Remove Ord from PlaceRef

Author: pierwill

compiler/rustc_const_eval/src/transform/validate.rs

@@ -1,5 +1,6 @@
 //! Validates the MIR to ensure that invariants are upheld.
 
+use rustc_data_structures::fx::FxIndexSet;
 use rustc_index::bit_set::BitSet;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::interpret::Scalar;
@@ -54,7 +55,7 @@ impl<'tcx> MirPass<'tcx> for Validator {
             mir_phase,
             reachable_blocks: traversal::reachable_as_bitset(body),
             storage_liveness,
-            place_cache: Vec::new(),
+            place_cache: FxIndexSet::default(),
         }
         .visit_body(body);
     }
@@ -108,7 +109,7 @@ struct TypeChecker<'a, 'tcx> {
     mir_phase: MirPhase,
     reachable_blocks: BitSet<BasicBlock>,
     storage_liveness: ResultsCursor<'a, 'tcx, MaybeStorageLive>,
-    place_cache: Vec<PlaceRef<'tcx>>,
+    place_cache: FxIndexSet<PlaceRef<'tcx>>,
 }
 
 impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
@@ -438,16 +439,14 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 // Currently this simply checks for duplicate places.
                 self.place_cache.clear();
                 if let Some((destination, _)) = destination {
-                    self.place_cache.push(destination.as_ref());
+                    self.place_cache.insert(destination.as_ref());
                 }
                 for arg in args {
                     if let Operand::Move(place) = arg {
-                        self.place_cache.push(place.as_ref());
+                        self.place_cache.insert(place.as_ref());
                     }
                 }
                 let all_len = self.place_cache.len();
-                self.place_cache.sort_unstable();
-                self.place_cache.dedup();
                 let has_duplicates = all_len != self.place_cache.len();
                 if has_duplicates {
                     self.fail(

compiler/rustc_middle/src/mir/mod.rs

@@ -1841,7 +1841,7 @@ rustc_index::newtype_index! {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct PlaceRef<'tcx> {
     pub local: Local,
     pub projection: &'tcx [PlaceElem<'tcx>],

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

@@ -10,6 +10,7 @@ use crate::build::scope::DropKind;
 use crate::build::ForGuard::{self, OutsideGuard, RefWithinGuard};
 use crate::build::{BlockAnd, BlockAndExtension, Builder};
 use crate::build::{GuardFrame, GuardFrameLocal, LocalsForNode};
+use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::{
     fx::{FxHashSet, FxIndexMap},
     stack::ensure_sufficient_stack,
@@ -1722,7 +1723,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         debug!("add_fake_borrows fake_borrows = {:?}", fake_borrows);
 
-        let mut all_fake_borrows = Vec::with_capacity(fake_borrows.len());
+        let mut all_fake_borrows = FxIndexSet::default();
 
         // Insert a Shallow borrow of the prefixes of any fake borrows.
         for place in fake_borrows {
@@ -1734,17 +1735,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     // Insert a shallow borrow after a deref. For other
                     // projections the borrow of prefix_cursor will
                     // conflict with any mutation of base.
-                    all_fake_borrows.push(PlaceRef { local: place.local, projection: proj_base });
+                    all_fake_borrows.insert(PlaceRef { local: place.local, projection: proj_base });
                 }
             }
 
-            all_fake_borrows.push(place.as_ref());
+            all_fake_borrows.insert(place.as_ref());
         }
 
-        // Deduplicate and ensure a deterministic order.
-        all_fake_borrows.sort();
-        all_fake_borrows.dedup();
-
         debug!("add_fake_borrows all_fake_borrows = {:?}", all_fake_borrows);
 
         all_fake_borrows