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This commit is contained in:
John Kåre Alsaker 2020-03-14 13:39:33 +01:00
parent a2bca90077
commit 801e4420b6
1 changed files with 15 additions and 1 deletions
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16
src/librustc_metadata/rmeta/encoder.rs
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@ -508,7 +508,8 @@ impl<'tcx> EncodeContext<'tcx> {
let proc_macro_data = self.encode_proc_macros();
let proc_macro_data_bytes = self.position() - i;
// Encode exported symbols info.
// Encode exported symbols info. This is prefetched in `encode_metadata` so we encode
// this last to give the prefetching as much time as possible to complete.
i = self.position();
let exported_symbols = self.tcx.exported_symbols(LOCAL_CRATE);
let exported_symbols = self.encode_exported_symbols(&exported_symbols);
@ -889,6 +890,8 @@ impl EncodeContext<'tcx> {
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
// This should be kept in sync with `PrefetchVisitor.visit_trait_item`.
self.encode_optimized_mir(def_id);
self.encode_promoted_mir(def_id);
}
@ -960,6 +963,9 @@ impl EncodeContext<'tcx> {
self.encode_generics(def_id);
self.encode_explicit_predicates(def_id);
self.encode_inferred_outlives(def_id);
// The following part should be kept in sync with `PrefetchVisitor.visit_impl_item`.
let mir = match ast_item.kind {
hir::ImplItemKind::Const(..) => true,
hir::ImplItemKind::Fn(ref sig, _) => {
@ -1251,6 +1257,8 @@ impl EncodeContext<'tcx> {
_ => {}
}
// The following part should be kept in sync with `PrefetchVisitor.visit_item`.
let mir = match item.kind {
hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => true,
hir::ItemKind::Fn(ref sig, ..) => {
@ -1699,6 +1707,7 @@ impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> {
}
/// Used to prefetch queries which will be needed later by metadata encoding.
/// Only a subset of the queries are actually prefetched to keep this code smaller.
struct PrefetchVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
mir_keys: &'tcx DefIdSet,
@ -1715,6 +1724,7 @@ impl<'tcx> PrefetchVisitor<'tcx> {
impl<'tcx, 'v> ParItemLikeVisitor<'v> for PrefetchVisitor<'tcx> {
fn visit_item(&self, item: &hir::Item<'_>) {
// This should be kept in sync with `encode_info_for_item`.
let tcx = self.tcx;
match item.kind {
hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => {
@ -1734,10 +1744,12 @@ impl<'tcx, 'v> ParItemLikeVisitor<'v> for PrefetchVisitor<'tcx> {
}
fn visit_trait_item(&self, trait_item: &'v hir::TraitItem<'v>) {
// This should be kept in sync with `encode_info_for_trait_item`.
self.prefetch_mir(self.tcx.hir().local_def_id(trait_item.hir_id));
}
fn visit_impl_item(&self, impl_item: &'v hir::ImplItem<'v>) {
// This should be kept in sync with `encode_info_for_impl_item`.
let tcx = self.tcx;
match impl_item.kind {
hir::ImplItemKind::Const(..) => {
@ -1789,6 +1801,8 @@ pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
return;
}
// Prefetch some queries used by metadata encoding.
// This is not necessary for correctness, but is only done for performance reasons.
// It can be removed if it turns out to cause trouble or be detrimental to performance.
tcx.dep_graph.with_ignore(|| {
join(
|| {