Rollup merge of #73949 - wesleywiser:simplify_try_fixes, r=oli-obk

[mir-opt] Fix mis-optimization and other issues with the SimplifyArmIdentity pass

This does not yet attempt re-enabling the pass, but it does resolve a number of issues with the pass.

r? @oli-obk

I believe this closes #73223.

12 files changed, 1411 insertions, 35 deletions

diff --git a/src/librustc_middle/mir/mod.rs b/src/librustc_middle/mir/mod.rs
index ad4e8b55b75..31b8de500e0 100644
--- a/src/librustc_middle/mir/mod.rs
+++ b/src/librustc_middle/mir/mod.rs
@@ -257,6 +257,18 @@ impl<'tcx> Body<'tcx> {
         (&mut self.basic_blocks, &mut self.local_decls)
     }
 
+    #[inline]
+    pub fn basic_blocks_local_decls_mut_and_var_debug_info(
+        &mut self,
+    ) -> (
+        &mut IndexVec<BasicBlock, BasicBlockData<'tcx>>,
+        &mut LocalDecls<'tcx>,
+        &mut Vec<VarDebugInfo<'tcx>>,
+    ) {
+        self.predecessor_cache.invalidate();
+        (&mut self.basic_blocks, &mut self.local_decls, &mut self.var_debug_info)
+    }
+
     /// Returns `true` if a cycle exists in the control-flow graph that is reachable from the
     /// `START_BLOCK`.
     pub fn is_cfg_cyclic(&self) -> bool {
diff --git a/src/librustc_mir/transform/simplify_try.rs b/src/librustc_mir/transform/simplify_try.rs
index 50136ac3bec..97a01de867e 100644
--- a/src/librustc_mir/transform/simplify_try.rs
+++ b/src/librustc_mir/transform/simplify_try.rs
@@ -11,9 +11,10 @@
 
 use crate::transform::{simplify, MirPass, MirSource};
 use itertools::Itertools as _;
-use rustc_index::vec::IndexVec;
+use rustc_index::{bit_set::BitSet, vec::IndexVec};
+use rustc_middle::mir::visit::{NonUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::{Ty, TyCtxt};
+use rustc_middle::ty::{List, Ty, TyCtxt};
 use rustc_target::abi::VariantIdx;
 use std::iter::{Enumerate, Peekable};
 use std::slice::Iter;
@@ -73,9 +74,20 @@ struct ArmIdentityInfo<'tcx> {
 
     /// The statements that should be removed (turned into nops)
     stmts_to_remove: Vec<usize>,
+
+    /// Indices of debug variables that need to be adjusted to point to
+    // `{local_0}.{dbg_projection}`.
+    dbg_info_to_adjust: Vec<usize>,
+
+    /// The projection used to rewrite debug info.
+    dbg_projection: &'tcx List<PlaceElem<'tcx>>,
 }
 
-fn get_arm_identity_info<'a, 'tcx>(stmts: &'a [Statement<'tcx>]) -> Option<ArmIdentityInfo<'tcx>> {
+fn get_arm_identity_info<'a, 'tcx>(
+    stmts: &'a [Statement<'tcx>],
+    locals_count: usize,
+    debug_info: &'a [VarDebugInfo<'tcx>],
+) -> Option<ArmIdentityInfo<'tcx>> {
     // This can't possibly match unless there are at least 3 statements in the block
     // so fail fast on tiny blocks.
     if stmts.len() < 3 {
@@ -187,7 +199,7 @@ fn get_arm_identity_info<'a, 'tcx>(stmts: &'a [Statement<'tcx>]) -> Option<ArmId
     try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
 
     let (get_variant_field_stmt, stmt) = stmt_iter.next()?;
-    let (local_tmp_s0, local_1, vf_s0) = match_get_variant_field(stmt)?;
+    let (local_tmp_s0, local_1, vf_s0, dbg_projection) = match_get_variant_field(stmt)?;
 
     try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
 
@@ -228,6 +240,19 @@ fn get_arm_identity_info<'a, 'tcx>(stmts: &'a [Statement<'tcx>]) -> Option<ArmId
     let stmt_to_overwrite =
         nop_stmts.iter().find(|stmt_idx| live_idx < **stmt_idx && **stmt_idx < dead_idx);
 
+    let mut tmp_assigned_vars = BitSet::new_empty(locals_count);
+    for (l, r) in &tmp_assigns {
+        tmp_assigned_vars.insert(*l);
+        tmp_assigned_vars.insert(*r);
+    }
+
+    let mut dbg_info_to_adjust = Vec::new();
+    for (i, var_info) in debug_info.iter().enumerate() {
+        if tmp_assigned_vars.contains(var_info.place.local) {
+            dbg_info_to_adjust.push(i);
+        }
+    }
+
     Some(ArmIdentityInfo {
         local_temp_0: local_tmp_s0,
         local_1,
@@ -243,12 +268,16 @@ fn get_arm_identity_info<'a, 'tcx>(stmts: &'a [Statement<'tcx>]) -> Option<ArmId
         source_info: discr_stmt_source_info,
         storage_stmts,
         stmts_to_remove: nop_stmts,
+        dbg_info_to_adjust,
+        dbg_projection,
     })
 }
 
 fn optimization_applies<'tcx>(
     opt_info: &ArmIdentityInfo<'tcx>,
     local_decls: &IndexVec<Local, LocalDecl<'tcx>>,
+    local_uses: &IndexVec<Local, usize>,
+    var_debug_info: &[VarDebugInfo<'tcx>],
 ) -> bool {
     trace!("testing if optimization applies...");
 
@@ -273,6 +302,7 @@ fn optimization_applies<'tcx>(
     // Verify the assigment chain consists of the form b = a; c = b; d = c; etc...
     if opt_info.field_tmp_assignments.is_empty() {
         trace!("NO: no assignments found");
+        return false;
     }
     let mut last_assigned_to = opt_info.field_tmp_assignments[0].1;
     let source_local = last_assigned_to;
@@ -285,6 +315,35 @@ fn optimization_applies<'tcx>(
         last_assigned_to = *l;
     }
 
+    // Check that the first and last used locals are only used twice
+    // since they are of the form:
+    //
+    // ```
+    // _first = ((_x as Variant).n: ty);
+    // _n = _first;
+    // ...
+    // ((_y as Variant).n: ty) = _n;
+    // discriminant(_y) = z;
+    // ```
+    for (l, r) in &opt_info.field_tmp_assignments {
+        if local_uses[*l] != 2 {
+            warn!("NO: FAILED assignment chain local {:?} was used more than twice", l);
+            return false;
+        } else if local_uses[*r] != 2 {
+            warn!("NO: FAILED assignment chain local {:?} was used more than twice", r);
+            return false;
+        }
+    }
+
+    // Check that debug info only points to full Locals and not projections.
+    for dbg_idx in &opt_info.dbg_info_to_adjust {
+        let dbg_info = &var_debug_info[*dbg_idx];
+        if !dbg_info.place.projection.is_empty() {
+            trace!("NO: debug info for {:?} had a projection {:?}", dbg_info.name, dbg_info.place);
+            return false;
+        }
+    }
+
     if source_local != opt_info.local_temp_0 {
         trace!(
             "NO: start of assignment chain does not match enum variant temp: {:?} != {:?}",
@@ -312,11 +371,15 @@ impl<'tcx> MirPass<'tcx> for SimplifyArmIdentity {
         }
 
         trace!("running SimplifyArmIdentity on {:?}", source);
-        let (basic_blocks, local_decls) = body.basic_blocks_and_local_decls_mut();
+        let local_uses = LocalUseCounter::get_local_uses(body);
+        let (basic_blocks, local_decls, debug_info) =
+            body.basic_blocks_local_decls_mut_and_var_debug_info();
         for bb in basic_blocks {
-            if let Some(opt_info) = get_arm_identity_info(&bb.statements) {
+            if let Some(opt_info) =
+                get_arm_identity_info(&bb.statements, local_decls.len(), debug_info)
+            {
                 trace!("got opt_info = {:#?}", opt_info);
-                if !optimization_applies(&opt_info, local_decls) {
+                if !optimization_applies(&opt_info, local_decls, &local_uses, &debug_info) {
                     debug!("optimization skipped for {:?}", source);
                     continue;
                 }
@@ -352,23 +415,57 @@ impl<'tcx> MirPass<'tcx> for SimplifyArmIdentity {
 
                 bb.statements.retain(|stmt| stmt.kind != StatementKind::Nop);
 
+                // Fix the debug info to point to the right local
+                for dbg_index in opt_info.dbg_info_to_adjust {
+                    let dbg_info = &mut debug_info[dbg_index];
+                    assert!(dbg_info.place.projection.is_empty());
+                    dbg_info.place.local = opt_info.local_0;
+                    dbg_info.place.projection = opt_info.dbg_projection;
+                }
+
                 trace!("block is now {:?}", bb.statements);
             }
         }
     }
 }
 
+struct LocalUseCounter {
+    local_uses: IndexVec<Local, usize>,
+}
+
+impl LocalUseCounter {
+    fn get_local_uses<'tcx>(body: &Body<'tcx>) -> IndexVec<Local, usize> {
+        let mut counter = LocalUseCounter { local_uses: IndexVec::from_elem(0, &body.local_decls) };
+        counter.visit_body(body);
+        counter.local_uses
+    }
+}
+
+impl<'tcx> Visitor<'tcx> for LocalUseCounter {
+    fn visit_local(&mut self, local: &Local, context: PlaceContext, _location: Location) {
+        if context.is_storage_marker()
+            || context == PlaceContext::NonUse(NonUseContext::VarDebugInfo)
+        {
+            return;
+        }
+
+        self.local_uses[*local] += 1;
+    }
+}
+
 /// Match on:
 /// ```rust
 /// _LOCAL_INTO = ((_LOCAL_FROM as Variant).FIELD: TY);
 /// ```
-fn match_get_variant_field<'tcx>(stmt: &Statement<'tcx>) -> Option<(Local, Local, VarField<'tcx>)> {
+fn match_get_variant_field<'tcx>(
+    stmt: &Statement<'tcx>,
+) -> Option<(Local, Local, VarField<'tcx>, &'tcx List<PlaceElem<'tcx>>)> {
     match &stmt.kind {
         StatementKind::Assign(box (place_into, rvalue_from)) => match rvalue_from {
             Rvalue::Use(Operand::Copy(pf) | Operand::Move(pf)) => {
                 let local_into = place_into.as_local()?;
                 let (local_from, vf) = match_variant_field_place(*pf)?;
-                Some((local_into, local_from, vf))
+                Some((local_into, local_from, vf, pf.projection))
             }
             _ => None,
         },
diff --git a/src/test/mir-opt/issue-73223.rs b/src/test/mir-opt/issue-73223.rs
new file mode 100644
index 00000000000..d93805e6cd1
--- /dev/null
+++ b/src/test/mir-opt/issue-73223.rs
@@ -0,0 +1,13 @@
+fn main() {
+    let split = match Some(1) {
+        Some(v) => v,
+        None => return,
+    };
+
+    let _prev = Some(split);
+    assert_eq!(split, 1);
+}
+
+// EMIT_MIR_FOR_EACH_BIT_WIDTH
+// EMIT_MIR rustc.main.SimplifyArmIdentity.diff
+// EMIT_MIR rustc.main.PreCodegen.diff
diff --git a/src/test/mir-opt/issue-73223/32bit/rustc.main.PreCodegen.diff b/src/test/mir-opt/issue-73223/32bit/rustc.main.PreCodegen.diff
new file mode 100644
index 00000000000..59c00e1b96f
--- /dev/null
+++ b/src/test/mir-opt/issue-73223/32bit/rustc.main.PreCodegen.diff
@@ -0,0 +1,252 @@
+- // MIR for `main` before PreCodegen
++ // MIR for `main` after PreCodegen
+  
+  fn main() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/issue-73223.rs:1:11: 1:11
+      let mut _1: std::option::Option<i32>; // in scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+      let _2: i32;                         // in scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+      let mut _4: i32;                     // in scope 0 at $DIR/issue-73223.rs:7:22: 7:27
+      let mut _5: (&i32, &i32);            // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _6: &i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _9: bool;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _10: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _11: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _12: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _13: &std::fmt::Arguments;       // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _14: std::fmt::Arguments;        // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _15: &[&str];                // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _16: &[std::fmt::ArgumentV1]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _17: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _18: [std::fmt::ArgumentV1; 2];  // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _19: (&&i32, &&i32);         // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _20: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _21: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _22: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _23: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _26: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _27: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _28: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _29: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      scope 1 {
+          debug split => _2;               // in scope 1 at $DIR/issue-73223.rs:2:9: 2:14
+          let _3: std::option::Option<i32>; // in scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          scope 3 {
+              debug _prev => _3;           // in scope 3 at $DIR/issue-73223.rs:7:9: 7:14
+              let _7: &i32;                // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let _8: &i32;                // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              scope 4 {
+                  debug left_val => _7;    // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  debug right_val => _8;   // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _24: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _25: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  scope 5 {
+                      debug arg0 => _24;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      debug arg1 => _25;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      scope 6 {
+                          debug x => _24;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _27;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _30: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _31: &core::fmt::Opaque; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                      scope 8 {
+                          debug x => _25;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _29;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _32: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _33: &core::fmt::Opaque; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                  }
+                  scope 10 {
+                      debug pieces => _15; // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      debug args => _16;   // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      let mut _34: std::option::Option<&[std::fmt::rt::v1::Argument]>; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                  }
+              }
+          }
+      }
+      scope 2 {
+          debug v => _2;                   // in scope 2 at $DIR/issue-73223.rs:3:14: 3:15
+      }
+      scope 7 {
+      }
+      scope 9 {
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          ((_1 as Some).0: i32) = const 1_i32; // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+                                           // ty::Const
+                                           // + ty: i32
+                                           // + val: Value(Scalar(0x00000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:2:28: 2:29
+                                           // + literal: Const { ty: i32, val: Value(Scalar(0x00000001)) }
+          discriminant(_1) = 1;            // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          _2 = ((_1 as Some).0: i32);      // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
+          StorageLive(_3);                 // scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          StorageLive(_4);                 // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          _4 = _2;                         // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          ((_3 as Some).0: i32) = move _4; // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          discriminant(_3) = 1;            // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          StorageDead(_4);                 // scope 1 at $DIR/issue-73223.rs:7:27: 7:28
+          StorageLive(_5);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_6);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _6 = &_2;                        // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_5.0: &i32) = move _6;          // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_5.1: &i32) = const main::promoted[1]; // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &i32
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &i32, val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1])) }
+          StorageDead(_6);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_7);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _7 = (_5.0: &i32);               // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _8 = (_5.1: &i32);               // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_9);                 // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_10);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_11);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _11 = (*_7);                     // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_12);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _12 = (*_8);                     // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _10 = Eq(move _11, move _12);    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_12);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_11);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _9 = Not(move _10);              // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_10);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          switchInt(_9) -> [false: bb1, otherwise: bb2]; // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      }
+  
+      bb1: {
+          StorageDead(_9);                 // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_7);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_5);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:1:11: 9:2
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          StorageDead(_3);                 // scope 1 at $DIR/issue-73223.rs:9:1: 9:2
+          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
+      }
+  
+      bb2: {
+          StorageLive(_14);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _15 = const main::promoted[0] as &[&str] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &[&str; 3]
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &[&str; 3], val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0])) }
+          StorageLive(_18);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_19);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_20);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_21);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _21 = _7;                        // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _20 = &_21;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_22);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_23);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _23 = _8;                        // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _22 = &_23;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_19.0: &&i32) = move _20;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          (_19.1: &&i32) = move _22;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_22);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_20);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _24 = (_19.0: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _25 = (_19.1: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_26);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _27 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_30);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _30 = const 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>>(move _27) -> bb3; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb3: {
+          StorageLive(_31);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _31 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _24) -> bb4; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb4: {
+          (_26.0: &core::fmt::Opaque) = move _31; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_26.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _30; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_31);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_30);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_28);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _29 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_32);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _32 = const 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>>(move _29) -> bb5; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb5: {
+          StorageLive(_33);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _33 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _25) -> bb6; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb6: {
+          (_28.0: &core::fmt::Opaque) = move _33; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_28.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _32; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_33);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_32);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _18 = [move _26, move _28];      // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_28);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_26);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _17 = &_18;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _16 = move _17 as &[std::fmt::ArgumentV1] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_34);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          discriminant(_34) = 0;           // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.0: &[&str]) = move _15;     // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.1: std::option::Option<&[std::fmt::rt::v1::Argument]>) = move _34; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.2: &[std::fmt::ArgumentV1]) = move _16; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_34);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _13 = &_14;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          const std::rt::begin_panic_fmt(move _13); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}, val: Value(Scalar(<ZST>)) }
+      }
+  }
+  
diff --git a/src/test/mir-opt/issue-73223/32bit/rustc.main.SimplifyArmIdentity.diff b/src/test/mir-opt/issue-73223/32bit/rustc.main.SimplifyArmIdentity.diff
new file mode 100644
index 00000000000..e5b4a032880
--- /dev/null
+++ b/src/test/mir-opt/issue-73223/32bit/rustc.main.SimplifyArmIdentity.diff
@@ -0,0 +1,376 @@
+- // MIR for `main` before SimplifyArmIdentity
++ // MIR for `main` after SimplifyArmIdentity
+  
+  fn main() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/issue-73223.rs:1:11: 1:11
+      let _1: i32;                         // in scope 0 at $DIR/issue-73223.rs:2:9: 2:14
+      let mut _2: std::option::Option<i32>; // in scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+      let mut _3: isize;                   // in scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+      let _4: i32;                         // in scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+      let mut _5: !;                       // in scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+      let mut _7: i32;                     // in scope 0 at $DIR/issue-73223.rs:7:22: 7:27
+      let _8: ();                          // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _9: (&i32, &i32);            // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _10: &i32;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _11: &i32;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _12: i32;                        // in scope 0 at $DIR/issue-73223.rs:8:23: 8:24
+      let mut _15: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _16: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _17: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _18: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _19: !;                      // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _20: &std::fmt::Arguments;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _21: &std::fmt::Arguments;       // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _22: std::fmt::Arguments;        // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _23: &[&str];                // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _24: &[&str; 3];             // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _25: &[&str; 3];                 // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _26: [&str; 3];                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _27: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _28: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _29: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _30: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _31: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _32: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _33: &[std::fmt::ArgumentV1]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _34: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _35: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _36: [std::fmt::ArgumentV1; 2];  // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _37: (&&i32, &&i32);         // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _38: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _39: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _40: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _41: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _44: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _45: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _46: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _47: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _48: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _49: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      scope 1 {
+          debug split => _1;               // in scope 1 at $DIR/issue-73223.rs:2:9: 2:14
+          let _6: std::option::Option<i32>; // in scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          scope 3 {
+              debug _prev => _6;           // in scope 3 at $DIR/issue-73223.rs:7:9: 7:14
+              let _13: &i32;               // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let _14: &i32;               // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let mut _51: &i32;           // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              scope 4 {
+                  debug left_val => _13;   // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  debug right_val => _14;  // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _42: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _43: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let mut _50: &[&str; 3]; // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  scope 5 {
+                      debug arg0 => _42;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      debug arg1 => _43;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      scope 6 {
+                          debug x => _45;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _46;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _52: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _53: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _54: &core::fmt::Opaque; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _55: &&i32; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                      scope 8 {
+                          debug x => _48;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _49;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _56: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _57: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _58: &core::fmt::Opaque; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _59: &&i32; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                  }
+                  scope 10 {
+                      debug pieces => _23; // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      debug args => _33;   // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      let mut _60: &[&str]; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      let mut _61: std::option::Option<&[std::fmt::rt::v1::Argument]>; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      let mut _62: &[std::fmt::ArgumentV1]; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                  }
+              }
+          }
+      }
+      scope 2 {
+          debug v => _4;                   // in scope 2 at $DIR/issue-73223.rs:3:14: 3:15
+      }
+      scope 7 {
+      }
+      scope 9 {
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/issue-73223.rs:2:9: 2:14
+          StorageLive(_2);                 // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          ((_2 as Some).0: i32) = const 1_i32; // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+                                           // ty::Const
+                                           // + ty: i32
+                                           // + val: Value(Scalar(0x00000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:2:28: 2:29
+                                           // + literal: Const { ty: i32, val: Value(Scalar(0x00000001)) }
+          discriminant(_2) = 1;            // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          _3 = const 1_isize;              // scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+                                           // ty::Const
+                                           // + ty: isize
+                                           // + val: Value(Scalar(0x00000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:3:9: 3:16
+                                           // + literal: Const { ty: isize, val: Value(Scalar(0x00000001)) }
+          goto -> bb2;                     // scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+      }
+  
+      bb1: {
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:4:17: 4:23
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          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
+      }
+  
+      bb2: {
+          StorageLive(_4);                 // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          _4 = ((_2 as Some).0: i32);      // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          _1 = _4;                         // scope 2 at $DIR/issue-73223.rs:3:20: 3:21
+          StorageDead(_4);                 // scope 0 at $DIR/issue-73223.rs:3:21: 3:22
+          StorageDead(_2);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
+          StorageLive(_6);                 // scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          StorageLive(_7);                 // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          _7 = _1;                         // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          ((_6 as Some).0: i32) = move _7; // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          discriminant(_6) = 1;            // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          StorageDead(_7);                 // scope 1 at $DIR/issue-73223.rs:7:27: 7:28
+          StorageLive(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_9);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_10);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _10 = &_1;                       // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_11);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _51 = const main::promoted[1];   // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &i32
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &i32, val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1])) }
+          _11 = _51;                       // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_9.0: &i32) = move _10;         // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_9.1: &i32) = move _11;         // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_11);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_10);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_13);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _13 = (_9.0: &i32);              // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_14);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _14 = (_9.1: &i32);              // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_15);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_16);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_17);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _17 = (*_13);                    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_18);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _18 = (*_14);                    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _16 = Eq(move _17, move _18);    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_18);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_17);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _15 = Not(move _16);             // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_16);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          switchInt(_15) -> [false: bb4, otherwise: bb5]; // scope 4 at $SRC_DIR/libcore/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/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          StorageDead(_15);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_14);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_13);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_9);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:1:11: 9:2
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          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
+      }
+  
+      bb5: {
+          StorageLive(_19);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_20);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_21);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_22);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_23);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_24);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_25);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _50 = const main::promoted[0];   // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &[&str; 3]
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &[&str; 3], val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0])) }
+          _25 = _50;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _24 = _25;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _23 = move _24 as &[&str] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_24);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_33);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_34);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_35);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_36);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_37);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_38);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_39);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _39 = _13;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _38 = &_39;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_40);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_41);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _41 = _14;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _40 = &_41;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_37.0: &&i32) = move _38;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          (_37.1: &&i32) = move _40;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_40);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_38);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_42);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _42 = (_37.0: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_43);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _43 = (_37.1: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_44);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_45);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _45 = _42;                       // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_46);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _46 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_52);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_53);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _53 = _46;                       // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _52 = const 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>>(move _53) -> bb6; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_53);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_54);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_55);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _55 = _45;                       // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _54 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _55) -> bb7; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_55);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_44.0: &core::fmt::Opaque) = move _54; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_44.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _52; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_54);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_52);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_46);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_45);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_47);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_48);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _48 = _43;                       // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_49);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _49 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_56);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_57);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _57 = _49;                       // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _56 = const 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>>(move _57) -> bb8; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_57);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_58);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_59);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _59 = _48;                       // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _58 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _59) -> bb9; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_59);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_47.0: &core::fmt::Opaque) = move _58; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_47.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _56; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_58);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_56);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_49);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_48);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _36 = [move _44, move _47];      // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_47);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_44);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_43);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_42);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _35 = &_36;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _34 = _35;                       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _33 = move _34 as &[std::fmt::ArgumentV1] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_34);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_60);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _60 = _23;                       // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_61);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          discriminant(_61) = 0;           // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_62);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _62 = _33;                       // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.0: &[&str]) = move _60;     // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.1: std::option::Option<&[std::fmt::rt::v1::Argument]>) = move _61; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.2: &[std::fmt::ArgumentV1]) = move _62; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_62);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_61);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_60);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_33);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_23);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _21 = &_22;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _20 = _21;                       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          const std::rt::begin_panic_fmt(move _20); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}, val: Value(Scalar(<ZST>)) }
+      }
+  }
+  
diff --git a/src/test/mir-opt/issue-73223/64bit/rustc.main.PreCodegen.diff b/src/test/mir-opt/issue-73223/64bit/rustc.main.PreCodegen.diff
new file mode 100644
index 00000000000..59c00e1b96f
--- /dev/null
+++ b/src/test/mir-opt/issue-73223/64bit/rustc.main.PreCodegen.diff
@@ -0,0 +1,252 @@
+- // MIR for `main` before PreCodegen
++ // MIR for `main` after PreCodegen
+  
+  fn main() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/issue-73223.rs:1:11: 1:11
+      let mut _1: std::option::Option<i32>; // in scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+      let _2: i32;                         // in scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+      let mut _4: i32;                     // in scope 0 at $DIR/issue-73223.rs:7:22: 7:27
+      let mut _5: (&i32, &i32);            // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _6: &i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _9: bool;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _10: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _11: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _12: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _13: &std::fmt::Arguments;       // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _14: std::fmt::Arguments;        // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _15: &[&str];                // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _16: &[std::fmt::ArgumentV1]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _17: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _18: [std::fmt::ArgumentV1; 2];  // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _19: (&&i32, &&i32);         // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _20: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _21: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _22: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _23: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _26: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _27: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _28: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _29: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      scope 1 {
+          debug split => _2;               // in scope 1 at $DIR/issue-73223.rs:2:9: 2:14
+          let _3: std::option::Option<i32>; // in scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          scope 3 {
+              debug _prev => _3;           // in scope 3 at $DIR/issue-73223.rs:7:9: 7:14
+              let _7: &i32;                // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let _8: &i32;                // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              scope 4 {
+                  debug left_val => _7;    // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  debug right_val => _8;   // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _24: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _25: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  scope 5 {
+                      debug arg0 => _24;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      debug arg1 => _25;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      scope 6 {
+                          debug x => _24;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _27;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _30: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _31: &core::fmt::Opaque; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                      scope 8 {
+                          debug x => _25;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _29;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _32: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _33: &core::fmt::Opaque; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                  }
+                  scope 10 {
+                      debug pieces => _15; // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      debug args => _16;   // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      let mut _34: std::option::Option<&[std::fmt::rt::v1::Argument]>; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                  }
+              }
+          }
+      }
+      scope 2 {
+          debug v => _2;                   // in scope 2 at $DIR/issue-73223.rs:3:14: 3:15
+      }
+      scope 7 {
+      }
+      scope 9 {
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          ((_1 as Some).0: i32) = const 1_i32; // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+                                           // ty::Const
+                                           // + ty: i32
+                                           // + val: Value(Scalar(0x00000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:2:28: 2:29
+                                           // + literal: Const { ty: i32, val: Value(Scalar(0x00000001)) }
+          discriminant(_1) = 1;            // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          _2 = ((_1 as Some).0: i32);      // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          StorageDead(_1);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
+          StorageLive(_3);                 // scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          StorageLive(_4);                 // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          _4 = _2;                         // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          ((_3 as Some).0: i32) = move _4; // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          discriminant(_3) = 1;            // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          StorageDead(_4);                 // scope 1 at $DIR/issue-73223.rs:7:27: 7:28
+          StorageLive(_5);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_6);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _6 = &_2;                        // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_5.0: &i32) = move _6;          // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_5.1: &i32) = const main::promoted[1]; // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &i32
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &i32, val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1])) }
+          StorageDead(_6);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_7);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _7 = (_5.0: &i32);               // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _8 = (_5.1: &i32);               // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_9);                 // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_10);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_11);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _11 = (*_7);                     // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_12);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _12 = (*_8);                     // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _10 = Eq(move _11, move _12);    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_12);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_11);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _9 = Not(move _10);              // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_10);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          switchInt(_9) -> [false: bb1, otherwise: bb2]; // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      }
+  
+      bb1: {
+          StorageDead(_9);                 // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_7);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_5);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:1:11: 9:2
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          StorageDead(_3);                 // scope 1 at $DIR/issue-73223.rs:9:1: 9:2
+          return;                          // scope 0 at $DIR/issue-73223.rs:9:2: 9:2
+      }
+  
+      bb2: {
+          StorageLive(_14);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _15 = const main::promoted[0] as &[&str] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &[&str; 3]
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &[&str; 3], val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0])) }
+          StorageLive(_18);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_19);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_20);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_21);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _21 = _7;                        // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _20 = &_21;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_22);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_23);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _23 = _8;                        // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _22 = &_23;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_19.0: &&i32) = move _20;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          (_19.1: &&i32) = move _22;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_22);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_20);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _24 = (_19.0: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _25 = (_19.1: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_26);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _27 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_30);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _30 = const 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>>(move _27) -> bb3; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb3: {
+          StorageLive(_31);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _31 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _24) -> bb4; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb4: {
+          (_26.0: &core::fmt::Opaque) = move _31; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_26.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _30; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_31);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_30);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_28);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _29 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_32);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _32 = const 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>>(move _29) -> bb5; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb5: {
+          StorageLive(_33);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _33 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _25) -> bb6; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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>)) }
+      }
+  
+      bb6: {
+          (_28.0: &core::fmt::Opaque) = move _33; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_28.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _32; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_33);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_32);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _18 = [move _26, move _28];      // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_28);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_26);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _17 = &_18;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _16 = move _17 as &[std::fmt::ArgumentV1] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_34);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          discriminant(_34) = 0;           // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.0: &[&str]) = move _15;     // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.1: std::option::Option<&[std::fmt::rt::v1::Argument]>) = move _34; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_14.2: &[std::fmt::ArgumentV1]) = move _16; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_34);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _13 = &_14;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          const std::rt::begin_panic_fmt(move _13); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}, val: Value(Scalar(<ZST>)) }
+      }
+  }
+  
diff --git a/src/test/mir-opt/issue-73223/64bit/rustc.main.SimplifyArmIdentity.diff b/src/test/mir-opt/issue-73223/64bit/rustc.main.SimplifyArmIdentity.diff
new file mode 100644
index 00000000000..0c2651dc3c6
--- /dev/null
+++ b/src/test/mir-opt/issue-73223/64bit/rustc.main.SimplifyArmIdentity.diff
@@ -0,0 +1,376 @@
+- // MIR for `main` before SimplifyArmIdentity
++ // MIR for `main` after SimplifyArmIdentity
+  
+  fn main() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/issue-73223.rs:1:11: 1:11
+      let _1: i32;                         // in scope 0 at $DIR/issue-73223.rs:2:9: 2:14
+      let mut _2: std::option::Option<i32>; // in scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+      let mut _3: isize;                   // in scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+      let _4: i32;                         // in scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+      let mut _5: !;                       // in scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+      let mut _7: i32;                     // in scope 0 at $DIR/issue-73223.rs:7:22: 7:27
+      let _8: ();                          // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _9: (&i32, &i32);            // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _10: &i32;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _11: &i32;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _12: i32;                        // in scope 0 at $DIR/issue-73223.rs:8:23: 8:24
+      let mut _15: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _16: bool;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _17: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _18: i32;                    // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _19: !;                      // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _20: &std::fmt::Arguments;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _21: &std::fmt::Arguments;       // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _22: std::fmt::Arguments;        // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _23: &[&str];                // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _24: &[&str; 3];             // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _25: &[&str; 3];                 // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _26: [&str; 3];                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _27: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _28: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _29: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _30: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _31: &str;                   // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _32: &str;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _33: &[std::fmt::ArgumentV1]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _34: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _35: &[std::fmt::ArgumentV1; 2]; // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let _36: [std::fmt::ArgumentV1; 2];  // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _37: (&&i32, &&i32);         // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _38: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _39: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _40: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let _41: &i32;                       // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _44: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _45: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _46: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _47: std::fmt::ArgumentV1;   // in scope 0 at $SRC_DIR/libstd/macros.rs:LL:COL
+      let mut _48: &&i32;                  // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      let mut _49: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 0 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+      scope 1 {
+          debug split => _1;               // in scope 1 at $DIR/issue-73223.rs:2:9: 2:14
+          let _6: std::option::Option<i32>; // in scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          scope 3 {
+              debug _prev => _6;           // in scope 3 at $DIR/issue-73223.rs:7:9: 7:14
+              let _13: &i32;               // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let _14: &i32;               // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              let mut _51: &i32;           // in scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+              scope 4 {
+                  debug left_val => _13;   // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  debug right_val => _14;  // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _42: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let _43: &&i32;          // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  let mut _50: &[&str; 3]; // in scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                  scope 5 {
+                      debug arg0 => _42;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      debug arg1 => _43;   // in scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                      scope 6 {
+                          debug x => _45;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _46;  // in scope 6 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _52: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _53: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _54: &core::fmt::Opaque; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _55: &&i32; // in scope 6 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                      scope 8 {
+                          debug x => _48;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          debug f => _49;  // in scope 8 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                          let mut _56: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _57: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _58: &core::fmt::Opaque; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                          let mut _59: &&i32; // in scope 8 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      }
+                  }
+                  scope 10 {
+                      debug pieces => _23; // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      debug args => _33;   // in scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                      let mut _60: &[&str]; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      let mut _61: std::option::Option<&[std::fmt::rt::v1::Argument]>; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                      let mut _62: &[std::fmt::ArgumentV1]; // in scope 10 at $SRC_DIR/libstd/macros.rs:LL:COL
+                  }
+              }
+          }
+      }
+      scope 2 {
+          debug v => _4;                   // in scope 2 at $DIR/issue-73223.rs:3:14: 3:15
+      }
+      scope 7 {
+      }
+      scope 9 {
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/issue-73223.rs:2:9: 2:14
+          StorageLive(_2);                 // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          ((_2 as Some).0: i32) = const 1_i32; // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+                                           // ty::Const
+                                           // + ty: i32
+                                           // + val: Value(Scalar(0x00000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:2:28: 2:29
+                                           // + literal: Const { ty: i32, val: Value(Scalar(0x00000001)) }
+          discriminant(_2) = 1;            // scope 0 at $DIR/issue-73223.rs:2:23: 2:30
+          _3 = const 1_isize;              // scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+                                           // ty::Const
+                                           // + ty: isize
+                                           // + val: Value(Scalar(0x0000000000000001))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:3:9: 3:16
+                                           // + literal: Const { ty: isize, val: Value(Scalar(0x0000000000000001)) }
+          goto -> bb2;                     // scope 0 at $DIR/issue-73223.rs:3:9: 3:16
+      }
+  
+      bb1: {
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:4:17: 4:23
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:4:17: 4:23
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          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
+      }
+  
+      bb2: {
+          StorageLive(_4);                 // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          _4 = ((_2 as Some).0: i32);      // scope 0 at $DIR/issue-73223.rs:3:14: 3:15
+          _1 = _4;                         // scope 2 at $DIR/issue-73223.rs:3:20: 3:21
+          StorageDead(_4);                 // scope 0 at $DIR/issue-73223.rs:3:21: 3:22
+          StorageDead(_2);                 // scope 0 at $DIR/issue-73223.rs:5:6: 5:7
+          StorageLive(_6);                 // scope 1 at $DIR/issue-73223.rs:7:9: 7:14
+          StorageLive(_7);                 // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          _7 = _1;                         // scope 1 at $DIR/issue-73223.rs:7:22: 7:27
+          ((_6 as Some).0: i32) = move _7; // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          discriminant(_6) = 1;            // scope 1 at $DIR/issue-73223.rs:7:17: 7:28
+          StorageDead(_7);                 // scope 1 at $DIR/issue-73223.rs:7:27: 7:28
+          StorageLive(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_9);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_10);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _10 = &_1;                       // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_11);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _51 = const main::promoted[1];   // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &i32
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &i32, val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[1])) }
+          _11 = _51;                       // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_9.0: &i32) = move _10;         // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_9.1: &i32) = move _11;         // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_11);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_10);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_13);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _13 = (_9.0: &i32);              // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_14);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _14 = (_9.1: &i32);              // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_15);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_16);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_17);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _17 = (*_13);                    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_18);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _18 = (*_14);                    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _16 = Eq(move _17, move _18);    // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_18);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_17);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _15 = Not(move _16);             // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_16);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          switchInt(_15) -> [false: bb4, otherwise: bb5]; // scope 4 at $SRC_DIR/libcore/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/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          StorageDead(_15);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_14);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_13);                // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_9);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_8);                 // scope 3 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _0 = const ();                   // scope 0 at $DIR/issue-73223.rs:1:11: 9:2
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/issue-73223.rs:1:11: 9:2
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          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
+      }
+  
+      bb5: {
+          StorageLive(_19);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_20);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_21);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_22);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_23);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_24);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_25);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _50 = const main::promoted[0];   // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: &[&str; 3]
+                                           // + val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0]))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: &[&str; 3], val: Unevaluated(DefId(0:3 ~ issue_73223[317d]::main[0]), [], Some(promoted[0])) }
+          _25 = _50;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _24 = _25;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _23 = move _24 as &[&str] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageDead(_24);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_33);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_34);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_35);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_36);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_37);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_38);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_39);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _39 = _13;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _38 = &_39;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_40);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_41);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _41 = _14;                       // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _40 = &_41;                      // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          (_37.0: &&i32) = move _38;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          (_37.1: &&i32) = move _40;       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_40);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_38);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_42);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _42 = (_37.0: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_43);                // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _43 = (_37.1: &&i32);            // scope 4 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_44);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_45);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _45 = _42;                       // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_46);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _46 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_52);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_53);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _53 = _46;                       // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _52 = const 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>>(move _53) -> bb6; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_53);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_54);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_55);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _55 = _45;                       // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _54 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _55) -> bb7; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_55);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_44.0: &core::fmt::Opaque) = move _54; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_44.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _52; // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_54);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_52);                // scope 7 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_46);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_45);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_47);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_48);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _48 = _43;                       // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          StorageLive(_49);                // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+          _49 = const <&i32 as std::fmt::Debug>::fmt as for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> (Pointer(ReifyFnPointer)); // scope 5 at $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's, 't0> fn(&'r &i32, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error> {<&i32 as std::fmt::Debug>::fmt}, val: Value(Scalar(<ZST>)) }
+          StorageLive(_56);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_57);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _57 = _49;                       // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _56 = const 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>>(move _57) -> bb8; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::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>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_57);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_58);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_59);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _59 = _48;                       // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _58 = const std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>(move _59) -> bb9; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: unsafe extern "rust-intrinsic" fn(&&i32) -> &core::fmt::Opaque {std::intrinsics::transmute::<&&i32, &core::fmt::Opaque>}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libcore/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: {
+          StorageDead(_59);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_47.0: &core::fmt::Opaque) = move _58; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_47.1: for<'r, 's, 't0> fn(&'r core::fmt::Opaque, &'s mut std::fmt::Formatter<'t0>) -> std::result::Result<(), std::fmt::Error>) = move _56; // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_58);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_56);                // scope 9 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_49);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_48);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _36 = [move _44, move _47];      // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_47);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_44);                // scope 5 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_43);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_42);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _35 = &_36;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _34 = _35;                       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _33 = move _34 as &[std::fmt::ArgumentV1] (Pointer(Unsize)); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_34);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageLive(_60);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _60 = _23;                       // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_61);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          discriminant(_61) = 0;           // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageLive(_62);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          _62 = _33;                       // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.0: &[&str]) = move _60;     // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.1: std::option::Option<&[std::fmt::rt::v1::Argument]>) = move _61; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          (_22.2: &[std::fmt::ArgumentV1]) = move _62; // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_62);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_61);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_60);                // scope 10 at $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+          StorageDead(_33);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          StorageDead(_23);                // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _21 = &_22;                      // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          _20 = _21;                       // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+          const std::rt::begin_panic_fmt(move _20); // scope 4 at $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/libstd/macros.rs:LL:COL
+                                           // + literal: Const { ty: for<'r, 's> fn(&'r std::fmt::Arguments<'s>) -> ! {std::rt::begin_panic_fmt}, val: Value(Scalar(<ZST>)) }
+      }
+  }
+  
diff --git a/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/32bit/rustc.map.SimplifyLocals.diff b/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/32bit/rustc.map.SimplifyLocals.diff
index f0b696118e9..551f6db08a5 100644
--- a/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/32bit/rustc.map.SimplifyLocals.diff
+++ b/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/32bit/rustc.map.SimplifyLocals.diff
@@ -5,12 +5,12 @@
       debug x => _1;                       // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:1:8: 1:9
       let mut _0: std::option::Option<std::boxed::Box<()>>; // return place in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:1:31: 1:46
       let mut _2: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:3:9: 3:13
-      let _3: std::boxed::Box<()>;         // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
+-     let _3: std::boxed::Box<()>;         // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
 -     let mut _4: std::boxed::Box<()>;     // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:25: 4:26
 -     let mut _5: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:6:1: 6:2
 -     let mut _6: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:6:1: 6:2
       scope 1 {
-          debug x => _3;                   // in scope 1 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
+          debug x => ((_0 as Some).0: std::boxed::Box<()>); // in scope 1 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
       }
   
       bb0: {
diff --git a/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/64bit/rustc.map.SimplifyLocals.diff b/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/64bit/rustc.map.SimplifyLocals.diff
index 1ac6eb85441..388b382b86d 100644
--- a/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/64bit/rustc.map.SimplifyLocals.diff
+++ b/src/test/mir-opt/simplify-locals-removes-unused-discriminant-reads/64bit/rustc.map.SimplifyLocals.diff
@@ -5,12 +5,12 @@
       debug x => _1;                       // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:1:8: 1:9
       let mut _0: std::option::Option<std::boxed::Box<()>>; // return place in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:1:31: 1:46
       let mut _2: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:3:9: 3:13
-      let _3: std::boxed::Box<()>;         // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
+-     let _3: std::boxed::Box<()>;         // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
 -     let mut _4: std::boxed::Box<()>;     // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:25: 4:26
 -     let mut _5: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:6:1: 6:2
 -     let mut _6: isize;                   // in scope 0 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:6:1: 6:2
       scope 1 {
-          debug x => _3;                   // in scope 1 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
+          debug x => ((_0 as Some).0: std::boxed::Box<()>); // in scope 1 at $DIR/simplify-locals-removes-unused-discriminant-reads.rs:4:14: 4:15
       }
   
       bb0: {
diff --git a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyArmIdentity.diff b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyArmIdentity.diff
index 7f8366309c0..e6d794a7150 100644
--- a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyArmIdentity.diff
+++ b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyArmIdentity.diff
@@ -15,22 +15,27 @@
       let _10: u32;                        // in scope 0 at $DIR/simplify_try.rs:6:13: 6:15
       let mut _11: u32;                    // in scope 0 at $DIR/simplify_try.rs:7:8: 7:9
       scope 1 {
-          debug y => _2;                   // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
+-         debug y => _2;                   // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
++         debug y => ((_0 as Ok).0: u32);  // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
       }
       scope 2 {
-          debug err => _6;                 // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
+-         debug err => _6;                 // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
++         debug err => ((_0 as Err).0: i32); // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
           scope 3 {
               scope 7 {
-                  debug t => _9;           // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+-                 debug t => _9;           // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
++                 debug t => ((_0 as Err).0: i32); // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
               }
               scope 8 {
-                  debug v => _8;           // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
+-                 debug v => _8;           // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
++                 debug v => ((_0 as Err).0: i32); // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
                   let mut _12: i32;        // in scope 8 at $DIR/simplify_try.rs:6:14: 6:15
               }
           }
       }
       scope 4 {
-          debug val => _10;                // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
+-         debug val => _10;                // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
++         debug val => ((_0 as Ok).0: u32); // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
           scope 5 {
           }
       }
diff --git a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyBranchSame.after.mir b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyBranchSame.after.mir
index be61e5e2a9f..24bde51c7d3 100644
--- a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyBranchSame.after.mir
+++ b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyBranchSame.after.mir
@@ -14,22 +14,22 @@ fn try_identity(_1: std::result::Result<u32, i32>) -> std::result::Result<u32, i
     let _10: u32;                        // in scope 0 at $DIR/simplify_try.rs:6:13: 6:15
     let mut _11: u32;                    // in scope 0 at $DIR/simplify_try.rs:7:8: 7:9
     scope 1 {
-        debug y => _2;                   // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
+        debug y => ((_0 as Ok).0: u32);  // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
     }
     scope 2 {
-        debug err => _6;                 // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
+        debug err => ((_0 as Err).0: i32); // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
         scope 3 {
             scope 7 {
-                debug t => _9;           // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+                debug t => ((_0 as Err).0: i32); // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
             }
             scope 8 {
-                debug v => _8;           // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
+                debug v => ((_0 as Err).0: i32); // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
                 let mut _12: i32;        // in scope 8 at $DIR/simplify_try.rs:6:14: 6:15
             }
         }
     }
     scope 4 {
-        debug val => _10;                // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
+        debug val => ((_0 as Ok).0: u32); // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
         scope 5 {
         }
     }
diff --git a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyLocals.after.mir b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyLocals.after.mir
index b12036f6a03..929f04d4654 100644
--- a/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyLocals.after.mir
+++ b/src/test/mir-opt/simplify_try/rustc.try_identity.SimplifyLocals.after.mir
@@ -3,27 +3,22 @@
 fn try_identity(_1: std::result::Result<u32, i32>) -> std::result::Result<u32, i32> {
     debug x => _1;                       // in scope 0 at $DIR/simplify_try.rs:5:17: 5:18
     let mut _0: std::result::Result<u32, i32>; // return place in scope 0 at $DIR/simplify_try.rs:5:41: 5:57
-    let _2: u32;                         // in scope 0 at $DIR/simplify_try.rs:6:9: 6:10
-    let _3: i32;                         // in scope 0 at $DIR/simplify_try.rs:6:14: 6:15
-    let mut _4: i32;                     // in scope 0 at $DIR/simplify_try.rs:6:14: 6:15
-    let mut _5: i32;                     // in scope 0 at $DIR/simplify_try.rs:6:14: 6:15
-    let _6: u32;                         // in scope 0 at $DIR/simplify_try.rs:6:13: 6:15
     scope 1 {
-        debug y => _2;                   // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
+        debug y => ((_0 as Ok).0: u32);  // in scope 1 at $DIR/simplify_try.rs:6:9: 6:10
     }
     scope 2 {
-        debug err => _3;                 // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
+        debug err => ((_0 as Err).0: i32); // in scope 2 at $DIR/simplify_try.rs:6:14: 6:15
         scope 3 {
             scope 7 {
-                debug t => _5;           // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+                debug t => ((_0 as Err).0: i32); // in scope 7 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
             }
             scope 8 {
-                debug v => _4;           // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
+                debug v => ((_0 as Err).0: i32); // in scope 8 at $SRC_DIR/libcore/result.rs:LL:COL
             }
         }
     }
     scope 4 {
-        debug val => _6;                 // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
+        debug val => ((_0 as Ok).0: u32); // in scope 4 at $DIR/simplify_try.rs:6:13: 6:15
         scope 5 {
         }
     }
@@ -32,9 +27,7 @@ fn try_identity(_1: std::result::Result<u32, i32>) -> std::result::Result<u32, i
     }
 
     bb0: {
-        StorageLive(_2);                 // scope 0 at $DIR/simplify_try.rs:6:9: 6:10
         _0 = move _1;                    // scope 1 at $DIR/simplify_try.rs:7:5: 7:10
-        StorageDead(_2);                 // scope 0 at $DIR/simplify_try.rs:8:1: 8:2
         return;                          // scope 0 at $DIR/simplify_try.rs:8:2: 8:2
     }
 }