Auto merge of #74839 - alarsyo:multiple_return_terminators, r=oli-obk

Implement multiple return terminator optimization

Closes #72022

compiler/rustc_mir/src/transform/mod.rs

@@ -33,6 +33,7 @@ pub mod inline;
 pub mod instcombine;
 pub mod instrument_coverage;
 pub mod match_branches;
+pub mod multiple_return_terminators;
 pub mod no_landing_pads;
 pub mod nrvo;
 pub mod promote_consts;
@@ -464,6 +465,7 @@ fn run_optimization_passes<'tcx>(
         &remove_unneeded_drops::RemoveUnneededDrops,
         &match_branches::MatchBranchSimplification,
         // inst combine is after MatchBranchSimplification to clean up Ne(_1, false)
+        &multiple_return_terminators::MultipleReturnTerminators,
         &instcombine::InstCombine,
         &const_prop::ConstProp,
         &simplify_branches::SimplifyBranches::new("after-const-prop"),
@@ -478,6 +480,7 @@ fn run_optimization_passes<'tcx>(
         &simplify::SimplifyCfg::new("final"),
         &nrvo::RenameReturnPlace,
         &simplify::SimplifyLocals,
+        &multiple_return_terminators::MultipleReturnTerminators,
     ];
 
     // Optimizations to run even if mir optimizations have been disabled.

compiler/rustc_mir/src/transform/multiple_return_terminators.rs

@@ -0,0 +1,38 @@
+//! This pass removes jumps to basic blocks containing only a return, and replaces them with a
+//! return instead.
+
+use crate::transform::{simplify, MirPass, MirSource};
+use rustc_index::bit_set::BitSet;
+use rustc_middle::mir::*;
+use rustc_middle::ty::TyCtxt;
+
+pub struct MultipleReturnTerminators;
+
+impl<'tcx> MirPass<'tcx> for MultipleReturnTerminators {
+    fn run_pass(&self, tcx: TyCtxt<'tcx>, _: MirSource<'tcx>, body: &mut Body<'tcx>) {
+        if tcx.sess.opts.debugging_opts.mir_opt_level < 3 {
+            return;
+        }
+
+        // find basic blocks with no statement and a return terminator
+        let mut bbs_simple_returns = BitSet::new_empty(body.basic_blocks().len());
+        let bbs = body.basic_blocks_mut();
+        for idx in bbs.indices() {
+            if bbs[idx].statements.is_empty()
+                && bbs[idx].terminator().kind == TerminatorKind::Return
+            {
+                bbs_simple_returns.insert(idx);
+            }
+        }
+
+        for bb in bbs {
+            if let TerminatorKind::Goto { target } = bb.terminator().kind {
+                if bbs_simple_returns.contains(target) {
+                    bb.terminator_mut().kind = TerminatorKind::Return;
+                }
+            }
+        }
+
+        simplify::remove_dead_blocks(body)
+    }
+}

src/test/mir-opt/early_otherwise_branch_68867.try_sum.EarlyOtherwiseBranch.before-SimplifyBranches-after-copy-prop.after.diff

@@ -91,7 +91,7 @@
 +         StorageLive(_35);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
 +         _35 = Ne(_34, _11);              // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
 +         StorageDead(_34);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
-+         switchInt(move _35) -> [false: bb8, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
++         switchInt(move _35) -> [false: bb7, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
       }
   
       bb1: {
@@ -107,10 +107,9 @@
           StorageDead(_33);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:27: 27:28
 -         StorageDead(_3);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
 -         StorageDead(_4);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
--         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
-+         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
+          return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
       }
   
 +     bb2: {
@@ -131,7 +130,7 @@
 +         nop;                             // scope 1 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
 +     }
 + 
       bb3: {
@@ -154,7 +153,7 @@
 +         nop;                             // scope 2 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
       bb4: {
@@ -177,7 +176,7 @@
 +         nop;                             // scope 3 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
       bb5: {
@@ -200,7 +199,7 @@
 +         nop;                             // scope 4 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
 +         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
       bb6: {
@@ -221,7 +220,11 @@
 -         StorageDead(_14);                // scope 1 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
 -         StorageDead(_13);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
 -         StorageDead(_12);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
++         discriminant(_0) = 0;            // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
++         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
++         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
 +         return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
       }
   
@@ -243,15 +246,10 @@
 -         StorageDead(_19);                // scope 2 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
 -         StorageDead(_18);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
 -         StorageDead(_17);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
-+         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
+-     }
-+         discriminant(_0) = 0;            // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
+- 
-+         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
+-     bb8: {
-+         nop;                             // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
-+         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
-      }
-  
-      bb8: {
 -         StorageLive(_22);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:16: 25:19
 -         _22 = (((*(_4.0: &ViewportPercentageLength)) as Vmin).0: f32); // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:16: 25:19
 -         StorageLive(_23);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:28: 25:33
@@ -269,7 +267,7 @@
 -         StorageDead(_24);                // scope 3 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
 -         StorageDead(_23);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
 -         StorageDead(_22);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
 -     }
 - 
 -     bb9: {
@@ -290,19 +288,15 @@
 -         StorageDead(_29);                // scope 4 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
 -         StorageDead(_28);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
 -         StorageDead(_27);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
 -     }
 - 
 -     bb10: {
--         return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
--     }
-- 
--     bb11: {
 -         ((_0 as Ok).0: ViewportPercentageLength) = move _3; // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
 -         discriminant(_0) = 0;            // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
 -         StorageDead(_3);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
 -         StorageDead(_4);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
--         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
+-         return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
 +         StorageDead(_35);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:21: 23:30
 +         switchInt(_11) -> [0_isize: bb2, 1_isize: bb3, 2_isize: bb4, 3_isize: bb5, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:21: 23:30
       }

src/test/mir-opt/early_otherwise_branch_68867.try_sum.EarlyOtherwiseBranch.diff

@@ -73,7 +73,7 @@
 +         StorageLive(_35);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
 +         _35 = Ne(_34, _11);              // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
 +         StorageDead(_34);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
-+         switchInt(move _35) -> [false: bb8, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
++         switchInt(move _35) -> [false: bb7, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:11: 23:18
       }
   
       bb1: {
@@ -89,8 +89,7 @@
           StorageDead(_33);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:27: 27:28
           StorageDead(_3);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
           StorageDead(_4);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
--         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
+          return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
-+         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:27:14: 27:28
       }
   
 -     bb3: {
@@ -127,8 +126,8 @@
           StorageDead(_14);                // scope 1 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
           StorageDead(_13);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
           StorageDead(_12);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:49: 23:50
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
 -     bb7: {
@@ -150,8 +149,8 @@
           StorageDead(_19);                // scope 2 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
           StorageDead(_18);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
           StorageDead(_17);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:24:49: 24:50
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
 -     bb8: {
@@ -173,8 +172,8 @@
           StorageDead(_24);                // scope 3 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
           StorageDead(_23);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
           StorageDead(_22);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:25:55: 25:56
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
 -     bb9: {
@@ -196,26 +195,20 @@
           StorageDead(_29);                // scope 4 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
           StorageDead(_28);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
           StorageDead(_27);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:26:55: 26:56
--         goto -> bb11;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
+-         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
-+         goto -> bb7;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
++         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:8: 28:6
       }
   
 -     bb10: {
 +     bb6: {
-          return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
-      }
-  
--     bb11: {
-+     bb7: {
           ((_0 as Ok).0: ViewportPercentageLength) = move _3; // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
           discriminant(_0) = 0;            // scope 0 at $DIR/early_otherwise_branch_68867.rs:22:5: 28:7
           StorageDead(_3);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:28:6: 28:7
           StorageDead(_4);                 // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:1: 29:2
--         goto -> bb10;                    // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
+          return;                          // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
-+         goto -> bb6;                     // scope 0 at $DIR/early_otherwise_branch_68867.rs:29:2: 29:2
 +     }
 + 
-+     bb8: {
++     bb7: {
 +         StorageDead(_35);                // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:21: 23:30
 +         switchInt(_11) -> [0_isize: bb2, 1_isize: bb3, 2_isize: bb4, 3_isize: bb5, otherwise: bb1]; // scope 0 at $DIR/early_otherwise_branch_68867.rs:23:21: 23:30
       }

src/test/mir-opt/issue_73223.main.SimplifyArmIdentity.32bit.diff

@@ -106,7 +106,7 @@
           _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
           StorageDead(_2);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
           StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+          return;                          // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
       }
   
       bb2: {
@@ -153,14 +153,10 @@
           StorageDead(_17);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           _15 = Not(move _16);             // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_16);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          switchInt(_15) -> [false: bb4, otherwise: bb5]; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+          switchInt(_15) -> [false: bb3, otherwise: bb4]; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       }
   
       bb3: {
-          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
-      }
-  
-      bb4: {
           _8 = const ();                   // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_15);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_14);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
@@ -170,10 +166,10 @@
           _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
           StorageDead(_6);                 // scope 1 at $DIR/issue-73223.rs:9:1: 9:2
           StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
+          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
       }
   
-      bb5: {
+      bb4: {
           StorageLive(_19);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
           StorageLive(_20);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
           StorageLive(_21);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
@@ -224,24 +220,24 @@
           StorageLive(_46);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_47);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _47 = _40;                       // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _46 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _47) -> bb6; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _46 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _47) -> bb5; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) -> for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {std::intrinsics::transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb6: {
+      bb5: {
           StorageDead(_47);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_48);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_49);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _49 = _39;                       // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _48 = transmute::<&&i32, &core::fmt::Opaque>(move _49) -> bb7; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _48 = transmute::<&&i32, &core::fmt::Opaque>(move _49) -> bb6; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb7: {
+      bb6: {
           StorageDead(_49);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_38.0: &core::fmt::Opaque) = move _48; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_38.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _46; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
@@ -260,24 +256,24 @@
           StorageLive(_50);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_51);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _51 = _43;                       // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _50 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _51) -> bb8; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _50 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _51) -> bb7; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) -> for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {std::intrinsics::transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb8: {
+      bb7: {
           StorageDead(_51);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_52);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_53);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _53 = _42;                       // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _52 = transmute::<&&i32, &core::fmt::Opaque>(move _53) -> bb9; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _52 = transmute::<&&i32, &core::fmt::Opaque>(move _53) -> bb8; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb9: {
+      bb8: {
           StorageDead(_53);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_41.0: &core::fmt::Opaque) = move _52; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_41.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _50; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL

src/test/mir-opt/issue_73223.main.SimplifyArmIdentity.64bit.diff

@@ -106,7 +106,7 @@
           _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
           StorageDead(_2);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
           StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+          return;                          // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
       }
   
       bb2: {
@@ -153,14 +153,10 @@
           StorageDead(_17);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           _15 = Not(move _16);             // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_16);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          switchInt(_15) -> [false: bb4, otherwise: bb5]; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+          switchInt(_15) -> [false: bb3, otherwise: bb4]; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       }
   
       bb3: {
-          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
-      }
-  
-      bb4: {
           _8 = const ();                   // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_15);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           StorageDead(_14);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
@@ -170,10 +166,10 @@
           _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
           StorageDead(_6);                 // scope 1 at $DIR/issue-73223.rs:9:1: 9:2
           StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
+          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
       }
   
-      bb5: {
+      bb4: {
           StorageLive(_19);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
           StorageLive(_20);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
           StorageLive(_21);                // scope 4 at $SRC_DIR/std/src/macros.rs:LL:COL
@@ -224,24 +220,24 @@
           StorageLive(_46);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_47);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _47 = _40;                       // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _46 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _47) -> bb6; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _46 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _47) -> bb5; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) -> for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {std::intrinsics::transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb6: {
+      bb5: {
           StorageDead(_47);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_48);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_49);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _49 = _39;                       // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _48 = transmute::<&&i32, &core::fmt::Opaque>(move _49) -> bb7; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _48 = transmute::<&&i32, &core::fmt::Opaque>(move _49) -> bb6; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb7: {
+      bb6: {
           StorageDead(_49);                // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_38.0: &core::fmt::Opaque) = move _48; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_38.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _46; // scope 7 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
@@ -260,24 +256,24 @@
           StorageLive(_50);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_51);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _51 = _43;                       // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _50 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _51) -> bb8; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _50 = transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>(move _51) -> bb7; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) -> for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {std::intrinsics::transmute::<for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>, for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb8: {
+      bb7: {
           StorageDead(_51);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_52);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           StorageLive(_53);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           _53 = _42;                       // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
-          _52 = transmute::<&&i32, &core::fmt::Opaque>(move _53) -> bb9; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
+          _52 = transmute::<&&i32, &core::fmt::Opaque>(move _53) -> bb8; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
                                            // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}, val: Value(Scalar(<ZST>)) }
       }
   
-      bb9: {
+      bb8: {
           StorageDead(_53);                // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_41.0: &core::fmt::Opaque) = move _52; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL
           (_41.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _50; // scope 9 at $SRC_DIR/core/src/fmt/mod.rs:LL:COL

src/test/mir-opt/multiple_return_terminators.rs

@@ -0,0 +1,14 @@
+// compile-flags: -Z mir-opt-level=3
+// EMIT_MIR multiple_return_terminators.test.MultipleReturnTerminators.diff
+
+fn test(x: bool) {
+    if x {
+        // test
+    } else {
+        // test
+    }
+}
+
+fn main() {
+    test(true)
+}

src/test/mir-opt/multiple_return_terminators.test.MultipleReturnTerminators.diff

@@ -0,0 +1,30 @@
+- // MIR for `test` before MultipleReturnTerminators
++ // MIR for `test` after MultipleReturnTerminators
+  
+  fn test(_1: bool) -> () {
+      debug x => _1;                       // in scope 0 at $DIR/multiple_return_terminators.rs:4:9: 4:10
+      let mut _0: ();                      // return place in scope 0 at $DIR/multiple_return_terminators.rs:4:18: 4:18
+      let mut _2: bool;                    // in scope 0 at $DIR/multiple_return_terminators.rs:5:8: 5:9
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/multiple_return_terminators.rs:5:8: 5:9
+          _2 = _1;                         // scope 0 at $DIR/multiple_return_terminators.rs:5:8: 5:9
+          switchInt(_2) -> [false: bb1, otherwise: bb2]; // scope 0 at $DIR/multiple_return_terminators.rs:5:5: 9:6
+      }
+  
+      bb1: {
+          _0 = const ();                   // scope 0 at $DIR/multiple_return_terminators.rs:7:12: 9:6
+          goto -> bb3;                     // scope 0 at $DIR/multiple_return_terminators.rs:5:5: 9:6
+      }
+  
+      bb2: {
+          _0 = const ();                   // scope 0 at $DIR/multiple_return_terminators.rs:5:10: 7:6
+          goto -> bb3;                     // scope 0 at $DIR/multiple_return_terminators.rs:5:5: 9:6
+      }
+  
+      bb3: {
+          StorageDead(_2);                 // scope 0 at $DIR/multiple_return_terminators.rs:10:1: 10:2
+          return;                          // scope 0 at $DIR/multiple_return_terminators.rs:10:2: 10:2
+      }
+  }
+  

src/test/mir-opt/not_equal_false.opt.InstCombine.diff

@@ -13,60 +13,35 @@
           StorageLive(_2);                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           _3 = discriminant(_1);           // scope 0 at $DIR/not_equal_false.rs:4:17: 4:21
           _2 = Eq(_3, const 0_isize);      // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb7;                     // scope 0 at $DIR/not_equal_false.rs:4:17: 4:21
+          goto -> bb4;                     // scope 0 at $DIR/not_equal_false.rs:4:17: 4:21
       }
   
       bb1: {
           _0 = const true;                 // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
-          goto -> bb4;                     // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
+          goto -> bb3;                     // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
       }
   
       bb2: {
-          _0 = const false;                // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
-          goto -> bb4;                     // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
-      }
-  
-      bb3: {
           StorageLive(_4);                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
           _5 = discriminant(_1);           // scope 0 at $DIR/not_equal_false.rs:4:38: 4:45
           _4 = Eq(_5, const 1_isize);      // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb10;                    // scope 0 at $DIR/not_equal_false.rs:4:38: 4:45
+          goto -> bb5;                     // scope 0 at $DIR/not_equal_false.rs:4:38: 4:45
       }
   
-      bb4: {
+      bb3: {
           StorageDead(_4);                 // scope 0 at $DIR/not_equal_false.rs:4:45: 4:46
           StorageDead(_2);                 // scope 0 at $DIR/not_equal_false.rs:4:45: 4:46
           return;                          // scope 0 at $DIR/not_equal_false.rs:5:2: 5:2
       }
   
+      bb4: {
+          switchInt(move _2) -> [false: bb2, otherwise: bb1]; // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
+      }
+  
       bb5: {
-          _2 = const false;                // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb7;                     // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      }
-  
-      bb6: {
-          _2 = const true;                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb7;                     // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      }
-  
-      bb7: {
-          switchInt(move _2) -> [false: bb3, otherwise: bb1]; // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
-      }
-  
-      bb8: {
-          _4 = const false;                // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb10;                    // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      }
-  
-      bb9: {
-          _4 = const true;                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          goto -> bb10;                    // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      }
-  
-      bb10: {
 -         _0 = Ne(_4, const false);        // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
 +         _0 = _4;                         // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
-          goto -> bb4;                     // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
+          goto -> bb3;                     // scope 0 at $DIR/not_equal_false.rs:4:5: 4:46
       }
   }
   

src/test/mir-opt/simplify_try.try_identity.DestinationPropagation.diff

@@ -62,10 +62,6 @@
 +         nop;                             // scope 1 at $DIR/simplify_try.rs:8:5: 8:10
 +         nop;                             // scope 0 at $DIR/simplify_try.rs:7:15: 7:16
           StorageDead(_2);                 // scope 0 at $DIR/simplify_try.rs:9:1: 9:2
-          goto -> bb2;                     // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
-      }
-  
-      bb2: {
           return;                          // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
       }
   }

src/test/mir-opt/simplify_try.try_identity.SimplifyArmIdentity.diff

@@ -67,7 +67,7 @@
 -         discriminant(_0) = 0;            // scope 1 at $DIR/simplify_try.rs:8:5: 8:10
 -         StorageDead(_11);                // scope 1 at $DIR/simplify_try.rs:8:9: 8:10
           StorageDead(_2);                 // scope 0 at $DIR/simplify_try.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
+          return;                          // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
       }
   
       bb2: {
@@ -88,11 +88,7 @@
 +         _0 = move _3;                    // scope 8 at $SRC_DIR/core/src/result.rs:LL:COL
           StorageDead(_3);                 // scope 0 at $DIR/simplify_try.rs:7:15: 7:16
           StorageDead(_2);                 // scope 0 at $DIR/simplify_try.rs:9:1: 9:2
-          goto -> bb3;                     // scope 0 at $DIR/simplify_try.rs:7:14: 7:15
+          return;                          // scope 0 at $DIR/simplify_try.rs:7:14: 7:15
-      }
-  
-      bb3: {
-          return;                          // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
       }
   }
   

src/test/mir-opt/simplify_try.try_identity.SimplifyBranchSame.after.mir

@@ -52,10 +52,6 @@ fn try_identity(_1: std::result::Result<u32, i32>) -> std::result::Result<u32, i
         _0 = move _3;                    // scope 1 at $DIR/simplify_try.rs:8:5: 8:10
         StorageDead(_3);                 // scope 0 at $DIR/simplify_try.rs:7:15: 7:16
         StorageDead(_2);                 // scope 0 at $DIR/simplify_try.rs:9:1: 9:2
-        goto -> bb2;                     // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
-    }
-
-    bb2: {
         return;                          // scope 0 at $DIR/simplify_try.rs:9:2: 9:2
     }
 }