diff --git a/compiler/rustc_middle/src/ty/fast_reject.rs b/compiler/rustc_middle/src/ty/fast_reject.rs
index ee505742be9a0..40de2901a5645 100644
--- a/compiler/rustc_middle/src/ty/fast_reject.rs
+++ b/compiler/rustc_middle/src/ty/fast_reject.rs
@@ -103,6 +103,7 @@ pub enum TreatProjections {
 /// is only correct if they are fully normalized.
 ///
 /// ¹ meaning that if the outermost layers are different, then the whole types are also different.
+#[inline(always)]
 pub fn simplify_type<'tcx>(
     tcx: TyCtxt<'tcx>,
     ty: Ty<'tcx>,
diff --git a/compiler/rustc_middle/src/ty/trait_def.rs b/compiler/rustc_middle/src/ty/trait_def.rs
index bf2b121f704af..e62b08f4b1080 100644
--- a/compiler/rustc_middle/src/ty/trait_def.rs
+++ b/compiler/rustc_middle/src/ty/trait_def.rs
@@ -118,6 +118,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Iterate over every impl that could possibly match the self type `self_ty`.
     ///
     /// `trait_def_id` MUST BE the `DefId` of a trait.
+    #[inline(always)]
     pub fn for_each_relevant_impl(
         self,
         trait_def_id: DefId,
@@ -132,6 +133,7 @@ impl<'tcx> TyCtxt<'tcx> {
         )
     }
 
+    #[inline(always)]
     pub fn for_each_relevant_impl_treating_projections(
         self,
         trait_def_id: DefId,