diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index 3d6eef88696..58dc331c7a2 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -800,6 +800,7 @@ where
     }
 }
 
+#[inline(always)]
 fn select_name<'a, T>(is_html: bool, local_name: &'a T, local_name_lower: &'a T) -> &'a T {
     if is_html {
         local_name_lower
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 343d6fca05b..88ee70bde25 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -423,6 +423,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
     /// Whether this selector (pseudo-element part excluded) matches every element.
     ///
     /// Used for "pre-computed" pseudo-elements in components/style/stylist.rs
+    #[inline]
     pub fn is_universal(&self) -> bool {
         self.iter_raw_match_order().all(|c| matches!(*c,
             Component::ExplicitUniversalType |
@@ -435,6 +436,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
     /// Returns an iterator over this selector in matching order (right-to-left).
     /// When a combinator is reached, the iterator will return None, and
     /// next_sequence() may be called to continue to the next sequence.
+    #[inline]
     pub fn iter(&self) -> SelectorIter<Impl> {
         SelectorIter {
             iter: self.iter_raw_match_order(),
@@ -444,6 +446,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
 
     /// Returns an iterator over this selector in matching order (right-to-left),
     /// skipping the rightmost |offset| Components.
+    #[inline]
     pub fn iter_from(&self, offset: usize) -> SelectorIter<Impl> {
         let iter = self.0.slice[offset..].iter();
         SelectorIter {
@@ -467,6 +470,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
 
     /// Returns an iterator over the entire sequence of simple selectors and
     /// combinators, in matching order (from right to left).
+    #[inline]
     pub fn iter_raw_match_order(&self) -> slice::Iter<Component<Impl>> {
         self.0.slice.iter()
     }
@@ -487,6 +491,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
     /// Returns an iterator over the sequence of simple selectors and
     /// combinators, in parse order (from left to right), starting from
     /// `offset`.
+    #[inline]
     pub fn iter_raw_parse_order_from(&self, offset: usize) -> Rev<slice::Iter<Component<Impl>>> {
         self.0.slice[..self.len() - offset].iter().rev()
     }
@@ -506,6 +511,7 @@ impl<Impl: SelectorImpl> Selector<Impl> {
     }
 
     /// Returns count of simple selectors and combinators in the Selector.
+    #[inline]
     pub fn len(&self) -> usize {
         self.0.slice.len()
     }
@@ -525,11 +531,13 @@ pub struct SelectorIter<'a, Impl: 'a + SelectorImpl> {
 impl<'a, Impl: 'a + SelectorImpl> SelectorIter<'a, Impl> {
     /// Prepares this iterator to point to the next sequence to the left,
     /// returning the combinator if the sequence was found.
+    #[inline]
     pub fn next_sequence(&mut self) -> Option<Combinator> {
         self.next_combinator.take()
     }
 
     /// Returns remaining count of the simple selectors and combinators in the Selector.
+    #[inline]
     pub fn selector_length(&self) -> usize {
         self.iter.len()
     }
@@ -537,6 +545,8 @@ impl<'a, Impl: 'a + SelectorImpl> SelectorIter<'a, Impl> {
 
 impl<'a, Impl: SelectorImpl> Iterator for SelectorIter<'a, Impl> {
     type Item = &'a Component<Impl>;
+
+    #[inline]
     fn next(&mut self) -> Option<Self::Item> {
         debug_assert!(self.next_combinator.is_none(),
                       "You should call next_sequence!");
@@ -624,6 +634,7 @@ pub enum Combinator {
 
 impl Combinator {
     /// Returns true if this combinator is a child or descendant combinator.
+    #[inline]
     pub fn is_ancestor(&self) -> bool {
         matches!(*self, Combinator::Child |
                         Combinator::Descendant |
@@ -631,11 +642,13 @@ impl Combinator {
     }
 
     /// Returns true if this combinator is a pseudo-element combinator.
+    #[inline]
     pub fn is_pseudo_element(&self) -> bool {
         matches!(*self, Combinator::PseudoElement)
     }
 
     /// Returns true if this combinator is a next- or later-sibling combinator.
+    #[inline]
     pub fn is_sibling(&self) -> bool {
         matches!(*self, Combinator::NextSibling | Combinator::LaterSibling)
     }
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index f25b93b8dec..27ec1d91338 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -99,14 +99,17 @@ pub struct GeckoDocument<'ld>(pub &'ld structs::nsIDocument);
 impl<'ld> TDocument for GeckoDocument<'ld> {
     type ConcreteNode = GeckoNode<'ld>;
 
+    #[inline]
     fn as_node(&self) -> Self::ConcreteNode {
         GeckoNode(&self.0._base)
     }
 
+    #[inline]
     fn is_html_document(&self) -> bool {
         self.0.mType == structs::root::nsIDocument_Type::eHTML
     }
 
+    #[inline]
     fn quirks_mode(&self) -> QuirksMode {
         self.0.mCompatMode.into()
     }
@@ -144,6 +147,7 @@ impl<'ld> TDocument for GeckoDocument<'ld> {
 pub struct GeckoNode<'ln>(pub &'ln RawGeckoNode);
 
 impl<'ln> PartialEq for GeckoNode<'ln> {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.0 as *const _ == other.0 as *const _
     }
@@ -302,6 +306,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
         self.flattened_tree_parent().and_then(|n| n.as_element())
     }
 
+    #[inline]
     fn opaque(&self) -> OpaqueNode {
         let ptr: usize = self.0 as *const _ as usize;
         OpaqueNode(ptr)
@@ -329,6 +334,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
         }
     }
 
+    #[inline]
     fn can_be_fragmented(&self) -> bool {
         // FIXME(SimonSapin): Servo uses this to implement CSS multicol / fragmentation
         // Maybe this isn’t useful for Gecko?
@@ -397,14 +403,17 @@ impl<'a> Iterator for GeckoChildrenIterator<'a> {
 pub struct GeckoXBLBinding<'lb>(pub &'lb RawGeckoXBLBinding);
 
 impl<'lb> GeckoXBLBinding<'lb> {
+    #[inline]
     fn base_binding(&self) -> Option<Self> {
         unsafe { self.0.mNextBinding.mRawPtr.as_ref().map(GeckoXBLBinding) }
     }
 
+    #[inline]
     fn anon_content(&self) -> *const nsIContent {
         unsafe { self.0.mContent.raw::<nsIContent>() }
     }
 
+    #[inline]
     fn inherits_style(&self) -> bool {
         unsafe { bindings::Gecko_XBLBinding_InheritsStyle(self.0) }
     }
@@ -1024,6 +1033,7 @@ impl<'le> TElement for GeckoElement<'le> {
         }
     }
 
+    #[inline]
     fn as_node(&self) -> Self::ConcreteNode {
         unsafe { GeckoNode(&*(self.0 as *const _ as *const RawGeckoNode)) }
     }
@@ -1080,6 +1090,7 @@ impl<'le> TElement for GeckoElement<'le> {
         get_animation_rule(self, CascadeLevel::Transitions)
     }
 
+    #[inline]
     fn get_state(&self) -> ElementState {
         ElementState::from_bits_truncate(self.get_state_internal())
     }
@@ -1752,6 +1763,7 @@ impl<'le> TElement for GeckoElement<'le> {
 }
 
 impl<'le> PartialEq for GeckoElement<'le> {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.0 as *const _ == other.0 as *const _
     }
@@ -1760,6 +1772,7 @@ impl<'le> PartialEq for GeckoElement<'le> {
 impl<'le> Eq for GeckoElement<'le> {}
 
 impl<'le> Hash for GeckoElement<'le> {
+    #[inline]
     fn hash<H: Hasher>(&self, state: &mut H) {
         (self.0 as *const _).hash(state);
     }
@@ -1902,6 +1915,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
         }
     }
 
+    #[inline]
     fn is_root(&self) -> bool {
         unsafe {
             Gecko_IsRootElement(self.0)