Fix SROA without deaggregation.

compiler/rustc_mir_transform/src/sroa.rs

@@ -2,6 +2,7 @@ use crate::MirPass;
 use rustc_data_structures::fx::{FxIndexMap, IndexEntry};
 use rustc_index::bit_set::BitSet;
 use rustc_index::vec::IndexVec;
+use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
@@ -13,7 +14,9 @@ impl<'tcx> MirPass<'tcx> for ScalarReplacementOfAggregates {
         sess.mir_opt_level() >= 3
     }
 
+    #[instrument(level = "debug", skip(self, tcx, body))]
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+        debug!(def_id = ?body.source.def_id());
         let escaping = escaping_locals(&*body);
         debug!(?escaping);
         let replacements = compute_flattening(tcx, body, escaping);
@@ -69,15 +72,28 @@ fn escaping_locals(body: &Body<'_>) -> BitSet<Local> {
             self.super_rvalue(rvalue, location)
         }
 
-        fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
+        fn visit_assign(
-            if let StatementKind::StorageLive(..)
+            &mut self,
-            | StatementKind::StorageDead(..)
+            lvalue: &Place<'tcx>,
-            | StatementKind::Deinit(..) = statement.kind
+            rvalue: &Rvalue<'tcx>,
-            {
+            location: Location,
-                // Storage statements are expanded in run_pass.
+        ) {
+            if lvalue.as_local().is_some() && let Rvalue::Aggregate(..) = rvalue {
+                // Aggregate assignments are expanded in run_pass.
+                self.visit_rvalue(rvalue, location);
                 return;
             }
-            self.super_statement(statement, location)
+            self.super_assign(lvalue, rvalue, location)
+        }
+
+        fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
+            match statement.kind {
+                // Storage statements are expanded in run_pass.
+                StatementKind::StorageLive(..)
+                | StatementKind::StorageDead(..)
+                | StatementKind::Deinit(..) => return,
+                _ => self.super_statement(statement, location),
+            }
         }
 
         fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
@@ -192,6 +208,7 @@ fn replace_flattened_locals<'tcx>(
         replacements,
         all_dead_locals,
         fragments,
+        patch: MirPatch::new(body),
     };
     for (bb, data) in body.basic_blocks.as_mut_preserves_cfg().iter_enumerated_mut() {
         visitor.visit_basic_block_data(bb, data);
@@ -205,6 +222,7 @@ fn replace_flattened_locals<'tcx>(
     for var_debug_info in &mut body.var_debug_info {
         visitor.visit_var_debug_info(var_debug_info);
     }
+    visitor.patch.apply(body);
 }
 
 struct ReplacementVisitor<'tcx, 'll> {
@@ -218,6 +236,7 @@ struct ReplacementVisitor<'tcx, 'll> {
     /// Pre-computed list of all "new" locals for each "old" local. This is used to expand storage
     /// and deinit statement and debuginfo.
     fragments: IndexVec<Local, Vec<(&'tcx [PlaceElem<'tcx>], Local)>>,
+    patch: MirPatch<'tcx>,
 }
 
 impl<'tcx, 'll> ReplacementVisitor<'tcx, 'll> {
@@ -255,12 +274,63 @@ impl<'tcx, 'll> MutVisitor<'tcx> for ReplacementVisitor<'tcx, 'll> {
     }
 
     fn visit_statement(&mut self, statement: &mut Statement<'tcx>, location: Location) {
-        if let StatementKind::StorageLive(..)
+        match statement.kind {
-        | StatementKind::StorageDead(..)
+            StatementKind::StorageLive(l) => {
-        | StatementKind::Deinit(..) = statement.kind
+                if self.all_dead_locals.contains(l) {
-        {
+                    let final_locals = &self.fragments[l];
-            // Storage statements are expanded in run_pass.
+                    for &(_, fl) in final_locals {
-            return;
+                        self.patch.add_statement(location, StatementKind::StorageLive(fl));
+                    }
+                    statement.make_nop();
+                }
+                return;
+            }
+            StatementKind::StorageDead(l) => {
+                if self.all_dead_locals.contains(l) {
+                    let final_locals = &self.fragments[l];
+                    for &(_, fl) in final_locals {
+                        self.patch.add_statement(location, StatementKind::StorageDead(fl));
+                    }
+                    statement.make_nop();
+                }
+                return;
+            }
+            StatementKind::Deinit(box ref place) => {
+                if let Some(local) = place.as_local()
+                    && self.all_dead_locals.contains(local)
+                {
+                    let final_locals = &self.fragments[local];
+                    for &(_, fl) in final_locals {
+                        self.patch.add_statement(
+                            location,
+                            StatementKind::Deinit(Box::new(fl.into())),
+                        );
+                    }
+                    statement.make_nop();
+                    return;
+                }
+            }
+
+            StatementKind::Assign(box (ref place, Rvalue::Aggregate(_, ref operands))) => {
+                if let Some(local) = place.as_local()
+                    && self.all_dead_locals.contains(local)
+                {
+                    let final_locals = &self.fragments[local];
+                    for &(projection, fl) in final_locals {
+                        let &[PlaceElem::Field(index, _)] = projection else { bug!() };
+                        let index = index.as_usize();
+                        let rvalue = Rvalue::Use(operands[index].clone());
+                        self.patch.add_statement(
+                            location,
+                            StatementKind::Assign(Box::new((fl.into(), rvalue))),
+                        );
+                    }
+                    statement.make_nop();
+                    return;
+                }
+            }
+
+            _ => {}
         }
         self.super_statement(statement, location)
     }
@@ -309,39 +379,6 @@ impl<'tcx, 'll> MutVisitor<'tcx> for ReplacementVisitor<'tcx, 'll> {
         }
     }
 
-    fn visit_basic_block_data(&mut self, bb: BasicBlock, bbdata: &mut BasicBlockData<'tcx>) {
-        self.super_basic_block_data(bb, bbdata);
-
-        #[derive(Debug)]
-        enum Stmt {
-            StorageLive,
-            StorageDead,
-            Deinit,
-        }
-
-        bbdata.expand_statements(|stmt| {
-            let source_info = stmt.source_info;
-            let (stmt, origin_local) = match &stmt.kind {
-                StatementKind::StorageLive(l) => (Stmt::StorageLive, *l),
-                StatementKind::StorageDead(l) => (Stmt::StorageDead, *l),
-                StatementKind::Deinit(p) if let Some(l) = p.as_local() => (Stmt::Deinit, l),
-                _ => return None,
-            };
-            if !self.all_dead_locals.contains(origin_local) {
-                return None;
-            }
-            let final_locals = self.fragments.get(origin_local)?;
-            Some(final_locals.iter().map(move |&(_, l)| {
-                let kind = match stmt {
-                    Stmt::StorageLive => StatementKind::StorageLive(l),
-                    Stmt::StorageDead => StatementKind::StorageDead(l),
-                    Stmt::Deinit => StatementKind::Deinit(Box::new(l.into())),
-                };
-                Statement { source_info, kind }
-            }))
-        });
-    }
-
     fn visit_local(&mut self, local: &mut Local, _: PlaceContext, _: Location) {
         assert!(!self.all_dead_locals.contains(*local));
     }

tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff

@@ -8,8 +8,8 @@
       let mut _6: u8;                      // in scope 0 at $DIR/const_debuginfo.rs:+4:15: +4:16
       let mut _7: u8;                      // in scope 0 at $DIR/const_debuginfo.rs:+4:19: +4:20
       let mut _8: u8;                      // in scope 0 at $DIR/const_debuginfo.rs:+4:23: +4:24
-      let mut _14: u32;                    // in scope 0 at $DIR/const_debuginfo.rs:+13:13: +13:16
+      let mut _13: u32;                    // in scope 0 at $DIR/const_debuginfo.rs:+13:13: +13:16
-      let mut _15: u32;                    // in scope 0 at $DIR/const_debuginfo.rs:+13:19: +13:22
+      let mut _14: u32;                    // in scope 0 at $DIR/const_debuginfo.rs:+13:19: +13:22
       scope 1 {
 -         debug x => _1;                   // in scope 1 at $DIR/const_debuginfo.rs:+1:9: +1:10
 +         debug x => const 1_u8;           // in scope 1 at $DIR/const_debuginfo.rs:+1:9: +1:10
@@ -35,12 +35,13 @@
                               let _11: std::option::Option<u16>; // in scope 6 at $DIR/const_debuginfo.rs:+10:9: +10:10
                               scope 7 {
                                   debug o => _11; // in scope 7 at $DIR/const_debuginfo.rs:+10:9: +10:10
-                                  let _12: Point; // in scope 7 at $DIR/const_debuginfo.rs:+12:9: +12:10
+                                  let _15: u32; // in scope 7 at $DIR/const_debuginfo.rs:+12:9: +12:10
+                                  let _16: u32; // in scope 7 at $DIR/const_debuginfo.rs:+12:9: +12:10
                                   scope 8 {
-                                      debug p => _12; // in scope 8 at $DIR/const_debuginfo.rs:+12:9: +12:10
+                                      debug p => Point{ .0 => _15, .1 => _16, }; // in scope 8 at $DIR/const_debuginfo.rs:+12:9: +12:10
-                                      let _13: u32; // in scope 8 at $DIR/const_debuginfo.rs:+13:9: +13:10
+                                      let _12: u32; // in scope 8 at $DIR/const_debuginfo.rs:+13:9: +13:10
                                       scope 9 {
--                                         debug a => _13; // in scope 9 at $DIR/const_debuginfo.rs:+13:9: +13:10
+-                                         debug a => _12; // in scope 9 at $DIR/const_debuginfo.rs:+13:9: +13:10
 +                                         debug a => const 64_u32; // in scope 9 at $DIR/const_debuginfo.rs:+13:9: +13:10
                                       }
                                   }
@@ -70,18 +71,11 @@
           _10 = (const true, const false, const 123_u32); // scope 5 at $DIR/const_debuginfo.rs:+8:13: +8:34
           StorageLive(_11);                // scope 6 at $DIR/const_debuginfo.rs:+10:9: +10:10
           _11 = Option::<u16>::Some(const 99_u16); // scope 6 at $DIR/const_debuginfo.rs:+10:13: +10:24
-          StorageLive(_12);                // scope 7 at $DIR/const_debuginfo.rs:+12:9: +12:10
+          _15 = const 32_u32;              // scope 7 at $DIR/const_debuginfo.rs:+12:13: +12:35
-          _12 = Point { x: const 32_u32, y: const 32_u32 }; // scope 7 at $DIR/const_debuginfo.rs:+12:13: +12:35
+          _16 = const 32_u32;              // scope 7 at $DIR/const_debuginfo.rs:+12:13: +12:35
-          StorageLive(_13);                // scope 8 at $DIR/const_debuginfo.rs:+13:9: +13:10
+          StorageLive(_12);                // scope 8 at $DIR/const_debuginfo.rs:+13:9: +13:10
-          StorageLive(_14);                // scope 8 at $DIR/const_debuginfo.rs:+13:13: +13:16
+          _12 = const 64_u32;              // scope 8 at $DIR/const_debuginfo.rs:+13:13: +13:22
-          _14 = const 32_u32;              // scope 8 at $DIR/const_debuginfo.rs:+13:13: +13:16
+          StorageDead(_12);                // scope 8 at $DIR/const_debuginfo.rs:+14:1: +14:2
-          StorageLive(_15);                // scope 8 at $DIR/const_debuginfo.rs:+13:19: +13:22
-          _15 = const 32_u32;              // scope 8 at $DIR/const_debuginfo.rs:+13:19: +13:22
-          _13 = const 64_u32;              // scope 8 at $DIR/const_debuginfo.rs:+13:13: +13:22
-          StorageDead(_15);                // scope 8 at $DIR/const_debuginfo.rs:+13:21: +13:22
-          StorageDead(_14);                // scope 8 at $DIR/const_debuginfo.rs:+13:21: +13:22
-          StorageDead(_13);                // scope 8 at $DIR/const_debuginfo.rs:+14:1: +14:2
-          StorageDead(_12);                // scope 7 at $DIR/const_debuginfo.rs:+14:1: +14:2
           StorageDead(_11);                // scope 6 at $DIR/const_debuginfo.rs:+14:1: +14:2
           StorageDead(_10);                // scope 5 at $DIR/const_debuginfo.rs:+14:1: +14:2
           StorageDead(_9);                 // scope 4 at $DIR/const_debuginfo.rs:+14:1: +14:2

tests/mir-opt/const_prop/mutable_variable_unprop_assign.main.ConstProp.diff

@@ -4,18 +4,19 @@
   fn main() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/mutable_variable_unprop_assign.rs:+0:11: +0:11
       let _1: i32;                         // in scope 0 at $DIR/mutable_variable_unprop_assign.rs:+1:9: +1:10
-      let mut _3: i32;                     // in scope 0 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
+      let mut _2: i32;                     // in scope 0 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
       scope 1 {
           debug a => _1;                   // in scope 1 at $DIR/mutable_variable_unprop_assign.rs:+1:9: +1:10
-          let mut _2: (i32, i32);          // in scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
+          let mut _5: i32;                 // in scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
+          let mut _6: i32;                 // in scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
           scope 2 {
-              debug x => _2;               // in scope 2 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
+              debug x => (i32, i32){ .1 => _5, .0 => _6, }; // in scope 2 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
-              let _4: i32;                 // in scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
+              let _3: i32;                 // in scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
               scope 3 {
-                  debug y => _4;           // in scope 3 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
+                  debug y => _3;           // in scope 3 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
-                  let _5: i32;             // in scope 3 at $DIR/mutable_variable_unprop_assign.rs:+5:9: +5:10
+                  let _4: i32;             // in scope 3 at $DIR/mutable_variable_unprop_assign.rs:+5:9: +5:10
                   scope 4 {
-                      debug z => _5;       // in scope 4 at $DIR/mutable_variable_unprop_assign.rs:+5:9: +5:10
+                      debug z => _6;       // in scope 4 at $DIR/mutable_variable_unprop_assign.rs:+5:9: +5:10
                   }
               }
           }
@@ -30,21 +31,17 @@
       }
   
       bb1: {
-          StorageLive(_2);                 // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
+          StorageLive(_5);                 // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:9: +2:14
--         _2 = (const 1_i32, const 2_i32); // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:29: +2:35
+          _5 = const 2_i32;                // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:29: +2:35
-+         _2 = const (1_i32, 2_i32);       // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:29: +2:35
+          _6 = const 1_i32;                // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+2:29: +2:35
-          StorageLive(_3);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
+          StorageLive(_2);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
-          _3 = _1;                         // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
+          _2 = _1;                         // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
-          (_2.1: i32) = move _3;           // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:5: +3:12
+          _5 = move _2;                    // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:5: +3:12
-          StorageDead(_3);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
+          StorageDead(_2);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+3:11: +3:12
-          StorageLive(_4);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
+          StorageLive(_3);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:9: +4:10
-          _4 = (_2.1: i32);                // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:13: +4:16
+          _3 = _5;                         // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+4:13: +4:16
-          StorageLive(_5);                 // scope 3 at $DIR/mutable_variable_unprop_assign.rs:+5:9: +5:10
+          StorageDead(_3);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
--         _5 = (_2.0: i32);                // scope 3 at $DIR/mutable_variable_unprop_assign.rs:+5:13: +5:16
+          StorageDead(_5);                 // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
-+         _5 = const 1_i32;                // scope 3 at $DIR/mutable_variable_unprop_assign.rs:+5:13: +5:16
-          StorageDead(_5);                 // scope 3 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
-          StorageDead(_4);                 // scope 2 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
-          StorageDead(_2);                 // scope 1 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
           StorageDead(_1);                 // scope 0 at $DIR/mutable_variable_unprop_assign.rs:+6:1: +6:2
           return;                          // scope 0 at $DIR/mutable_variable_unprop_assign.rs:+6:2: +6:2
       }

tests/mir-opt/const_prop/optimizes_into_variable.main.ConstProp.64bit.diff

@@ -9,7 +9,7 @@
       let _5: usize;                       // in scope 0 at $DIR/optimizes_into_variable.rs:+2:32: +2:33
       let mut _6: usize;                   // in scope 0 at $DIR/optimizes_into_variable.rs:+2:13: +2:34
       let mut _7: bool;                    // in scope 0 at $DIR/optimizes_into_variable.rs:+2:13: +2:34
-      let mut _9: Point;                   // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
+      let mut _9: u32;                     // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
       scope 1 {
           debug x => _1;                   // in scope 1 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
           let _3: i32;                     // in scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
@@ -17,7 +17,7 @@
               debug y => _3;               // in scope 2 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
               let _8: u32;                 // in scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
               scope 3 {
-                  debug z => _8;           // in scope 3 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
+                  debug z => _9;           // in scope 3 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
               }
           }
       }
@@ -50,13 +50,7 @@
 +         _3 = const 3_i32;                // scope 1 at $DIR/optimizes_into_variable.rs:+2:13: +2:34
           StorageDead(_5);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:34: +2:35
           StorageDead(_4);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:34: +2:35
-          StorageLive(_8);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
+          _9 = const 42_u32;               // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
-          StorageLive(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
-          _9 = Point { x: const 12_u32, y: const 42_u32 }; // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
--         _8 = (_9.1: u32);                // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:38
-+         _8 = const 42_u32;               // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:38
-          StorageDead(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:38: +3:39
-          StorageDead(_8);                 // scope 2 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
           StorageDead(_3);                 // scope 1 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
           StorageDead(_1);                 // scope 0 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
           return;                          // scope 0 at $DIR/optimizes_into_variable.rs:+4:2: +4:2

tests/mir-opt/const_prop/optimizes_into_variable.main.PreCodegen.after.64bit.mir

@@ -3,12 +3,12 @@
 fn main() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/optimizes_into_variable.rs:+0:11: +0:11
     let _1: i32;                         // in scope 0 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
+    let mut _3: u32;                     // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
     scope 1 {
         debug x => _1;                   // in scope 1 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
         let _2: i32;                     // in scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
         scope 2 {
             debug y => _2;               // in scope 2 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
-            let _3: u32;                 // in scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
             scope 3 {
                 debug z => _3;           // in scope 3 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
             }
@@ -18,8 +18,6 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
         StorageLive(_2);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
-        StorageLive(_3);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
-        StorageDead(_3);                 // scope 2 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         StorageDead(_2);                 // scope 1 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         StorageDead(_1);                 // scope 0 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         return;                          // scope 0 at $DIR/optimizes_into_variable.rs:+4:2: +4:2

tests/mir-opt/const_prop/optimizes_into_variable.main.ScalarReplacementOfAggregates.64bit.diff

@@ -10,6 +10,7 @@
       let mut _6: usize;                   // in scope 0 at $DIR/optimizes_into_variable.rs:+2:13: +2:34
       let mut _7: bool;                    // in scope 0 at $DIR/optimizes_into_variable.rs:+2:13: +2:34
       let mut _9: Point;                   // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
++     let mut _10: u32;                    // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
       scope 1 {
           debug x => _1;                   // in scope 1 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
           let _3: i32;                     // in scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
@@ -45,10 +46,17 @@
           StorageDead(_5);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:34: +2:35
           StorageDead(_4);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:34: +2:35
           StorageLive(_8);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
-          StorageLive(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
+-         StorageLive(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
-          _9 = Point { x: const 12_u32, y: const 42_u32 }; // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
+-         _9 = Point { x: const 12_u32, y: const 42_u32 }; // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
-          _8 = (_9.1: u32);                // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:38
+-         _8 = (_9.1: u32);                // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:38
-          StorageDead(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:38: +3:39
+-         StorageDead(_9);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:38: +3:39
++         StorageLive(_10);                // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
++         nop;                             // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
++         _10 = const 42_u32;              // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
++         nop;                             // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
++         _8 = _10;                        // scope 2 at $DIR/optimizes_into_variable.rs:+3:13: +3:38
++         StorageDead(_10);                // scope 2 at $DIR/optimizes_into_variable.rs:+3:38: +3:39
++         nop;                             // scope 2 at $DIR/optimizes_into_variable.rs:+3:38: +3:39
           nop;                             // scope 0 at $DIR/optimizes_into_variable.rs:+0:11: +4:2
           StorageDead(_8);                 // scope 2 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
           StorageDead(_3);                 // scope 1 at $DIR/optimizes_into_variable.rs:+4:1: +4:2

tests/mir-opt/const_prop/optimizes_into_variable.main.SimplifyLocals-final.after.64bit.mir

@@ -3,12 +3,12 @@
 fn main() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/optimizes_into_variable.rs:+0:11: +0:11
     let _1: i32;                         // in scope 0 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
+    let mut _3: u32;                     // in scope 0 at $DIR/optimizes_into_variable.rs:+3:13: +3:36
     scope 1 {
         debug x => _1;                   // in scope 1 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
         let _2: i32;                     // in scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
         scope 2 {
             debug y => _2;               // in scope 2 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
-            let _3: u32;                 // in scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
             scope 3 {
                 debug z => _3;           // in scope 3 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
             }
@@ -18,8 +18,6 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/optimizes_into_variable.rs:+1:9: +1:10
         StorageLive(_2);                 // scope 1 at $DIR/optimizes_into_variable.rs:+2:9: +2:10
-        StorageLive(_3);                 // scope 2 at $DIR/optimizes_into_variable.rs:+3:9: +3:10
-        StorageDead(_3);                 // scope 2 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         StorageDead(_2);                 // scope 1 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         StorageDead(_1);                 // scope 0 at $DIR/optimizes_into_variable.rs:+4:1: +4:2
         return;                          // scope 0 at $DIR/optimizes_into_variable.rs:+4:2: +4:2

tests/mir-opt/simple_option_map_e2e.ezmap.PreCodegen.after.mir

@@ -4,25 +4,22 @@ fn ezmap(_1: Option<i32>) -> Option<i32> {
     debug x => _1;                       // in scope 0 at $DIR/simple_option_map_e2e.rs:+0:14: +0:15
     let mut _0: std::option::Option<i32>; // return place in scope 0 at $DIR/simple_option_map_e2e.rs:+0:33: +0:44
     let mut _2: [closure@$DIR/simple_option_map_e2e.rs:14:12: 14:15]; // in scope 0 at $DIR/simple_option_map_e2e.rs:+1:12: +1:21
-    let mut _7: i32;                     // in scope 0 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
     scope 1 (inlined map::<i32, i32, [closure@$DIR/simple_option_map_e2e.rs:14:12: 14:15]>) { // at $DIR/simple_option_map_e2e.rs:14:5: 14:22
         debug slf => _1;                 // in scope 1 at $DIR/simple_option_map_e2e.rs:2:17: 2:20
         debug f => _2;                   // in scope 1 at $DIR/simple_option_map_e2e.rs:2:33: 2:34
         let mut _3: isize;               // in scope 1 at $DIR/simple_option_map_e2e.rs:7:9: 7:16
         let _4: i32;                     // in scope 1 at $DIR/simple_option_map_e2e.rs:7:14: 7:15
         let mut _5: i32;                 // in scope 1 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        let mut _6: (i32,);              // in scope 1 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
         scope 2 {
             debug x => _4;               // in scope 2 at $DIR/simple_option_map_e2e.rs:7:14: 7:15
             scope 3 (inlined ezmap::{closure#0}) { // at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-                debug n => _7;           // in scope 3 at $DIR/simple_option_map_e2e.rs:+1:13: +1:14
+                debug n => _4;           // in scope 3 at $DIR/simple_option_map_e2e.rs:+1:13: +1:14
             }
         }
     }
 
     bb0: {
         StorageLive(_2);                 // scope 0 at $DIR/simple_option_map_e2e.rs:+1:12: +1:21
-        StorageLive(_4);                 // scope 0 at $DIR/simple_option_map_e2e.rs:+1:5: +1:22
         _3 = discriminant(_1);           // scope 1 at $DIR/simple_option_map_e2e.rs:6:11: 6:14
         switchInt(move _3) -> [0: bb1, 1: bb3, otherwise: bb2]; // scope 1 at $DIR/simple_option_map_e2e.rs:6:5: 6:14
     }
@@ -39,20 +36,13 @@ fn ezmap(_1: Option<i32>) -> Option<i32> {
     bb3: {
         _4 = move ((_1 as Some).0: i32); // scope 1 at $DIR/simple_option_map_e2e.rs:7:14: 7:15
         StorageLive(_5);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        StorageLive(_6);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
+        _5 = Add(_4, const 1_i32);       // scope 3 at $DIR/simple_option_map_e2e.rs:+1:16: +1:21
-        _6 = (move _4,);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        StorageLive(_7);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        _7 = move (_6.0: i32);           // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        _5 = Add(_7, const 1_i32);       // scope 3 at $DIR/simple_option_map_e2e.rs:+1:16: +1:21
-        StorageDead(_7);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        StorageDead(_6);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:28: 7:29
         _0 = Option::<i32>::Some(move _5); // scope 2 at $DIR/simple_option_map_e2e.rs:7:20: 7:30
         StorageDead(_5);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:29: 7:30
         goto -> bb4;                     // scope 1 at $DIR/simple_option_map_e2e.rs:10:1: 10:2
     }
 
     bb4: {
-        StorageDead(_4);                 // scope 0 at $DIR/simple_option_map_e2e.rs:+1:5: +1:22
         StorageDead(_2);                 // scope 0 at $DIR/simple_option_map_e2e.rs:+1:21: +1:22
         return;                          // scope 0 at $DIR/simple_option_map_e2e.rs:+2:2: +2:2
     }

tests/mir-opt/sroa.flat.ScalarReplacementOfAggregates.diff

@@ -10,6 +10,10 @@
       let mut _5: Foo;                     // in scope 0 at $DIR/sroa.rs:+1:30: +1:70
       let mut _6: ();                      // in scope 0 at $DIR/sroa.rs:+1:45: +1:47
       let mut _7: std::option::Option<isize>; // in scope 0 at $DIR/sroa.rs:+1:60: +1:68
++     let mut _8: u8;                      // in scope 0 at $DIR/sroa.rs:+1:30: +1:70
++     let mut _9: ();                      // in scope 0 at $DIR/sroa.rs:+1:30: +1:70
++     let mut _10: &str;                   // in scope 0 at $DIR/sroa.rs:+1:30: +1:70
++     let mut _11: std::option::Option<isize>; // in scope 0 at $DIR/sroa.rs:+1:30: +1:70
       scope 1 {
           debug a => _1;                   // in scope 1 at $DIR/sroa.rs:+1:15: +1:16
           debug b => _2;                   // in scope 1 at $DIR/sroa.rs:+1:18: +1:19
@@ -26,26 +30,45 @@
       }
   
       bb0: {
-          StorageLive(_5);                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
+-         StorageLive(_5);                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         StorageLive(_8);                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         StorageLive(_9);                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         StorageLive(_10);                // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         StorageLive(_11);                // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         nop;                             // scope 0 at $DIR/sroa.rs:+1:30: +1:70
           StorageLive(_6);                 // scope 0 at $DIR/sroa.rs:+1:45: +1:47
           _6 = ();                         // scope 0 at $DIR/sroa.rs:+1:45: +1:47
           StorageLive(_7);                 // scope 0 at $DIR/sroa.rs:+1:60: +1:68
           _7 = Option::<isize>::Some(const -4_isize); // scope 0 at $DIR/sroa.rs:+1:60: +1:68
-          _5 = Foo { a: const 5_u8, b: move _6, c: const "a", d: move _7 }; // scope 0 at $DIR/sroa.rs:+1:30: +1:70
+-         _5 = Foo { a: const 5_u8, b: move _6, c: const "a", d: move _7 }; // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         _8 = const 5_u8;                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         _9 = move _6;                    // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         _10 = const "a";                 // scope 0 at $DIR/sroa.rs:+1:30: +1:70
                                            // mir::Constant
                                            // + span: $DIR/sroa.rs:57:52: 57:55
                                            // + literal: Const { ty: &str, val: Value(Slice(..)) }
++         _11 = move _7;                   // scope 0 at $DIR/sroa.rs:+1:30: +1:70
++         nop;                             // scope 0 at $DIR/sroa.rs:+1:30: +1:70
           StorageDead(_7);                 // scope 0 at $DIR/sroa.rs:+1:69: +1:70
           StorageDead(_6);                 // scope 0 at $DIR/sroa.rs:+1:69: +1:70
           StorageLive(_1);                 // scope 0 at $DIR/sroa.rs:+1:15: +1:16
-          _1 = (_5.0: u8);                 // scope 0 at $DIR/sroa.rs:+1:15: +1:16
+-         _1 = (_5.0: u8);                 // scope 0 at $DIR/sroa.rs:+1:15: +1:16
++         _1 = _8;                         // scope 0 at $DIR/sroa.rs:+1:15: +1:16
           StorageLive(_2);                 // scope 0 at $DIR/sroa.rs:+1:18: +1:19
-          _2 = (_5.1: ());                 // scope 0 at $DIR/sroa.rs:+1:18: +1:19
+-         _2 = (_5.1: ());                 // scope 0 at $DIR/sroa.rs:+1:18: +1:19
++         _2 = _9;                         // scope 0 at $DIR/sroa.rs:+1:18: +1:19
           StorageLive(_3);                 // scope 0 at $DIR/sroa.rs:+1:21: +1:22
-          _3 = (_5.2: &str);               // scope 0 at $DIR/sroa.rs:+1:21: +1:22
+-         _3 = (_5.2: &str);               // scope 0 at $DIR/sroa.rs:+1:21: +1:22
++         _3 = _10;                        // scope 0 at $DIR/sroa.rs:+1:21: +1:22
           StorageLive(_4);                 // scope 0 at $DIR/sroa.rs:+1:24: +1:25
-          _4 = (_5.3: std::option::Option<isize>); // scope 0 at $DIR/sroa.rs:+1:24: +1:25
+-         _4 = (_5.3: std::option::Option<isize>); // scope 0 at $DIR/sroa.rs:+1:24: +1:25
-          StorageDead(_5);                 // scope 0 at $DIR/sroa.rs:+1:70: +1:71
+-         StorageDead(_5);                 // scope 0 at $DIR/sroa.rs:+1:70: +1:71
++         _4 = _11;                        // scope 0 at $DIR/sroa.rs:+1:24: +1:25
++         StorageDead(_8);                 // scope 0 at $DIR/sroa.rs:+1:70: +1:71
++         StorageDead(_9);                 // scope 0 at $DIR/sroa.rs:+1:70: +1:71
++         StorageDead(_10);                // scope 0 at $DIR/sroa.rs:+1:70: +1:71
++         StorageDead(_11);                // scope 0 at $DIR/sroa.rs:+1:70: +1:71
++         nop;                             // scope 0 at $DIR/sroa.rs:+1:70: +1:71
           _0 = const ();                   // scope 0 at $DIR/sroa.rs:+0:15: +6:2
           StorageDead(_4);                 // scope 0 at $DIR/sroa.rs:+6:1: +6:2
           StorageDead(_3);                 // scope 0 at $DIR/sroa.rs:+6:1: +6:2

tests/mir-opt/sroa.structs.ScalarReplacementOfAggregates.diff

@@ -6,15 +6,23 @@
       let mut _0: f32;                     // return place in scope 0 at $DIR/sroa.rs:+0:27: +0:30
       let mut _2: structs::U;              // in scope 0 at $DIR/sroa.rs:+6:5: +6:21
       let mut _3: f32;                     // in scope 0 at $DIR/sroa.rs:+6:18: +6:19
++     let mut _4: f32;                     // in scope 0 at $DIR/sroa.rs:+6:5: +6:21
   
       bb0: {
-          StorageLive(_2);                 // scope 0 at $DIR/sroa.rs:+6:5: +6:21
+-         StorageLive(_2);                 // scope 0 at $DIR/sroa.rs:+6:5: +6:21
++         StorageLive(_4);                 // scope 0 at $DIR/sroa.rs:+6:5: +6:21
++         nop;                             // scope 0 at $DIR/sroa.rs:+6:5: +6:21
           StorageLive(_3);                 // scope 0 at $DIR/sroa.rs:+6:18: +6:19
           _3 = _1;                         // scope 0 at $DIR/sroa.rs:+6:18: +6:19
-          _2 = U { _foo: const 0_usize, a: move _3 }; // scope 0 at $DIR/sroa.rs:+6:5: +6:21
+-         _2 = U { _foo: const 0_usize, a: move _3 }; // scope 0 at $DIR/sroa.rs:+6:5: +6:21
++         _4 = move _3;                    // scope 0 at $DIR/sroa.rs:+6:5: +6:21
++         nop;                             // scope 0 at $DIR/sroa.rs:+6:5: +6:21
           StorageDead(_3);                 // scope 0 at $DIR/sroa.rs:+6:20: +6:21
-          _0 = (_2.1: f32);                // scope 0 at $DIR/sroa.rs:+6:5: +6:23
+-         _0 = (_2.1: f32);                // scope 0 at $DIR/sroa.rs:+6:5: +6:23
-          StorageDead(_2);                 // scope 0 at $DIR/sroa.rs:+7:1: +7:2
+-         StorageDead(_2);                 // scope 0 at $DIR/sroa.rs:+7:1: +7:2
++         _0 = _4;                         // scope 0 at $DIR/sroa.rs:+6:5: +6:23
++         StorageDead(_4);                 // scope 0 at $DIR/sroa.rs:+7:1: +7:2
++         nop;                             // scope 0 at $DIR/sroa.rs:+7:1: +7:2
           return;                          // scope 0 at $DIR/sroa.rs:+7:2: +7:2
       }
   }