diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 46c098c8236a0..805be431328e2 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -3653,6 +3653,7 @@ assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));
 assert_eq!(", stringify!($SelfT), "::max_value().checked_next_power_of_two(), None);",
 $EndFeature, "
 ```"),
+            #[inline]
             #[stable(feature = "rust1", since = "1.0.0")]
             pub fn checked_next_power_of_two(self) -> Option<Self> {
                 self.one_less_than_next_power_of_two().checked_add(1)
diff --git a/src/librustc/infer/at.rs b/src/librustc/infer/at.rs
index 0e4c94aaaf394..70e922c6676e1 100644
--- a/src/librustc/infer/at.rs
+++ b/src/librustc/infer/at.rs
@@ -52,6 +52,7 @@ pub struct Trace<'a, 'gcx: 'tcx, 'tcx: 'a> {
 }
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
+    #[inline]
     pub fn at(&'a self,
               cause: &'a ObligationCause<'tcx>,
               param_env: ty::ParamEnv<'tcx>)
diff --git a/src/librustc/infer/resolve.rs b/src/librustc/infer/resolve.rs
index a0c310ac2761e..7a1ee85acd42c 100644
--- a/src/librustc/infer/resolve.rs
+++ b/src/librustc/infer/resolve.rs
@@ -25,6 +25,7 @@ pub struct OpportunisticTypeResolver<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
 }
 
 impl<'a, 'gcx, 'tcx> OpportunisticTypeResolver<'a, 'gcx, 'tcx> {
+    #[inline]
     pub fn new(infcx: &'a InferCtxt<'a, 'gcx, 'tcx>) -> Self {
         OpportunisticTypeResolver { infcx }
     }
diff --git a/src/librustc/traits/mod.rs b/src/librustc/traits/mod.rs
index e582a9020464d..ab2fa68ab5f89 100644
--- a/src/librustc/traits/mod.rs
+++ b/src/librustc/traits/mod.rs
@@ -1052,6 +1052,7 @@ impl<'tcx,O> Obligation<'tcx,O> {
 }
 
 impl<'tcx> ObligationCause<'tcx> {
+    #[inline]
     pub fn new(span: Span,
                body_id: ast::NodeId,
                code: ObligationCauseCode<'tcx>)
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 79a4638d6f7d9..ebcf83cb8ecad 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -155,6 +155,7 @@ impl<'gcx: 'tcx, 'tcx> CtxtInterners<'tcx> {
     }
 
     /// Intern a type
+    #[inline(never)]
     fn intern_ty(
         local: &CtxtInterners<'tcx>,
         global: &CtxtInterners<'gcx>,
@@ -216,6 +217,7 @@ impl<'gcx: 'tcx, 'tcx> CtxtInterners<'tcx> {
 }
 
 pub struct CommonTypes<'tcx> {
+    pub unit: Ty<'tcx>,
     pub bool: Ty<'tcx>,
     pub char: Ty<'tcx>,
     pub isize: Ty<'tcx>,
@@ -832,7 +834,9 @@ impl<'tcx> CommonTypes<'tcx> {
             interners.region.borrow_mut().insert(Interned(r));
             &*r
         };
+
         CommonTypes {
+            unit: mk(Tuple(List::empty())),
             bool: mk(Bool),
             char: mk(Char),
             never: mk(Never),
@@ -885,6 +889,7 @@ pub struct TyCtxt<'a, 'gcx: 'tcx, 'tcx: 'a> {
 
 impl<'a, 'gcx, 'tcx> Deref for TyCtxt<'a, 'gcx, 'tcx> {
     type Target = &'a GlobalCtxt<'gcx>;
+    #[inline(always)]
     fn deref(&self) -> &Self::Target {
         &self.gcx
     }
@@ -2515,6 +2520,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.mk_fn_ptr(converted_sig)
     }
 
+    #[inline]
     pub fn mk_ty(&self, st: TyKind<'tcx>) -> Ty<'tcx> {
         CtxtInterners::intern_ty(&self.interners, &self.global_interners, st)
     }
@@ -2548,19 +2554,23 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
+    #[inline]
     pub fn mk_str(self) -> Ty<'tcx> {
         self.mk_ty(Str)
     }
 
+    #[inline]
     pub fn mk_static_str(self) -> Ty<'tcx> {
         self.mk_imm_ref(self.types.re_static, self.mk_str())
     }
 
+    #[inline]
     pub fn mk_adt(self, def: &'tcx AdtDef, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
         // take a copy of substs so that we own the vectors inside
         self.mk_ty(Adt(def, substs))
     }
 
+    #[inline]
     pub fn mk_foreign(self, def_id: DefId) -> Ty<'tcx> {
         self.mk_ty(Foreign(def_id))
     }
@@ -2584,42 +2594,52 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.mk_ty(Adt(adt_def, substs))
     }
 
+    #[inline]
     pub fn mk_ptr(self, tm: TypeAndMut<'tcx>) -> Ty<'tcx> {
         self.mk_ty(RawPtr(tm))
     }
 
+    #[inline]
     pub fn mk_ref(self, r: Region<'tcx>, tm: TypeAndMut<'tcx>) -> Ty<'tcx> {
         self.mk_ty(Ref(r, tm.ty, tm.mutbl))
     }
 
+    #[inline]
     pub fn mk_mut_ref(self, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutMutable})
     }
 
+    #[inline]
     pub fn mk_imm_ref(self, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutImmutable})
     }
 
+    #[inline]
     pub fn mk_mut_ptr(self, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ptr(TypeAndMut {ty: ty, mutbl: hir::MutMutable})
     }
 
+    #[inline]
     pub fn mk_imm_ptr(self, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ptr(TypeAndMut {ty: ty, mutbl: hir::MutImmutable})
     }
 
+    #[inline]
     pub fn mk_nil_ptr(self) -> Ty<'tcx> {
         self.mk_imm_ptr(self.mk_unit())
     }
 
+    #[inline]
     pub fn mk_array(self, ty: Ty<'tcx>, n: u64) -> Ty<'tcx> {
         self.mk_ty(Array(ty, ty::Const::from_usize(self, n)))
     }
 
+    #[inline]
     pub fn mk_slice(self, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ty(Slice(ty))
     }
 
+    #[inline]
     pub fn intern_tup(self, ts: &[Ty<'tcx>]) -> Ty<'tcx> {
         self.mk_ty(Tuple(self.intern_type_list(ts)))
     }
@@ -2628,10 +2648,12 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         iter.intern_with(|ts| self.mk_ty(Tuple(self.intern_type_list(ts))))
     }
 
+    #[inline]
     pub fn mk_unit(self) -> Ty<'tcx> {
-        self.intern_tup(&[])
+        self.types.unit
     }
 
+    #[inline]
     pub fn mk_diverging_default(self) -> Ty<'tcx> {
         if self.features().never_type {
             self.types.never
@@ -2640,19 +2662,23 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
+    #[inline]
     pub fn mk_bool(self) -> Ty<'tcx> {
         self.mk_ty(Bool)
     }
 
+    #[inline]
     pub fn mk_fn_def(self, def_id: DefId,
                      substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
         self.mk_ty(FnDef(def_id, substs))
     }
 
+    #[inline]
     pub fn mk_fn_ptr(self, fty: PolyFnSig<'tcx>) -> Ty<'tcx> {
         self.mk_ty(FnPtr(fty))
     }
 
+    #[inline]
     pub fn mk_dynamic(
         self,
         obj: ty::Binder<&'tcx List<ExistentialPredicate<'tcx>>>,
@@ -2661,6 +2687,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.mk_ty(Dynamic(obj, reg))
     }
 
+    #[inline]
     pub fn mk_projection(self,
                          item_def_id: DefId,
                          substs: &'tcx Substs<'tcx>)
@@ -2671,11 +2698,13 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             }))
         }
 
+    #[inline]
     pub fn mk_closure(self, closure_id: DefId, closure_substs: ClosureSubsts<'tcx>)
                       -> Ty<'tcx> {
         self.mk_ty(Closure(closure_id, closure_substs))
     }
 
+    #[inline]
     pub fn mk_generator(self,
                         id: DefId,
                         generator_substs: GeneratorSubsts<'tcx>,
@@ -2684,32 +2713,39 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.mk_ty(Generator(id, generator_substs, movability))
     }
 
+    #[inline]
     pub fn mk_generator_witness(self, types: ty::Binder<&'tcx List<Ty<'tcx>>>) -> Ty<'tcx> {
         self.mk_ty(GeneratorWitness(types))
     }
 
+    #[inline]
     pub fn mk_var(self, v: TyVid) -> Ty<'tcx> {
         self.mk_infer(TyVar(v))
     }
 
+    #[inline]
     pub fn mk_int_var(self, v: IntVid) -> Ty<'tcx> {
         self.mk_infer(IntVar(v))
     }
 
+    #[inline]
     pub fn mk_float_var(self, v: FloatVid) -> Ty<'tcx> {
         self.mk_infer(FloatVar(v))
     }
 
+    #[inline]
     pub fn mk_infer(self, it: InferTy) -> Ty<'tcx> {
         self.mk_ty(Infer(it))
     }
 
+    #[inline]
     pub fn mk_ty_param(self,
                        index: u32,
                        name: InternedString) -> Ty<'tcx> {
         self.mk_ty(Param(ParamTy { idx: index, name: name }))
     }
 
+    #[inline]
     pub fn mk_self_type(self) -> Ty<'tcx> {
         self.mk_ty_param(0, keywords::SelfType.name().as_interned_str())
     }
@@ -2723,6 +2759,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
+    #[inline]
     pub fn mk_opaque(self, def_id: DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
         self.mk_ty(Opaque(def_id, substs))
     }
diff --git a/src/librustc/ty/fold.rs b/src/librustc/ty/fold.rs
index 6f0e8d4f02680..1bc7d64879267 100644
--- a/src/librustc/ty/fold.rs
+++ b/src/librustc/ty/fold.rs
@@ -374,6 +374,7 @@ pub struct RegionFolder<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
 }
 
 impl<'a, 'gcx, 'tcx> RegionFolder<'a, 'gcx, 'tcx> {
+    #[inline]
     pub fn new(
         tcx: TyCtxt<'a, 'gcx, 'tcx>,
         skipped_regions: &'a mut bool,
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index b371f4532e5fa..4633ab1166347 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -1275,6 +1275,7 @@ impl<'tcx> PolyProjectionPredicate<'tcx> {
         self.skip_binder().projection_ty.item_def_id
     }
 
+    #[inline]
     pub fn to_poly_trait_ref(&self, tcx: TyCtxt<'_, '_, '_>) -> PolyTraitRef<'tcx> {
         // Note: unlike with `TraitRef::to_poly_trait_ref()`,
         // `self.0.trait_ref` is permitted to have escaping regions.
@@ -1633,6 +1634,7 @@ impl<'tcx> ParamEnv<'tcx> {
     /// there are no where clauses in scope. Hidden types (like `impl
     /// Trait`) are left hidden, so this is suitable for ordinary
     /// type-checking.
+    #[inline]
     pub fn empty() -> Self {
         Self::new(List::empty(), Reveal::UserFacing)
     }
@@ -1644,11 +1646,13 @@ impl<'tcx> ParamEnv<'tcx> {
     ///
     /// N.B. If you want to have predicates in scope, use `ParamEnv::new`,
     /// or invoke `param_env.with_reveal_all()`.
+    #[inline]
     pub fn reveal_all() -> Self {
         Self::new(List::empty(), Reveal::All)
     }
 
     /// Construct a trait environment with the given set of predicates.
+    #[inline]
     pub fn new(caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
                reveal: Reveal)
                -> Self {
@@ -2148,6 +2152,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
         }
     }
 
+    #[inline]
     pub fn variant_descr(&self) -> &'static str {
         match self.adt_kind() {
             AdtKind::Struct => "struct",
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index a18e3a275467d..1416cb17feaed 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -667,6 +667,7 @@ impl<'tcx> TraitRef<'tcx> {
         }
     }
 
+    #[inline]
     pub fn self_ty(&self) -> Ty<'tcx> {
         self.substs.type_at(0)
     }
@@ -978,15 +979,18 @@ impl<'tcx> FnSig<'tcx> {
 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
 
 impl<'tcx> PolyFnSig<'tcx> {
+    #[inline]
     pub fn inputs(&self) -> Binder<&'tcx [Ty<'tcx>]> {
         self.map_bound_ref(|fn_sig| fn_sig.inputs())
     }
+    #[inline]
     pub fn input(&self, index: usize) -> ty::Binder<Ty<'tcx>> {
         self.map_bound_ref(|fn_sig| fn_sig.inputs()[index])
     }
     pub fn inputs_and_output(&self) -> ty::Binder<&'tcx List<Ty<'tcx>>> {
         self.map_bound_ref(|fn_sig| fn_sig.inputs_and_output)
     }
+    #[inline]
     pub fn output(&self) -> ty::Binder<Ty<'tcx>> {
         self.map_bound_ref(|fn_sig| fn_sig.output())
     }
@@ -1548,6 +1552,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    #[inline]
     pub fn is_ty_var(&self) -> bool {
         match self.sty {
             Infer(TyVar(_)) => true,
@@ -1732,6 +1737,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    #[inline]
     pub fn is_integral(&self) -> bool {
         match self.sty {
             Infer(IntVar(_)) | Int(_) | Uint(_) => true,
@@ -1762,6 +1768,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    #[inline]
     pub fn is_fp(&self) -> bool {
         match self.sty {
             Infer(FloatVar(_)) | Float(_) => true,
@@ -1845,6 +1852,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    #[inline]
     pub fn ty_adt_def(&self) -> Option<&'tcx AdtDef> {
         match self.sty {
             Adt(adt, _) => Some(adt),
diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index 65f6d27239b83..34fb71e4ddf68 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -587,6 +587,7 @@ impl fmt::Debug for SpanData {
 }
 
 impl MultiSpan {
+    #[inline]
     pub fn new() -> MultiSpan {
         MultiSpan {
             primary_spans: vec![],