Auto merge of #54526 - nnethercote:shrink-StatementKind, r=<try>

Shrink `StatementKind`

`StatementKind` occurs in significant amounts in Massif profiles.

Author: bors

src/librustc/mir/mod.rs

@@ -1610,7 +1610,7 @@ impl<'tcx> Statement<'tcx> {
 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
 pub enum StatementKind<'tcx> {
     /// Write the RHS Rvalue to the LHS Place.
-    Assign(Place<'tcx>, Rvalue<'tcx>),
+    Assign(Place<'tcx>, Box<Rvalue<'tcx>>),
 
     /// This represents all the reading that a pattern match may do
     /// (e.g. inspecting constants and discriminant values), and the
@@ -1633,8 +1633,8 @@ pub enum StatementKind<'tcx> {
     /// Execute a piece of inline Assembly.
     InlineAsm {
         asm: Box<InlineAsm>,
-        outputs: Vec<Place<'tcx>>,
-        inputs: Vec<Operand<'tcx>>,
+        outputs: Box<[Place<'tcx>]>,
+        inputs: Box<[Operand<'tcx>]>,
     },
 
     /// Assert the given places to be valid inhabitants of their type.  These statements are

src/librustc/ty/structural_impls.rs

@@ -720,6 +720,16 @@ impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Vec<T> {
     }
 }
 
+impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Box<[T]> {
+    fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
+        self.iter().map(|t| t.fold_with(folder)).collect::<Vec<_>>().into_boxed_slice()
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.iter().any(|t| t.visit_with(visitor))
+    }
+}
+
 impl<'tcx, T:TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::Binder<T> {
     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
         self.map_bound_ref(|ty| ty.fold_with(folder))

src/librustc_mir/borrow_check/error_reporting.rs

@@ -1221,7 +1221,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                     );
                     if let StatementKind::Assign(
                         Place::Local(assigned_to),
-                        rvalue,
+                        box rvalue,
                     ) = &stmt.kind {
                         debug!("annotate_argument_and_return_for_borrow: assigned_to={:?} \
                                rvalue={:?}", assigned_to, rvalue);
@@ -1725,7 +1725,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             None => return OtherUse(self.mir.source_info(location).span),
         };
 
-        if let StatementKind::Assign(_, Rvalue::Aggregate(ref kind, ref places)) = stmt.kind {
+        if let StatementKind::Assign(_, box Rvalue::Aggregate(ref kind, ref places)) = stmt.kind {
             if let AggregateKind::Closure(def_id, _) = **kind {
                 debug!("find_closure_move_span: found closure {:?}", places);
 
@@ -1788,7 +1788,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         }
 
         for stmt in &self.mir[location.block].statements[location.statement_index + 1..] {
-            if let StatementKind::Assign(_, Rvalue::Aggregate(ref kind, ref places)) = stmt.kind {
+            if let StatementKind::Assign(_, box Rvalue::Aggregate(ref kind, ref places))
+                = stmt.kind {
                 if let AggregateKind::Closure(def_id, _) = **kind {
                     debug!("find_closure_borrow_span: found closure {:?}", places);
 

src/librustc_mir/borrow_check/mod.rs

@@ -528,7 +528,7 @@ impl<'cx, 'gcx, 'tcx> DataflowResultsConsumer<'cx, 'tcx> for MirBorrowckCtxt<'cx
                 ref inputs,
             } => {
                 let context = ContextKind::InlineAsm.new(location);
-                for (o, output) in asm.outputs.iter().zip(outputs) {
+                for (o, output) in asm.outputs.iter().zip(outputs.iter()) {
                     if o.is_indirect {
                         // FIXME(eddyb) indirect inline asm outputs should
                         // be encoeded through MIR place derefs instead.
@@ -555,7 +555,7 @@ impl<'cx, 'gcx, 'tcx> DataflowResultsConsumer<'cx, 'tcx> for MirBorrowckCtxt<'cx
                         );
                     }
                 }
-                for input in inputs {
+                for input in inputs.iter() {
                     self.consume_operand(context, (input, span), flow_state);
                 }
             }

src/librustc_mir/borrow_check/move_errors.rs

@@ -100,7 +100,7 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
                 // flow could be used.
                 if let Some(StatementKind::Assign(
                     Place::Local(local),
-                    Rvalue::Use(Operand::Move(move_from)),
+                    box Rvalue::Use(Operand::Move(move_from)),
                 )) = self.mir.basic_blocks()[location.block]
                     .statements
                     .get(location.statement_index)

src/librustc_mir/borrow_check/nll/invalidation.rs

@@ -118,7 +118,7 @@ impl<'cg, 'cx, 'tcx, 'gcx> Visitor<'tcx> for InvalidationGenerator<'cg, 'cx, 'tc
                 ref inputs,
             } => {
                 let context = ContextKind::InlineAsm.new(location);
-                for (o, output) in asm.outputs.iter().zip(outputs) {
+                for (o, output) in asm.outputs.iter().zip(outputs.iter()) {
                     if o.is_indirect {
                         // FIXME(eddyb) indirect inline asm outputs should
                         // be encoeded through MIR place derefs instead.
@@ -137,7 +137,7 @@ impl<'cg, 'cx, 'tcx, 'gcx> Visitor<'tcx> for InvalidationGenerator<'cg, 'cx, 'tc
                         );
                     }
                 }
-                for input in inputs {
+                for input in inputs.iter() {
                     self.consume_operand(context, input);
                 }
             }

src/librustc_mir/build/cfg.rs

@@ -76,7 +76,7 @@ impl<'tcx> CFG<'tcx> {
                        rvalue: Rvalue<'tcx>) {
         self.push(block, Statement {
             source_info,
-            kind: StatementKind::Assign(place.clone(), rvalue)
+            kind: StatementKind::Assign(place.clone(), box rvalue)
         });
     }
 

src/librustc_mir/build/expr/stmt.rs

@@ -143,11 +143,13 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 let outputs = outputs
                     .into_iter()
                     .map(|output| unpack!(block = this.as_place(block, output)))
-                    .collect();
+                    .collect::<Vec<_>>()
+                    .into_boxed_slice();
                 let inputs = inputs
                     .into_iter()
                     .map(|input| unpack!(block = this.as_local_operand(block, input)))
-                    .collect();
+                    .collect::<Vec<_>>()
+                    .into_boxed_slice();
                 this.cfg.push(
                     block,
                     Statement {

src/librustc_mir/dataflow/impls/borrows.rs

@@ -270,7 +270,7 @@ impl<'a, 'gcx, 'tcx> BitDenotation for Borrows<'a, 'gcx, 'tcx> {
                 // re-consider the current implementations of the
                 // propagate_call_return method.
 
-                if let mir::Rvalue::Ref(region, _, ref place) = *rhs {
+                if let mir::Rvalue::Ref(region, _, ref place) = **rhs {
                     if place.ignore_borrow(
                         self.tcx,
                         self.mir,

src/librustc_mir/dataflow/move_paths/builder.rs

@@ -290,7 +290,7 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> {
                         self.gather_init(output, InitKind::Deep);
                     }
                 }
-                for input in inputs {
+                for input in inputs.iter() {
                     self.gather_operand(input);
                 }
             }