bjoernager/rust
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Separate the query cache from the query state.

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This commit is contained in:
Camille GILLOT 2021-02-06 13:49:08 +01:00
parent 9f46259a75
commit 15b0bc6b83
9 changed files with 174 additions and 136 deletions
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30
compiler/rustc_data_structures/src/sharded.rs
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@ -63,23 +63,9 @@ impl<T> Sharded<T> {
if SHARDS == 1 { &self.shards[0].0 } else { self.get_shard_by_hash(make_hash(val)) }
}
/// Get a shard with a pre-computed hash value. If `get_shard_by_value` is
/// ever used in combination with `get_shard_by_hash` on a single `Sharded`
/// instance, then `hash` must be computed with `FxHasher`. Otherwise,
/// `hash` can be computed with any hasher, so long as that hasher is used
/// consistently for each `Sharded` instance.
#[inline]
pub fn get_shard_index_by_hash(&self, hash: u64) -> usize {
let hash_len = mem::size_of::<usize>();
// Ignore the top 7 bits as hashbrown uses these and get the next SHARD_BITS highest bits.
// hashbrown also uses the lowest bits, so we can't use those
let bits = (hash >> (hash_len * 8 - 7 - SHARD_BITS)) as usize;
bits % SHARDS
}
#[inline]
pub fn get_shard_by_hash(&self, hash: u64) -> &Lock<T> {
&self.shards[self.get_shard_index_by_hash(hash)].0
&self.shards[get_shard_index_by_hash(hash)].0
}
#[inline]
@ -166,3 +152,17 @@ fn make_hash<K: Hash + ?Sized>(val: &K) -> u64 {
val.hash(&mut state);
state.finish()
}
/// Get a shard with a pre-computed hash value. If `get_shard_by_value` is
/// ever used in combination with `get_shard_by_hash` on a single `Sharded`
/// instance, then `hash` must be computed with `FxHasher`. Otherwise,
/// `hash` can be computed with any hasher, so long as that hasher is used
/// consistently for each `Sharded` instance.
#[inline]
pub fn get_shard_index_by_hash(hash: u64) -> usize {
let hash_len = mem::size_of::<usize>();
// Ignore the top 7 bits as hashbrown uses these and get the next SHARD_BITS highest bits.
// hashbrown also uses the lowest bits, so we can't use those
let bits = (hash >> (hash_len * 8 - 7 - SHARD_BITS)) as usize;
bits % SHARDS
}