From 95eb5bcb67b97e7a1f3f6e6e68b3a8a0737ca24e Mon Sep 17 00:00:00 2001
From: Martin Nordholts <martin.nordholts@codetale.se>
Date: Wed, 3 Jan 2024 06:35:31 +0100
Subject: [PATCH] rustc_mir_transform: Make DestinationPropagation stable for
queries
By using FxIndexMap instead of FxHashMap, so that the order of visiting
of locals is deterministic.
We also need to bless
copy_propagation_arg.foo.DestinationPropagation.panic*.diff. Do not
review the diff of the diff. Instead look at the diff file before and
after this commit. Both before and after this commit, 3 statements are
replaced with nop. It's just that due to change in ordering, different
statements are replaced. But the net result is the same.
---
compiler/rustc_data_structures/src/fx.rs | 1 +
compiler/rustc_mir_transform/src/dest_prop.rs | 30 +++++++++----------
...oo.DestinationPropagation.panic-abort.diff | 18 +++++------
...o.DestinationPropagation.panic-unwind.diff | 18 +++++------
4 files changed, 33 insertions(+), 34 deletions(-)
diff --git a/compiler/rustc_data_structures/src/fx.rs b/compiler/rustc_data_structures/src/fx.rs
index 9fce0e1e65cc9..80e72250470c0 100644
--- a/compiler/rustc_data_structures/src/fx.rs
+++ b/compiler/rustc_data_structures/src/fx.rs
@@ -7,6 +7,7 @@ pub type StdEntry<'a, K, V> = std::collections::hash_map::Entry<'a, K, V>;
pub type FxIndexMap<K, V> = indexmap::IndexMap<K, V, BuildHasherDefault<FxHasher>>;
pub type FxIndexSet<V> = indexmap::IndexSet<V, BuildHasherDefault<FxHasher>>;
pub type IndexEntry<'a, K, V> = indexmap::map::Entry<'a, K, V>;
+pub type IndexOccupiedEntry<'a, K, V> = indexmap::map::OccupiedEntry<'a, K, V>;
#[macro_export]
macro_rules! define_id_collections {
diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs
index cd80f423466bc..49b0edc0db884 100644
--- a/compiler/rustc_mir_transform/src/dest_prop.rs
+++ b/compiler/rustc_mir_transform/src/dest_prop.rs
@@ -131,10 +131,8 @@
//! [attempt 2]: https://github.com/rust-lang/rust/pull/71003
//! [attempt 3]: https://github.com/rust-lang/rust/pull/72632
-use std::collections::hash_map::{Entry, OccupiedEntry};
-
use crate::MirPass;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::{FxIndexMap, IndexEntry, IndexOccupiedEntry};
use rustc_index::bit_set::BitSet;
use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor};
use rustc_middle::mir::HasLocalDecls;
@@ -211,7 +209,7 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
let mut merged_locals: BitSet<Local> = BitSet::new_empty(body.local_decls.len());
// This is the set of merges we will apply this round. It is a subset of the candidates.
- let mut merges = FxHashMap::default();
+ let mut merges = FxIndexMap::default();
for (src, candidates) in candidates.c.iter() {
if merged_locals.contains(*src) {
@@ -250,8 +248,8 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
/// frequently. Everything with a `&'alloc` lifetime points into here.
#[derive(Default)]
struct Allocations {
- candidates: FxHashMap<Local, Vec<Local>>,
- candidates_reverse: FxHashMap<Local, Vec<Local>>,
+ candidates: FxIndexMap<Local, Vec<Local>>,
+ candidates_reverse: FxIndexMap<Local, Vec<Local>>,
write_info: WriteInfo,
// PERF: Do this for `MaybeLiveLocals` allocations too.
}
@@ -272,11 +270,11 @@ struct Candidates<'alloc> {
///
/// We will still report that we would like to merge `_1` and `_2` in an attempt to allow us to
/// remove that assignment.
- c: &'alloc mut FxHashMap<Local, Vec<Local>>,
+ c: &'alloc mut FxIndexMap<Local, Vec<Local>>,
/// A reverse index of the `c` set; if the `c` set contains `a => Place { local: b, proj }`,
/// then this contains `b => a`.
// PERF: Possibly these should be `SmallVec`s?
- reverse: &'alloc mut FxHashMap<Local, Vec<Local>>,
+ reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>,
}
//////////////////////////////////////////////////////////
@@ -287,7 +285,7 @@ struct Candidates<'alloc> {
fn apply_merges<'tcx>(
body: &mut Body<'tcx>,
tcx: TyCtxt<'tcx>,
- merges: &FxHashMap<Local, Local>,
+ merges: &FxIndexMap<Local, Local>,
merged_locals: &BitSet<Local>,
) {
let mut merger = Merger { tcx, merges, merged_locals };
@@ -296,7 +294,7 @@ fn apply_merges<'tcx>(
struct Merger<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
- merges: &'a FxHashMap<Local, Local>,
+ merges: &'a FxIndexMap<Local, Local>,
merged_locals: &'a BitSet<Local>,
}
@@ -379,7 +377,7 @@ impl<'alloc> Candidates<'alloc> {
/// `vec_filter_candidates` but for an `Entry`
fn entry_filter_candidates(
- mut entry: OccupiedEntry<'_, Local, Vec<Local>>,
+ mut entry: IndexOccupiedEntry<'_, Local, Vec<Local>>,
p: Local,
f: impl FnMut(Local) -> CandidateFilter,
at: Location,
@@ -399,7 +397,7 @@ impl<'alloc> Candidates<'alloc> {
at: Location,
) {
// Cover the cases where `p` appears as a `src`
- if let Entry::Occupied(entry) = self.c.entry(p) {
+ if let IndexEntry::Occupied(entry) = self.c.entry(p) {
Self::entry_filter_candidates(entry, p, &mut f, at);
}
// And the cases where `p` appears as a `dest`
@@ -412,7 +410,7 @@ impl<'alloc> Candidates<'alloc> {
if f(*src) == CandidateFilter::Keep {
return true;
}
- let Entry::Occupied(entry) = self.c.entry(*src) else {
+ let IndexEntry::Occupied(entry) = self.c.entry(*src) else {
return false;
};
Self::entry_filter_candidates(
@@ -721,8 +719,8 @@ fn places_to_candidate_pair<'tcx>(
fn find_candidates<'alloc, 'tcx>(
body: &Body<'tcx>,
borrowed: &BitSet<Local>,
- candidates: &'alloc mut FxHashMap<Local, Vec<Local>>,
- candidates_reverse: &'alloc mut FxHashMap<Local, Vec<Local>>,
+ candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>,
+ candidates_reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>,
) -> Candidates<'alloc> {
candidates.clear();
candidates_reverse.clear();
@@ -744,7 +742,7 @@ fn find_candidates<'alloc, 'tcx>(
struct FindAssignments<'a, 'alloc, 'tcx> {
body: &'a Body<'tcx>,
- candidates: &'alloc mut FxHashMap<Local, Vec<Local>>,
+ candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>,
borrowed: &'a BitSet<Local>,
}
diff --git a/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-abort.diff b/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-abort.diff
index 54875cadec5b6..b461869be3189 100644
--- a/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-abort.diff
+++ b/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-abort.diff
@@ -8,20 +8,20 @@
let mut _3: u8;
bb0: {
-- StorageLive(_2);
-+ nop;
- StorageLive(_3);
- _3 = _1;
+ StorageLive(_2);
+- StorageLive(_3);
+- _3 = _1;
- _2 = dummy(move _3) -> [return: bb1, unwind unreachable];
-+ _1 = dummy(move _3) -> [return: bb1, unwind unreachable];
++ nop;
++ nop;
++ _2 = dummy(move _1) -> [return: bb1, unwind unreachable];
}
bb1: {
- StorageDead(_3);
-- _1 = move _2;
-- StorageDead(_2);
-+ nop;
+- StorageDead(_3);
+ nop;
+ _1 = move _2;
+ StorageDead(_2);
_0 = const ();
return;
}
diff --git a/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-unwind.diff b/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-unwind.diff
index b4c8a89278b9b..d5c2e07c6c234 100644
--- a/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-unwind.diff
+++ b/tests/mir-opt/dest-prop/copy_propagation_arg.foo.DestinationPropagation.panic-unwind.diff
@@ -8,20 +8,20 @@
let mut _3: u8;
bb0: {
-- StorageLive(_2);
-+ nop;
- StorageLive(_3);
- _3 = _1;
+ StorageLive(_2);
+- StorageLive(_3);
+- _3 = _1;
- _2 = dummy(move _3) -> [return: bb1, unwind continue];
-+ _1 = dummy(move _3) -> [return: bb1, unwind continue];
++ nop;
++ nop;
++ _2 = dummy(move _1) -> [return: bb1, unwind continue];
}
bb1: {
- StorageDead(_3);
-- _1 = move _2;
-- StorageDead(_2);
-+ nop;
+- StorageDead(_3);
+ nop;
+ _1 = move _2;
+ StorageDead(_2);
_0 = const ();
return;
}