Update compiler/rustc_middle/src/query/mod.rs

Co-authored-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
rust-lang · May 27, 2021 · 9385be7 · 9385be7
1 parent fdc15ef
commit 9385be7
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
@@ -222,6 +222,7 @@ rustc_queries! {
 
     /// Fetch the THIR for a given body. If typeck for that body failed, returns an empty `Thir`.
     query thir_body(key: ty::WithOptConstParam<LocalDefId>) -> (&'tcx Steal<thir::Thir<'tcx>>, thir::ExprId) {
+        // Perf tests revealed that hashing THIR is inefficient (see #85729).
         no_hash
         desc { |tcx| "building THIR for `{}`", tcx.def_path_str(key.did.to_def_id()) }
     }