Avoid query cache sharding code in single-threaded mode

compiler/rustc_data_structures/src/sharded.rs

@@ -129,7 +129,7 @@ impl<K: Eq + Hash + Copy + IntoPointer> ShardedHashMap<K, ()> {
 }
 
 #[inline]
-fn make_hash<K: Hash + ?Sized>(val: &K) -> u64 {
+pub fn make_hash<K: Hash + ?Sized>(val: &K) -> u64 {
     let mut state = FxHasher::default();
     val.hash(&mut state);
     state.finish()

compiler/rustc_middle/src/ty/query.rs

@@ -210,7 +210,7 @@ macro_rules! define_callbacks {
 
         #[derive(Default)]
         pub struct QueryCaches<$tcx> {
-            $($(#[$attr])* pub $name: QueryCacheStore<query_storage::$name<$tcx>>,)*
+            $($(#[$attr])* pub $name: query_storage::$name<$tcx>,)*
         }
 
         impl<$tcx> TyCtxtEnsure<$tcx> {
@@ -222,12 +222,12 @@ macro_rules! define_callbacks {
 
                 let cached = try_get_cached(self.tcx, &self.tcx.query_caches.$name, &key, noop);
 
-                let lookup = match cached {
+                match cached {
                     Ok(()) => return,
-                    Err(lookup) => lookup,
-                };
+                    Err(()) => (),
+                }
 
-                self.tcx.queries.$name(self.tcx, DUMMY_SP, key, lookup, QueryMode::Ensure);
+                self.tcx.queries.$name(self.tcx, DUMMY_SP, key, QueryMode::Ensure);
             })*
         }
 
@@ -251,12 +251,12 @@ macro_rules! define_callbacks {
 
                 let cached = try_get_cached(self.tcx, &self.tcx.query_caches.$name, &key, copy);
 
-                let lookup = match cached {
+                match cached {
                     Ok(value) => return value,
-                    Err(lookup) => lookup,
-                };
+                    Err(()) => (),
+                }
 
-                self.tcx.queries.$name(self.tcx, self.span, key, lookup, QueryMode::Get).unwrap()
+                self.tcx.queries.$name(self.tcx, self.span, key, QueryMode::Get).unwrap()
             })*
         }
 
@@ -314,7 +314,6 @@ macro_rules! define_callbacks {
                 tcx: TyCtxt<$tcx>,
                 span: Span,
                 key: query_keys::$name<$tcx>,
-                lookup: QueryLookup,
                 mode: QueryMode,
             ) -> Option<query_stored::$name<$tcx>>;)*
         }

compiler/rustc_query_impl/src/on_disk_cache.rs

@@ -13,7 +13,7 @@ use rustc_middle::thir;
 use rustc_middle::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_query_system::dep_graph::DepContext;
-use rustc_query_system::query::{QueryContext, QuerySideEffects};
+use rustc_query_system::query::{QueryCache, QueryContext, QuerySideEffects};
 use rustc_serialize::{
     opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize},
     Decodable, Decoder, Encodable, Encoder,
@@ -1034,7 +1034,7 @@ where
     assert!(Q::query_state(tcx).all_inactive());
     let cache = Q::query_cache(tcx);
     let mut res = Ok(());
-    cache.iter_results(&mut |key, value, dep_node| {
+    cache.iter(&mut |key, value, dep_node| {
         if res.is_err() {
             return;
         }

compiler/rustc_query_impl/src/plumbing.rs

@@ -337,7 +337,7 @@ macro_rules! define_queries {
             }
 
             #[inline(always)]
-            fn query_cache<'a>(tcx: QueryCtxt<$tcx>) -> &'a QueryCacheStore<Self::Cache>
+            fn query_cache<'a>(tcx: QueryCtxt<$tcx>) -> &'a Self::Cache
                 where 'tcx:'a
             {
                 &tcx.query_caches.$name
@@ -538,12 +538,11 @@ macro_rules! define_queries_struct {
                 tcx: TyCtxt<$tcx>,
                 span: Span,
                 key: query_keys::$name<$tcx>,
-                lookup: QueryLookup,
                 mode: QueryMode,
             ) -> Option<query_stored::$name<$tcx>> {
                 opt_remap_env_constness!([$($modifiers)*][key]);
                 let qcx = QueryCtxt { tcx, queries: self };
-                get_query::<queries::$name<$tcx>, _>(qcx, span, key, lookup, mode)
+                get_query::<queries::$name<$tcx>, _>(qcx, span, key, mode)
             })*
         }
     };

compiler/rustc_query_impl/src/profiling_support.rs

@@ -4,7 +4,7 @@ use rustc_data_structures::profiling::SelfProfiler;
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::definitions::DefPathData;
 use rustc_middle::ty::{TyCtxt, WithOptConstParam};
-use rustc_query_system::query::{QueryCache, QueryCacheStore};
+use rustc_query_system::query::QueryCache;
 use std::fmt::Debug;
 use std::io::Write;
 
@@ -229,7 +229,7 @@ where
 fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
     tcx: TyCtxt<'tcx>,
     query_name: &'static str,
-    query_cache: &QueryCacheStore<C>,
+    query_cache: &C,
     string_cache: &mut QueryKeyStringCache,
 ) where
     C: QueryCache,
@@ -251,7 +251,7 @@ fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
             // locked while doing so. Instead we copy out the
             // `(query_key, dep_node_index)` pairs and release the lock again.
             let mut query_keys_and_indices = Vec::new();
-            query_cache.iter_results(&mut |k, _, i| query_keys_and_indices.push((k.clone(), i)));
+            query_cache.iter(&mut |k, _, i| query_keys_and_indices.push((k.clone(), i)));
 
             // Now actually allocate the strings. If allocating the strings
             // generates new entries in the query cache, we'll miss them but
@@ -276,7 +276,7 @@ fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
             let event_id = event_id_builder.from_label(query_name).to_string_id();
 
             let mut query_invocation_ids = Vec::new();
-            query_cache.iter_results(&mut |_, _, i| {
+            query_cache.iter(&mut |_, _, i| {
                 query_invocation_ids.push(i.into());
             });
 

compiler/rustc_query_system/src/query/caches.rs

@@ -1,9 +1,12 @@
 use crate::dep_graph::DepNodeIndex;
-use crate::query::plumbing::{QueryCacheStore, QueryLookup};
 
 use rustc_arena::TypedArena;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sharded;
+#[cfg(parallel_compiler)]
 use rustc_data_structures::sharded::Sharded;
+#[cfg(not(parallel_compiler))]
+use rustc_data_structures::sync::Lock;
 use rustc_data_structures::sync::WorkerLocal;
 use std::default::Default;
 use std::fmt::Debug;
@@ -25,35 +28,23 @@ pub trait QueryStorage {
 
 pub trait QueryCache: QueryStorage + Sized {
     type Key: Hash + Eq + Clone + Debug;
-    type Sharded: Default;
 
     /// Checks if the query is already computed and in the cache.
     /// It returns the shard index and a lock guard to the shard,
     /// which will be used if the query is not in the cache and we need
     /// to compute it.
-    fn lookup<'s, R, OnHit>(
+    fn lookup<R, OnHit>(
         &self,
-        state: &'s QueryCacheStore<Self>,
         key: &Self::Key,
         // `on_hit` can be called while holding a lock to the query state shard.
         on_hit: OnHit,
-    ) -> Result<R, QueryLookup>
+    ) -> Result<R, ()>
     where
         OnHit: FnOnce(&Self::Stored, DepNodeIndex) -> R;
 
-    fn complete(
-        &self,
-        lock_sharded_storage: &mut Self::Sharded,
-        key: Self::Key,
-        value: Self::Value,
-        index: DepNodeIndex,
-    ) -> Self::Stored;
+    fn complete(&self, key: Self::Key, value: Self::Value, index: DepNodeIndex) -> Self::Stored;
 
-    fn iter(
-        &self,
-        shards: &Sharded<Self::Sharded>,
-        f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex),
-    );
+    fn iter(&self, f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex));
 }
 
 pub struct DefaultCacheSelector;
@@ -62,11 +53,16 @@ impl<K: Eq + Hash, V: Clone> CacheSelector<K, V> for DefaultCacheSelector {
     type Cache = DefaultCache<K, V>;
 }
 
-pub struct DefaultCache<K, V>(PhantomData<(K, V)>);
+pub struct DefaultCache<K, V> {
+    #[cfg(parallel_compiler)]
+    cache: Sharded<FxHashMap<K, (V, DepNodeIndex)>>,
+    #[cfg(not(parallel_compiler))]
+    cache: Lock<FxHashMap<K, (V, DepNodeIndex)>>,
+}
 
 impl<K, V> Default for DefaultCache<K, V> {
     fn default() -> Self {
-        DefaultCache(PhantomData)
+        DefaultCache { cache: Default::default() }
     }
 }
 
@@ -87,49 +83,51 @@ where
     V: Clone + Debug,
 {
     type Key = K;
-    type Sharded = FxHashMap<K, (V, DepNodeIndex)>;
 
     #[inline(always)]
-    fn lookup<'s, R, OnHit>(
-        &self,
-        state: &'s QueryCacheStore<Self>,
-        key: &K,
-        on_hit: OnHit,
-    ) -> Result<R, QueryLookup>
+    fn lookup<R, OnHit>(&self, key: &K, on_hit: OnHit) -> Result<R, ()>
     where
         OnHit: FnOnce(&V, DepNodeIndex) -> R,
     {
-        let (lookup, lock) = state.get_lookup(key);
-        let result = lock.raw_entry().from_key_hashed_nocheck(lookup.key_hash, key);
+        let key_hash = sharded::make_hash(key);
+        #[cfg(parallel_compiler)]
+        let lock = self.cache.get_shard_by_hash(key_hash).lock();
+        #[cfg(not(parallel_compiler))]
+        let lock = self.cache.lock();
+        let result = lock.raw_entry().from_key_hashed_nocheck(key_hash, key);
 
         if let Some((_, value)) = result {
             let hit_result = on_hit(&value.0, value.1);
             Ok(hit_result)
         } else {
-            Err(lookup)
+            Err(())
         }
     }
 
     #[inline]
-    fn complete(
-        &self,
-        lock_sharded_storage: &mut Self::Sharded,
-        key: K,
-        value: V,
-        index: DepNodeIndex,
-    ) -> Self::Stored {
-        lock_sharded_storage.insert(key, (value.clone(), index));
+    fn complete(&self, key: K, value: V, index: DepNodeIndex) -> Self::Stored {
+        #[cfg(parallel_compiler)]
+        let mut lock = self.cache.get_shard_by_value(&key).lock();
+        #[cfg(not(parallel_compiler))]
+        let mut lock = self.cache.lock();
+        lock.insert(key, (value.clone(), index));
         value
     }
 
-    fn iter(
-        &self,
-        shards: &Sharded<Self::Sharded>,
-        f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex),
-    ) {
-        let shards = shards.lock_shards();
-        for shard in shards.iter() {
-            for (k, v) in shard.iter() {
+    fn iter(&self, f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex)) {
+        #[cfg(parallel_compiler)]
+        {
+            let shards = self.cache.lock_shards();
+            for shard in shards.iter() {
+                for (k, v) in shard.iter() {
+                    f(k, &v.0, v.1);
+                }
+            }
+        }
+        #[cfg(not(parallel_compiler))]
+        {
+            let map = self.cache.lock();
+            for (k, v) in map.iter() {
                 f(k, &v.0, v.1);
             }
         }
@@ -144,12 +142,15 @@ impl<'tcx, K: Eq + Hash, V: 'tcx> CacheSelector<K, V> for ArenaCacheSelector<'tc
 
 pub struct ArenaCache<'tcx, K, V> {
     arena: WorkerLocal<TypedArena<(V, DepNodeIndex)>>,
-    phantom: PhantomData<(K, &'tcx V)>,
+    #[cfg(parallel_compiler)]
+    cache: Sharded<FxHashMap<K, &'tcx (V, DepNodeIndex)>>,
+    #[cfg(not(parallel_compiler))]
+    cache: Lock<FxHashMap<K, &'tcx (V, DepNodeIndex)>>,
 }
 
 impl<'tcx, K, V> Default for ArenaCache<'tcx, K, V> {
     fn default() -> Self {
-        ArenaCache { arena: WorkerLocal::new(|_| TypedArena::default()), phantom: PhantomData }
+        ArenaCache { arena: WorkerLocal::new(|_| TypedArena::default()), cache: Default::default() }
     }
 }
 
@@ -171,51 +172,53 @@ where
     V: Debug,
 {
     type Key = K;
-    type Sharded = FxHashMap<K, &'tcx (V, DepNodeIndex)>;
 
     #[inline(always)]
-    fn lookup<'s, R, OnHit>(
-        &self,
-        state: &'s QueryCacheStore<Self>,
-        key: &K,
-        on_hit: OnHit,
-    ) -> Result<R, QueryLookup>
+    fn lookup<R, OnHit>(&self, key: &K, on_hit: OnHit) -> Result<R, ()>
     where
         OnHit: FnOnce(&&'tcx V, DepNodeIndex) -> R,
     {
-        let (lookup, lock) = state.get_lookup(key);
-        let result = lock.raw_entry().from_key_hashed_nocheck(lookup.key_hash, key);
+        let key_hash = sharded::make_hash(key);
+        #[cfg(parallel_compiler)]
+        let lock = self.cache.get_shard_by_hash(key_hash).lock();
+        #[cfg(not(parallel_compiler))]
+        let lock = self.cache.lock();
+        let result = lock.raw_entry().from_key_hashed_nocheck(key_hash, key);
 
         if let Some((_, value)) = result {
             let hit_result = on_hit(&&value.0, value.1);
             Ok(hit_result)
         } else {
-            Err(lookup)
+            Err(())
         }
     }
 
     #[inline]
-    fn complete(
-        &self,
-        lock_sharded_storage: &mut Self::Sharded,
-        key: K,
-        value: V,
-        index: DepNodeIndex,
-    ) -> Self::Stored {
+    fn complete(&self, key: K, value: V, index: DepNodeIndex) -> Self::Stored {
         let value = self.arena.alloc((value, index));
         let value = unsafe { &*(value as *const _) };
-        lock_sharded_storage.insert(key, value);
+        #[cfg(parallel_compiler)]
+        let mut lock = self.cache.get_shard_by_value(&key).lock();
+        #[cfg(not(parallel_compiler))]
+        let mut lock = self.cache.lock();
+        lock.insert(key, value);
         &value.0
     }
 
-    fn iter(
-        &self,
-        shards: &Sharded<Self::Sharded>,
-        f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex),
-    ) {
-        let shards = shards.lock_shards();
-        for shard in shards.iter() {
-            for (k, v) in shard.iter() {
+    fn iter(&self, f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex)) {
+        #[cfg(parallel_compiler)]
+        {
+            let shards = self.cache.lock_shards();
+            for shard in shards.iter() {
+                for (k, v) in shard.iter() {
+                    f(k, &v.0, v.1);
+                }
+            }
+        }
+        #[cfg(not(parallel_compiler))]
+        {
+            let map = self.cache.lock();
+            for (k, v) in map.iter() {
                 f(k, &v.0, v.1);
             }
         }

compiler/rustc_query_system/src/query/config.rs

@@ -4,7 +4,7 @@ use crate::dep_graph::DepNode;
 use crate::dep_graph::SerializedDepNodeIndex;
 use crate::ich::StableHashingContext;
 use crate::query::caches::QueryCache;
-use crate::query::{QueryCacheStore, QueryContext, QueryState};
+use crate::query::{QueryContext, QueryState};
 
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_errors::DiagnosticBuilder;
@@ -64,7 +64,7 @@ pub trait QueryDescription<CTX: QueryContext>: QueryConfig {
         CTX: 'a;
 
     // Don't use this method to access query results, instead use the methods on TyCtxt
-    fn query_cache<'a>(tcx: CTX) -> &'a QueryCacheStore<Self::Cache>
+    fn query_cache<'a>(tcx: CTX) -> &'a Self::Cache
     where
         CTX: 'a;
 

compiler/rustc_query_system/src/query/plumbing.rs

@@ -8,76 +8,28 @@ use crate::query::config::{QueryDescription, QueryVtable};
 use crate::query::job::{report_cycle, QueryInfo, QueryJob, QueryJobId, QueryJobInfo};
 use crate::query::{QueryContext, QueryMap, QuerySideEffects, QueryStackFrame};
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_data_structures::fx::{FxHashMap, FxHasher};
+use rustc_data_structures::fx::FxHashMap;
 #[cfg(parallel_compiler)]
 use rustc_data_structures::profiling::TimingGuard;
-use rustc_data_structures::sharded::{get_shard_index_by_hash, Sharded};
-use rustc_data_structures::sync::{Lock, LockGuard};
+#[cfg(parallel_compiler)]
+use rustc_data_structures::sharded::Sharded;
+use rustc_data_structures::sync::Lock;
 use rustc_data_structures::thin_vec::ThinVec;
 use rustc_errors::{DiagnosticBuilder, FatalError};
 use rustc_session::Session;
 use rustc_span::{Span, DUMMY_SP};
 use std::cell::Cell;
 use std::collections::hash_map::Entry;
 use std::fmt::Debug;
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
 use std::mem;
 use std::ptr;
 
-pub struct QueryCacheStore<C: QueryCache> {
-    cache: C,
-    shards: Sharded<C::Sharded>,
-}
-
-impl<C: QueryCache + Default> Default for QueryCacheStore<C> {
-    fn default() -> Self {
-        Self { cache: C::default(), shards: Default::default() }
-    }
-}
-
-/// Values used when checking a query cache which can be reused on a cache-miss to execute the query.
-pub struct QueryLookup {
-    pub(super) key_hash: u64,
-    shard: usize,
-}
-
-// We compute the key's hash once and then use it for both the
-// shard lookup and the hashmap lookup. This relies on the fact
-// that both of them use `FxHasher`.
-fn hash_for_shard<K: Hash>(key: &K) -> u64 {
-    let mut hasher = FxHasher::default();
-    key.hash(&mut hasher);
-    hasher.finish()
-}
-
-impl<C: QueryCache> QueryCacheStore<C> {
-    pub(super) fn get_lookup<'tcx>(
-        &'tcx self,
-        key: &C::Key,
-    ) -> (QueryLookup, LockGuard<'tcx, C::Sharded>) {
-        let key_hash = hash_for_shard(key);
-        let shard = get_shard_index_by_hash(key_hash);
-        let lock = self.shards.get_shard_by_index(shard).lock();
-        (QueryLookup { key_hash, shard }, lock)
-    }
-
-    pub fn iter_results(&self, f: &mut dyn FnMut(&C::Key, &C::Value, DepNodeIndex)) {
-        self.cache.iter(&self.shards, f)
-    }
-}
-
-struct QueryStateShard<K> {
-    active: FxHashMap<K, QueryResult>,
-}
-
-impl<K> Default for QueryStateShard<K> {
-    fn default() -> QueryStateShard<K> {
-        QueryStateShard { active: Default::default() }
-    }
-}
-
 pub struct QueryState<K> {
-    shards: Sharded<QueryStateShard<K>>,
+    #[cfg(parallel_compiler)]
+    active: Sharded<FxHashMap<K, QueryResult>>,
+    #[cfg(not(parallel_compiler))]
+    active: Lock<FxHashMap<K, QueryResult>>,
 }
 
 /// Indicates the state of a query for a given key in a query map.
@@ -95,8 +47,15 @@ where
     K: Eq + Hash + Clone + Debug,
 {
     pub fn all_inactive(&self) -> bool {
-        let shards = self.shards.lock_shards();
-        shards.iter().all(|shard| shard.active.is_empty())
+        #[cfg(parallel_compiler)]
+        {
+            let shards = self.active.lock_shards();
+            shards.iter().all(|shard| shard.is_empty())
+        }
+        #[cfg(not(parallel_compiler))]
+        {
+            self.active.lock().is_empty()
+        }
     }
 
     pub fn try_collect_active_jobs<CTX: Copy>(
@@ -105,11 +64,27 @@ where
         make_query: fn(CTX, K) -> QueryStackFrame,
         jobs: &mut QueryMap,
     ) -> Option<()> {
-        // We use try_lock_shards here since we are called from the
-        // deadlock handler, and this shouldn't be locked.
-        let shards = self.shards.try_lock_shards()?;
-        for shard in shards.iter() {
-            for (k, v) in shard.active.iter() {
+        #[cfg(parallel_compiler)]
+        {
+            // We use try_lock_shards here since we are called from the
+            // deadlock handler, and this shouldn't be locked.
+            let shards = self.active.try_lock_shards()?;
+            for shard in shards.iter() {
+                for (k, v) in shard.iter() {
+                    if let QueryResult::Started(ref job) = *v {
+                        let query = make_query(tcx, k.clone());
+                        jobs.insert(job.id, QueryJobInfo { query, job: job.clone() });
+                    }
+                }
+            }
+        }
+        #[cfg(not(parallel_compiler))]
+        {
+            // We use try_lock here since we are called from the
+            // deadlock handler, and this shouldn't be locked.
+            // (FIXME: Is this relevant for non-parallel compilers? It doesn't
+            // really hurt much.)
+            for (k, v) in self.active.try_lock()?.iter() {
                 if let QueryResult::Started(ref job) = *v {
                     let query = make_query(tcx, k.clone());
                     jobs.insert(job.id, QueryJobInfo { query, job: job.clone() });
@@ -123,7 +98,7 @@ where
 
 impl<K> Default for QueryState<K> {
     fn default() -> QueryState<K> {
-        QueryState { shards: Default::default() }
+        QueryState { active: Default::default() }
     }
 }
 
@@ -174,16 +149,17 @@ where
         state: &'b QueryState<K>,
         span: Span,
         key: K,
-        lookup: QueryLookup,
     ) -> TryGetJob<'b, K>
     where
         CTX: QueryContext,
     {
-        let shard = lookup.shard;
-        let mut state_lock = state.shards.get_shard_by_index(shard).lock();
+        #[cfg(parallel_compiler)]
+        let mut state_lock = state.active.get_shard_by_value(&key).lock();
+        #[cfg(not(parallel_compiler))]
+        let mut state_lock = state.active.lock();
         let lock = &mut *state_lock;
 
-        match lock.active.entry(key) {
+        match lock.entry(key) {
             Entry::Vacant(entry) => {
                 let id = tcx.next_job_id();
                 let job = tcx.current_query_job();
@@ -239,12 +215,7 @@ where
 
     /// Completes the query by updating the query cache with the `result`,
     /// signals the waiter and forgets the JobOwner, so it won't poison the query
-    fn complete<C>(
-        self,
-        cache: &QueryCacheStore<C>,
-        result: C::Value,
-        dep_node_index: DepNodeIndex,
-    ) -> C::Stored
+    fn complete<C>(self, cache: &C, result: C::Value, dep_node_index: DepNodeIndex) -> C::Stored
     where
         C: QueryCache<Key = K>,
     {
@@ -256,19 +227,17 @@ where
         mem::forget(self);
 
         let (job, result) = {
-            let key_hash = hash_for_shard(&key);
-            let shard = get_shard_index_by_hash(key_hash);
             let job = {
-                let mut lock = state.shards.get_shard_by_index(shard).lock();
-                match lock.active.remove(&key).unwrap() {
+                #[cfg(parallel_compiler)]
+                let mut lock = state.active.get_shard_by_value(&key).lock();
+                #[cfg(not(parallel_compiler))]
+                let mut lock = state.active.lock();
+                match lock.remove(&key).unwrap() {
                     QueryResult::Started(job) => job,
                     QueryResult::Poisoned => panic!(),
                 }
             };
-            let result = {
-                let mut lock = cache.shards.get_shard_by_index(shard).lock();
-                cache.cache.complete(&mut lock, key, result, dep_node_index)
-            };
+            let result = cache.complete(key, result, dep_node_index);
             (job, result)
         };
 
@@ -286,14 +255,16 @@ where
     fn drop(&mut self) {
         // Poison the query so jobs waiting on it panic.
         let state = self.state;
-        let shard = state.shards.get_shard_by_value(&self.key);
         let job = {
-            let mut shard = shard.lock();
-            let job = match shard.active.remove(&self.key).unwrap() {
+            #[cfg(parallel_compiler)]
+            let mut shard = state.active.get_shard_by_value(&self.key).lock();
+            #[cfg(not(parallel_compiler))]
+            let mut shard = state.active.lock();
+            let job = match shard.remove(&self.key).unwrap() {
                 QueryResult::Started(job) => job,
                 QueryResult::Poisoned => panic!(),
             };
-            shard.active.insert(self.key.clone(), QueryResult::Poisoned);
+            shard.insert(self.key.clone(), QueryResult::Poisoned);
             job
         };
         // Also signal the completion of the job, so waiters
@@ -334,17 +305,17 @@ where
 #[inline]
 pub fn try_get_cached<'a, CTX, C, R, OnHit>(
     tcx: CTX,
-    cache: &'a QueryCacheStore<C>,
+    cache: &'a C,
     key: &C::Key,
     // `on_hit` can be called while holding a lock to the query cache
     on_hit: OnHit,
-) -> Result<R, QueryLookup>
+) -> Result<R, ()>
 where
     C: QueryCache,
     CTX: DepContext,
     OnHit: FnOnce(&C::Stored) -> R,
 {
-    cache.cache.lookup(cache, &key, |value, index| {
+    cache.lookup(&key, |value, index| {
         if unlikely!(tcx.profiler().enabled()) {
             tcx.profiler().query_cache_hit(index.into());
         }
@@ -356,10 +327,9 @@ where
 fn try_execute_query<CTX, C>(
     tcx: CTX,
     state: &QueryState<C::Key>,
-    cache: &QueryCacheStore<C>,
+    cache: &C,
     span: Span,
     key: C::Key,
-    lookup: QueryLookup,
     dep_node: Option<DepNode<CTX::DepKind>>,
     query: &QueryVtable<CTX, C::Key, C::Value>,
 ) -> (C::Stored, Option<DepNodeIndex>)
@@ -368,21 +338,20 @@ where
     C::Key: Clone + DepNodeParams<CTX::DepContext>,
     CTX: QueryContext,
 {
-    match JobOwner::<'_, C::Key>::try_start(&tcx, state, span, key.clone(), lookup) {
+    match JobOwner::<'_, C::Key>::try_start(&tcx, state, span, key.clone()) {
         TryGetJob::NotYetStarted(job) => {
             let (result, dep_node_index) = execute_job(tcx, key, dep_node, query, job.id);
             let result = job.complete(cache, result, dep_node_index);
             (result, Some(dep_node_index))
         }
         TryGetJob::Cycle(error) => {
-            let result = mk_cycle(tcx, error, query.handle_cycle_error, &cache.cache);
+            let result = mk_cycle(tcx, error, query.handle_cycle_error, cache);
             (result, None)
         }
         #[cfg(parallel_compiler)]
         TryGetJob::JobCompleted(query_blocked_prof_timer) => {
             let (v, index) = cache
-                .cache
-                .lookup(cache, &key, |value, index| (value.clone(), index))
+                .lookup(&key, |value, index| (value.clone(), index))
                 .unwrap_or_else(|_| panic!("value must be in cache after waiting"));
 
             if unlikely!(tcx.dep_context().profiler().enabled()) {
@@ -711,13 +680,7 @@ pub enum QueryMode {
     Ensure,
 }
 
-pub fn get_query<Q, CTX>(
-    tcx: CTX,
-    span: Span,
-    key: Q::Key,
-    lookup: QueryLookup,
-    mode: QueryMode,
-) -> Option<Q::Stored>
+pub fn get_query<Q, CTX>(tcx: CTX, span: Span, key: Q::Key, mode: QueryMode) -> Option<Q::Stored>
 where
     Q: QueryDescription<CTX>,
     Q::Key: DepNodeParams<CTX::DepContext>,
@@ -741,7 +704,6 @@ where
         Q::query_cache(tcx),
         span,
         key,
-        lookup,
         dep_node,
         &query,
     );
@@ -760,20 +722,20 @@ where
     // We may be concurrently trying both execute and force a query.
     // Ensure that only one of them runs the query.
     let cache = Q::query_cache(tcx);
-    let cached = cache.cache.lookup(cache, &key, |_, index| {
+    let cached = cache.lookup(&key, |_, index| {
         if unlikely!(tcx.dep_context().profiler().enabled()) {
             tcx.dep_context().profiler().query_cache_hit(index.into());
         }
     });
 
-    let lookup = match cached {
+    match cached {
         Ok(()) => return,
-        Err(lookup) => lookup,
-    };
+        Err(()) => {}
+    }
 
     let query = Q::make_vtable(tcx, &key);
     let state = Q::query_state(tcx);
     debug_assert!(!query.anon);
 
-    try_execute_query(tcx, state, cache, DUMMY_SP, key, lookup, Some(dep_node), &query);
+    try_execute_query(tcx, state, cache, DUMMY_SP, key, Some(dep_node), &query);
 }