From 6cd0dcade7c873209e6c220d40f811e5e72679f2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?John=20K=C3=A5re=20Alsaker?= Date: Sat, 4 Jan 2020 21:42:28 +0100 Subject: [PATCH] Prefetch queries used by the metadata encoder --- src/librustc_metadata/rmeta/encoder.rs | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs index 6280fd62de9a..625970fbfbf4 100644 --- a/src/librustc_metadata/rmeta/encoder.rs +++ b/src/librustc_metadata/rmeta/encoder.rs @@ -18,7 +18,7 @@ use rustc_ast::attr; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::stable_hasher::StableHasher; -use rustc_data_structures::sync::Lrc; +use rustc_data_structures::sync::{join, par_for_each_in, Lrc}; use rustc_hir as hir; use rustc_hir::def::CtorKind; use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE}; @@ -1721,6 +1721,22 @@ impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> { // generated regardless of trailing bytes that end up in it. pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata { + join( + || encode_metadata_impl(tcx), + || { + // Prefetch some queries used by metadata encoding + tcx.dep_graph.with_ignore(|| { + par_for_each_in(tcx.mir_keys(LOCAL_CRATE), |&def_id| { + tcx.optimized_mir(def_id); + tcx.promoted_mir(def_id); + }); + }) + }, + ) + .0 +} + +fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata { let mut encoder = opaque::Encoder::new(vec![]); encoder.emit_raw_bytes(METADATA_HEADER);