From f8b019fc0a38d0b110458f3ae4807ec51a05241e Mon Sep 17 00:00:00 2001
From: Joshua Nelson <jnelson@cloudflare.com>
Date: Mon, 29 Aug 2022 20:52:12 -0500
Subject: [PATCH 1/2] Move most of `TyCtxtAt::$name` into a generic function
---
compiler/rustc_middle/src/ty/query.rs | 48 ++++++++++++++++-----------
1 file changed, 28 insertions(+), 20 deletions(-)
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index 5665bb866d46c..c0142e6f882da 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -102,16 +102,38 @@ impl<'tcx> TyCtxt<'tcx> {
}
}
-/// Helper for `TyCtxtEnsure` to avoid a closure.
-#[inline(always)]
-fn noop<T>(_: &T) {}
-
/// Helper to ensure that queries only return `Copy` types.
#[inline(always)]
fn copy<T: Copy>(x: &T) -> T {
*x
}
+fn evaluate_query<'tcx, Cache>(
+ tcx: TyCtxt<'tcx>,
+ execute_query: fn(
+ &'tcx dyn QueryEngine<'tcx>,
+ TyCtxt<'tcx>,
+ Span,
+ Cache::Key,
+ QueryMode,
+ ) -> Option<Cache::Stored>,
+ query_cache: &Cache,
+ span: Span,
+ key: Cache::Key,
+ mode: QueryMode,
+) -> Option<Cache::Stored>
+where
+ Cache::Stored: Copy,
+ Cache: QueryCache,
+{
+ let cached = try_get_cached(tcx, query_cache, &key, copy);
+
+ match cached {
+ Ok(value) => return value,
+ Err(()) => (),
+ }
+}
+
macro_rules! query_helper_param_ty {
(DefId) => { impl IntoQueryParam<DefId> };
($K:ty) => { $K };
@@ -220,14 +242,7 @@ macro_rules! define_callbacks {
let key = key.into_query_param();
opt_remap_env_constness!([$($modifiers)*][key]);
- let cached = try_get_cached(self.tcx, &self.tcx.query_caches.$name, &key, noop);
-
- match cached {
- Ok(()) => return,
- Err(()) => (),
- }
-
- self.tcx.queries.$name(self.tcx, DUMMY_SP, key, QueryMode::Ensure);
+ let _ = evaluate_query(self.tcx, QueryEngine::$name, &self.tcx.query_caches.$name, DUMMY_SP, key, QueryMode::Ensure);
})*
}
@@ -249,14 +264,7 @@ macro_rules! define_callbacks {
let key = key.into_query_param();
opt_remap_env_constness!([$($modifiers)*][key]);
- let cached = try_get_cached(self.tcx, &self.tcx.query_caches.$name, &key, copy);
-
- match cached {
- Ok(value) => return value,
- Err(()) => (),
- }
-
- self.tcx.queries.$name(self.tcx, self.span, key, QueryMode::Get).unwrap()
+ evaluate_query(self.tcx, QueryEngine::$name, &self.tcx.query_caches.$name, self.span, key, QueryMode::Get).unwrap()
})*
}
From 3675fdd28ea8676fbf579a30e4cff78e4e9ae160 Mon Sep 17 00:00:00 2001
From: Joshua Nelson <jnelson@cloudflare.com>
Date: Fri, 9 Sep 2022 20:46:36 -0500
Subject: [PATCH 2/2] Get rid of OnHit by switching on `QueryMode` instead of
unconditionally returning Option
I think `copy` may have added some overhead? unclear what's causing the perf impact.
---
compiler/rustc_middle/src/ty/query.rs | 14 +++-----------
compiler/rustc_query_system/src/query/plumbing.rs | 13 ++++++-------
2 files changed, 9 insertions(+), 18 deletions(-)
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index c0142e6f882da..eb8f6a1175a90 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -102,12 +102,6 @@ impl<'tcx> TyCtxt<'tcx> {
}
}
-/// Helper to ensure that queries only return `Copy` types.
-#[inline(always)]
-fn copy<T: Copy>(x: &T) -> T {
- *x
-}
-
fn evaluate_query<'tcx, Cache>(
tcx: TyCtxt<'tcx>,
execute_query: fn(
@@ -126,11 +120,9 @@ where
Cache::Stored: Copy,
Cache: QueryCache,
{
- let cached = try_get_cached(tcx, query_cache, &key, copy);
-
- match cached {
- Ok(value) => return value,
- Err(()) => (),
+ match try_get_cached(tcx, query_cache, &key, mode) {
+ Ok(value) => value,
+ Err(()) => execute_query(tcx.queries, tcx, span, key, mode),
}
}
diff --git a/compiler/rustc_query_system/src/query/plumbing.rs b/compiler/rustc_query_system/src/query/plumbing.rs
index 7bbc22e8293a5..891558e314b87 100644
--- a/compiler/rustc_query_system/src/query/plumbing.rs
+++ b/compiler/rustc_query_system/src/query/plumbing.rs
@@ -303,24 +303,23 @@ where
/// which will be used if the query is not in the cache and we need
/// to compute it.
#[inline]
-pub fn try_get_cached<'a, CTX, C, R, OnHit>(
+pub fn try_get_cached<'a, CTX, C>(
tcx: CTX,
cache: &'a C,
key: &C::Key,
- // `on_hit` can be called while holding a lock to the query cache
- on_hit: OnHit,
-) -> Result<R, ()>
+ mode: QueryMode,
+) -> Result<Option<C::Stored>, ()>
where
C: QueryCache,
+ C::Stored: Copy,
CTX: DepContext,
- OnHit: FnOnce(&C::Stored) -> R,
{
cache.lookup(&key, |value, index| {
if std::intrinsics::unlikely(tcx.profiler().enabled()) {
tcx.profiler().query_cache_hit(index.into());
}
tcx.dep_graph().read_index(index);
- on_hit(value)
+ if matches!(mode, QueryMode::Ensure) { None } else { Some(*value) }
})
}
@@ -676,7 +675,7 @@ where
}
}
-#[derive(Debug)]
+#[derive(Copy, Clone, Debug)]
pub enum QueryMode {
Get,
Ensure,