StorageLive(_18);
-        StorageLive(_19);
-        _19 = &(*_8);
-        _18 = &(*_19);
-        StorageLive(_20);
-        StorageLive(_21);
-        _21 = &(*_9);
-        _20 = &(*_21);
-        StorageLive(_22);
-        _22 = Option::<Arguments<'_>>::None;
-        _16 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _17, move _18, move _20, move _22) -> bb19;
     }
 
     bb4: {
-        goto -> bb7;
+        goto -> bb5;
     }
 
     bb5: {
-        StorageDead(_22);
+        StorageDead(_12);
-        StorageDead(_20);
+        StorageDead(_11);
-        StorageDead(_18);
+        StorageLive(_14);
-        StorageDead(_17);
+        _14 = core::panicking::AssertKind::Eq;
-        StorageDead(_21);
+        FakeRead(ForLet(None), _14);
-        StorageDead(_19);
+        StorageLive(_15);
-        StorageDead(_16);
+        StorageLive(_16);
-        StorageDead(_15);
+        _16 = move _14;
-        unreachable;
+        StorageLive(_17);
+        StorageLive(_18);
+        _18 = &(*_8);
+        _17 = &(*_18);
+        StorageLive(_19);
+        StorageLive(_20);
+        _20 = &(*_9);
+        _19 = &(*_20);
+        StorageLive(_21);
+        _21 = Option::<Arguments<'_>>::None;
+        _15 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _16, move _17, move _19, move _21) -> bb21;
     }
 
     bb6: {
-        goto -> bb8;
+        StorageDead(_21);
+        StorageDead(_19);
+        StorageDead(_17);
+        StorageDead(_16);
+        StorageDead(_20);
+        StorageDead(_18);
+        StorageDead(_15);
+        StorageDead(_14);
+        unreachable;
     }
 
     bb7: {
-        _1 = const ();
+        goto -> bb9;
-        goto -> bb8;
     }
 
     bb8: {
-        StorageDead(_10);
+        _1 = const ();
-        StorageDead(_9);
-        StorageDead(_8);
         goto -> bb9;
     }
 
     bb9: {
+        StorageDead(_10);
+        StorageDead(_9);
+        StorageDead(_8);
+        goto -> bb10;
+    }
+
+    bb10: {
         StorageDead(_7);
         StorageDead(_6);
         StorageDead(_4);
         StorageDead(_2);
         StorageDead(_1);
+        StorageLive(_22);
         StorageLive(_23);
         StorageLive(_24);
         StorageLive(_25);
-        StorageLive(_26);
+        _25 = function_with_bytes::<&*b"AAAA">() -> [return: bb11, unwind: bb21];
-        _26 = function_with_bytes::<&*b"AAAA">() -> [return: bb10, unwind: bb19];
-    }
-
-    bb10: {
-        _25 = &_26;
-        StorageLive(_27);
-        StorageLive(_28);
-        _28 = const b"AAAA";
-        _27 = &_28;
-        _24 = (move _25, move _27);
-        StorageDead(_27);
-        StorageDead(_25);
-        FakeRead(ForMatchedPlace(None), _24);
-        StorageLive(_29);
-        _29 = (_24.0: &&[u8]);
-        StorageLive(_30);
-        _30 = (_24.1: &&[u8; 4]);
-        StorageLive(_31);
-        StorageLive(_32);
-        StorageLive(_33);
-        _33 = &(*_29);
-        StorageLive(_34);
-        _34 = &(*_30);
-        _32 = <&[u8] as PartialEq<&[u8; 4]>>::eq(move _33, move _34) -> [return: bb11, unwind: bb19];
     }
 
     bb11: {
-        StorageDead(_34);
+        _24 = &_25;
-        StorageDead(_33);
+        StorageLive(_26);
-        _31 = Not(move _32);
+        StorageLive(_27);
-        StorageDead(_32);
+        _27 = const b"AAAA";
-        switchInt(move _31) -> [0: bb13, otherwise: bb12];
+        _26 = &_27;
+        _23 = (move _24, move _26);
+        StorageDead(_26);
+        StorageDead(_24);
+        FakeRead(ForMatchedPlace(None), _23);
+        StorageLive(_28);
+        _28 = (_23.0: &&[u8]);
+        StorageLive(_29);
+        _29 = (_23.1: &&[u8; 4]);
+        StorageLive(_30);
+        StorageLive(_31);
+        _31 = &(*_28);
+        StorageLive(_32);
+        _32 = &(*_29);
+        _30 = <&[u8] as PartialEq<&[u8; 4]>>::eq(move _31, move _32) -> [return: bb12, unwind: bb21];
     }
 
     bb12: {
+        switchInt(move _30) -> [0: bb14, otherwise: bb13];
+    }
+
+    bb13: {
+        StorageDead(_32);
+        StorageDead(_31);
+        goto -> bb18;
+    }
+
+    bb14: {
+        goto -> bb15;
+    }
+
+    bb15: {
+        StorageDead(_32);
+        StorageDead(_31);
+        StorageLive(_34);
+        _34 = core::panicking::AssertKind::Eq;
+        FakeRead(ForLet(None), _34);
+        StorageLive(_35);
         StorageLive(_36);
-        _36 = core::panicking::AssertKind::Eq;
+        _36 = move _34;
-        FakeRead(ForLet(None), _36);
         StorageLive(_37);
         StorageLive(_38);
-        _38 = move _36;
+        _38 = &(*_28);
+        _37 = &(*_38);
         StorageLive(_39);
         StorageLive(_40);
         _40 = &(*_29);
         _39 = &(*_40);
         StorageLive(_41);
-        StorageLive(_42);
+        _41 = Option::<Arguments<'_>>::None;
-        _42 = &(*_30);
+        _35 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _36, move _37, move _39, move _41) -> bb21;
-        _41 = &(*_42);
-        StorageLive(_43);
-        _43 = Option::<Arguments<'_>>::None;
-        _37 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _38, move _39, move _41, move _43) -> bb19;
-    }
-
-    bb13: {
-        goto -> bb16;
-    }
-
-    bb14: {
-        StorageDead(_43);
-        StorageDead(_41);
-        StorageDead(_39);
-        StorageDead(_38);
-        StorageDead(_42);
-        StorageDead(_40);
-        StorageDead(_37);
-        StorageDead(_36);
-        unreachable;
-    }
-
-    bb15: {
-        goto -> bb17;
     }
 
     bb16: {
-        _23 = const ();
+        StorageDead(_41);
-        goto -> bb17;
+        StorageDead(_39);
+        StorageDead(_37);
+        StorageDead(_36);
+        StorageDead(_40);
+        StorageDead(_38);
+        StorageDead(_35);
+        StorageDead(_34);
+        unreachable;
     }
 
     bb17: {
-        StorageDead(_31);
+        goto -> bb19;
-        StorageDead(_30);
-        StorageDead(_29);
-        goto -> bb18;
     }
 
     bb18: {
+        _22 = const ();
+        goto -> bb19;
+    }
+
+    bb19: {
+        StorageDead(_30);
+        StorageDead(_29);
         StorageDead(_28);
-        StorageDead(_26);
+        goto -> bb20;
-        StorageDead(_24);
+    }
+
+    bb20: {
+        StorageDead(_27);
+        StorageDead(_25);
         StorageDead(_23);
+        StorageDead(_22);
         _0 = const ();
         return;
     }
 
-    bb19 (cleanup): {
+    bb21 (cleanup): {
         resume;
     }
 }

tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.panic-abort.diff

@@ -32,12 +32,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_8);
           _8 = _1;
           _9 = Len((*_2));
@@ -52,6 +52,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;
       }

tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.panic-unwind.diff

@@ -32,12 +32,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_8);
           _8 = _1;
           _9 = Len((*_2));
@@ -52,6 +52,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;
       }

tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.panic-abort.diff

@@ -35,12 +35,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_8);
           _8 = _1;
           _9 = Len((*_2));
@@ -55,6 +55,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_11);
           _11 = const 0_usize;
           _12 = Len((*_2));

tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.panic-unwind.diff

@@ -35,12 +35,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_8);
           _8 = _1;
           _9 = Len((*_2));
@@ -55,6 +55,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_11);
           _11 = const 0_usize;
           _12 = Len((*_2));

tests/mir-opt/lower_slice_len.bound.LowerSliceLenCalls.panic-abort.diff

@@ -28,12 +28,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_7);
           _7 = _1;
           _8 = Len((*_2));
@@ -48,6 +48,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;
       }

tests/mir-opt/lower_slice_len.bound.LowerSliceLenCalls.panic-unwind.diff

@@ -28,12 +28,12 @@
       bb1: {
           StorageDead(_6);
           _3 = Lt(move _4, move _5);
-          StorageDead(_5);
-          StorageDead(_4);
           switchInt(move _3) -> [0: bb4, otherwise: bb2];
       }
   
       bb2: {
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_7);
           _7 = _1;
           _8 = Len((*_2));
@@ -48,6 +48,8 @@
       }
   
       bb4: {
+          StorageDead(_5);
+          StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;
       }

tests/mir-opt/matches_reduce_branches.match_nested_if.MatchBranchSimplification.diff

@@ -40,39 +40,43 @@
 -     }
 - 
 -     bb3: {
-+         StorageLive(_7);
-+         _7 = move _6;
-+         _5 = Ne(_7, const false);
-+         StorageDead(_7);
-          StorageDead(_6);
 -         switchInt(move _5) -> [0: bb5, otherwise: bb4];
 -     }
 - 
 -     bb4: {
++         StorageLive(_7);
++         _7 = move _6;
++         _5 = Ne(_7, const false);
++         StorageDead(_7);
++         StorageLive(_8);
++         _8 = move _5;
+          StorageDead(_6);
 -         _4 = const true;
 -         goto -> bb6;
 -     }
 - 
 -     bb5: {
+-         StorageDead(_6);
 -         _4 = const false;
 -         goto -> bb6;
 -     }
 - 
 -     bb6: {
-+         StorageLive(_8);
-+         _8 = move _5;
-+         _4 = Ne(_8, const false);
-+         StorageDead(_8);
-          StorageDead(_5);
 -         switchInt(move _4) -> [0: bb8, otherwise: bb7];
 -     }
 - 
 -     bb7: {
++         _4 = Ne(_8, const false);
++         StorageDead(_8);
++         StorageLive(_9);
++         _9 = move _4;
+          StorageDead(_5);
 -         _3 = const true;
 -         goto -> bb9;
 -     }
 - 
 -     bb8: {
+-         StorageDead(_5);
 -         _3 = const false;
 -         goto -> bb9;
 -     }
@@ -82,8 +86,6 @@
 -     }
 - 
 -     bb10: {
-+         StorageLive(_9);
-+         _9 = move _4;
 +         _3 = Ne(_9, const false);
 +         StorageDead(_9);
 +         StorageLive(_10);

tests/mir-opt/not_equal_false.opt.InstSimplify.diff

@@ -13,16 +13,17 @@
           _3 = _1;
 -         _2 = Ne(move _3, const false);
 +         _2 = move _3;
-          StorageDead(_3);
           switchInt(move _2) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
+          StorageDead(_3);
           _0 = const 0_u32;
           goto -> bb3;
       }
   
       bb2: {
+          StorageDead(_3);
           _0 = const 1_u32;
           goto -> bb3;
       }

tests/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.panic-abort.mir

@@ -19,17 +19,16 @@ fn array_casts() -> () {
     let mut _18: &usize;
     let _19: usize;
     let mut _22: bool;
-    let mut _23: bool;
+    let mut _23: usize;
     let mut _24: usize;
-    let mut _25: usize;
+    let mut _25: !;
-    let mut _26: !;
+    let _27: !;
-    let _28: !;
+    let mut _28: core::panicking::AssertKind;
-    let mut _29: core::panicking::AssertKind;
+    let mut _29: &usize;
-    let mut _30: &usize;
+    let _30: &usize;
-    let _31: &usize;
+    let mut _31: &usize;
-    let mut _32: &usize;
+    let _32: &usize;
-    let _33: &usize;
+    let mut _33: std::option::Option<std::fmt::Arguments<'_>>;
-    let mut _34: std::option::Option<std::fmt::Arguments<'_>>;
     scope 1 {
         debug x => _1;
         let _2: *mut usize;
@@ -45,15 +44,15 @@ fn array_casts() -> () {
                     debug p => _9;
                     let _20: &usize;
                     let _21: &usize;
-                    let mut _35: &usize;
+                    let mut _34: &usize;
                     scope 6 {
                     }
                     scope 7 {
                         debug left_val => _20;
                         debug right_val => _21;
-                        let _27: core::panicking::AssertKind;
+                        let _26: core::panicking::AssertKind;
                         scope 8 {
-                            debug kind => _27;
+                            debug kind => _26;
                         }
                     }
                 }
@@ -110,9 +109,9 @@ fn array_casts() -> () {
         _15 = (*_16);
         _14 = &_15;
         StorageLive(_18);
-        _35 = const _;
+        _34 = const _;
-        Retag(_35);
+        Retag(_34);
-        _18 = &(*_35);
+        _18 = &(*_34);
         _13 = (move _14, move _18);
         Retag(_13);
         StorageDead(_18);
@@ -125,39 +124,16 @@ fn array_casts() -> () {
         Retag(_21);
         StorageLive(_22);
         StorageLive(_23);
+        _23 = (*_20);
         StorageLive(_24);
-        _24 = (*_20);
+        _24 = (*_21);
-        StorageLive(_25);
+        _22 = Eq(move _23, move _24);
-        _25 = (*_21);
-        _23 = Eq(move _24, move _25);
-        StorageDead(_25);
-        StorageDead(_24);
-        _22 = Not(move _23);
-        StorageDead(_23);
         switchInt(move _22) -> [0: bb4, otherwise: bb3];
     }
 
     bb3: {
-        StorageLive(_27);
+        StorageDead(_24);
-        _27 = core::panicking::AssertKind::Eq;
+        StorageDead(_23);
-        StorageLive(_28);
-        StorageLive(_29);
-        _29 = move _27;
-        StorageLive(_30);
-        StorageLive(_31);
-        _31 = &(*_20);
-        _30 = &(*_31);
-        StorageLive(_32);
-        StorageLive(_33);
-        _33 = &(*_21);
-        _32 = &(*_33);
-        StorageLive(_34);
-        _34 = Option::<Arguments<'_>>::None;
-        Retag(_34);
-        _28 = core::panicking::assert_failed::<usize, usize>(move _29, move _30, move _32, move _34) -> unwind unreachable;
-    }
-
-    bb4: {
         _12 = const ();
         StorageDead(_22);
         StorageDead(_21);
@@ -173,4 +149,26 @@ fn array_casts() -> () {
         StorageDead(_1);
         return;
     }
+
+    bb4: {
+        StorageDead(_24);
+        StorageDead(_23);
+        StorageLive(_26);
+        _26 = core::panicking::AssertKind::Eq;
+        StorageLive(_27);
+        StorageLive(_28);
+        _28 = move _26;
+        StorageLive(_29);
+        StorageLive(_30);
+        _30 = &(*_20);
+        _29 = &(*_30);
+        StorageLive(_31);
+        StorageLive(_32);
+        _32 = &(*_21);
+        _31 = &(*_32);
+        StorageLive(_33);
+        _33 = Option::<Arguments<'_>>::None;
+        Retag(_33);
+        _27 = core::panicking::assert_failed::<usize, usize>(move _28, move _29, move _31, move _33) -> unwind unreachable;
+    }
 }

tests/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.panic-unwind.mir

@@ -19,17 +19,16 @@ fn array_casts() -> () {
     let mut _18: &usize;
     let _19: usize;
     let mut _22: bool;
-    let mut _23: bool;
+    let mut _23: usize;
     let mut _24: usize;
-    let mut _25: usize;
+    let mut _25: !;
-    let mut _26: !;
+    let _27: !;
-    let _28: !;
+    let mut _28: core::panicking::AssertKind;
-    let mut _29: core::panicking::AssertKind;
+    let mut _29: &usize;
-    let mut _30: &usize;
+    let _30: &usize;
-    let _31: &usize;
+    let mut _31: &usize;
-    let mut _32: &usize;
+    let _32: &usize;
-    let _33: &usize;
+    let mut _33: std::option::Option<std::fmt::Arguments<'_>>;
-    let mut _34: std::option::Option<std::fmt::Arguments<'_>>;
     scope 1 {
         debug x => _1;
         let _2: *mut usize;
@@ -45,15 +44,15 @@ fn array_casts() -> () {
                     debug p => _9;
                     let _20: &usize;
                     let _21: &usize;
-                    let mut _35: &usize;
+                    let mut _34: &usize;
                     scope 6 {
                     }
                     scope 7 {
                         debug left_val => _20;
                         debug right_val => _21;
-                        let _27: core::panicking::AssertKind;
+                        let _26: core::panicking::AssertKind;
                         scope 8 {
-                            debug kind => _27;
+                            debug kind => _26;
                         }
                     }
                 }
@@ -110,9 +109,9 @@ fn array_casts() -> () {
         _15 = (*_16);
         _14 = &_15;
         StorageLive(_18);
-        _35 = const _;
+        _34 = const _;
-        Retag(_35);
+        Retag(_34);
-        _18 = &(*_35);
+        _18 = &(*_34);
         _13 = (move _14, move _18);
         Retag(_13);
         StorageDead(_18);
@@ -125,39 +124,16 @@ fn array_casts() -> () {
         Retag(_21);
         StorageLive(_22);
         StorageLive(_23);
+        _23 = (*_20);
         StorageLive(_24);
-        _24 = (*_20);
+        _24 = (*_21);
-        StorageLive(_25);
+        _22 = Eq(move _23, move _24);
-        _25 = (*_21);
-        _23 = Eq(move _24, move _25);
-        StorageDead(_25);
-        StorageDead(_24);
-        _22 = Not(move _23);
-        StorageDead(_23);
         switchInt(move _22) -> [0: bb4, otherwise: bb3];
     }
 
     bb3: {
-        StorageLive(_27);
+        StorageDead(_24);
-        _27 = core::panicking::AssertKind::Eq;
+        StorageDead(_23);
-        StorageLive(_28);
-        StorageLive(_29);
-        _29 = move _27;
-        StorageLive(_30);
-        StorageLive(_31);
-        _31 = &(*_20);
-        _30 = &(*_31);
-        StorageLive(_32);
-        StorageLive(_33);
-        _33 = &(*_21);
-        _32 = &(*_33);
-        StorageLive(_34);
-        _34 = Option::<Arguments<'_>>::None;
-        Retag(_34);
-        _28 = core::panicking::assert_failed::<usize, usize>(move _29, move _30, move _32, move _34) -> unwind continue;
-    }
-
-    bb4: {
         _12 = const ();
         StorageDead(_22);
         StorageDead(_21);
@@ -173,4 +149,26 @@ fn array_casts() -> () {
         StorageDead(_1);
         return;
     }
+
+    bb4: {
+        StorageDead(_24);
+        StorageDead(_23);
+        StorageLive(_26);
+        _26 = core::panicking::AssertKind::Eq;
+        StorageLive(_27);
+        StorageLive(_28);
+        _28 = move _26;
+        StorageLive(_29);
+        StorageLive(_30);
+        _30 = &(*_20);
+        _29 = &(*_30);
+        StorageLive(_31);
+        StorageLive(_32);
+        _32 = &(*_21);
+        _31 = &(*_32);
+        StorageLive(_33);
+        _33 = Option::<Arguments<'_>>::None;
+        Retag(_33);
+        _27 = core::panicking::assert_failed::<usize, usize>(move _28, move _29, move _31, move _33) -> unwind continue;
+    }
 }

tests/ui/rfcs/rfc-2497-if-let-chains/chains-without-let.rs

@@ -1,7 +1,6 @@
 fn and_chain() {
     let z;
     if true && { z = 3; true} && z == 3 {}
-    //~^ ERROR E0381
 }
 
 fn and_chain_2() {
@@ -13,7 +12,6 @@ fn and_chain_2() {
 fn or_chain() {
     let z;
     if false || { z = 3; false} || z == 3 {}
-    //~^ ERROR E0381
 }
 
 fn main() {

tests/ui/rfcs/rfc-2497-if-let-chains/chains-without-let.stderr

@@ -1,15 +1,5 @@
 error[E0381]: used binding `z` is possibly-uninitialized
-  --> $DIR/chains-without-let.rs:3:34
+  --> $DIR/chains-without-let.rs:8:31
-   |
-LL |     let z;
-   |         - binding declared here but left uninitialized
-LL |     if true && { z = 3; true} && z == 3 {}
-   |                  -----           ^ `z` used here but it is possibly-uninitialized
-   |                  |
-   |                  binding initialized here in some conditions
-
-error[E0381]: used binding `z` is possibly-uninitialized
-  --> $DIR/chains-without-let.rs:9:31
    |
 LL |     let z;
    |         - binding declared here but left uninitialized
@@ -18,16 +8,6 @@ LL |     true && { z = 3; true} && z == 3;
    |               |
    |               binding initialized here in some conditions
 
-error[E0381]: used binding `z` is possibly-uninitialized
+error: aborting due to previous error
-  --> $DIR/chains-without-let.rs:15:36
-   |
-LL |     let z;
-   |         - binding declared here but left uninitialized
-LL |     if false || { z = 3; false} || z == 3 {}
-   |                   -----            ^ `z` used here but it is possibly-uninitialized
-   |                   |
-   |                   binding initialized here in some conditions
-
-error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0381`.