Fix regression on the get/get_mut/get_not_found (#19505)

# Objective

- Partial fix #19504
- As more features were added to Bevy ECS, certain core hot-path
function calls exceeded LLVM's automatic inlining threshold, leading to
significant performance regressions in some cases.



## Solution

- inline more functions.


## Performance
This brought nearly 3x improvement in Windows bench (using Sander's
testing code)

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>

crates/bevy_ecs/src/world/entity_fetch.rs

@@ -200,6 +200,7 @@ unsafe impl WorldEntityFetch for Entity {
     type Mut<'w> = EntityWorldMut<'w>;
     type DeferredMut<'w> = EntityMut<'w>;
 
+    #[inline]
     unsafe fn fetch_ref(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -209,6 +210,7 @@ unsafe impl WorldEntityFetch for Entity {
         Ok(unsafe { EntityRef::new(ecell) })
     }
 
+    #[inline]
     unsafe fn fetch_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -223,6 +225,7 @@ unsafe impl WorldEntityFetch for Entity {
         Ok(unsafe { EntityWorldMut::new(world, self, Some(location)) })
     }
 
+    #[inline]
     unsafe fn fetch_deferred_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -242,6 +245,7 @@ unsafe impl<const N: usize> WorldEntityFetch for [Entity; N] {
     type Mut<'w> = [EntityMut<'w>; N];
     type DeferredMut<'w> = [EntityMut<'w>; N];
 
+    #[inline]
     unsafe fn fetch_ref(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -249,6 +253,7 @@ unsafe impl<const N: usize> WorldEntityFetch for [Entity; N] {
         <&Self>::fetch_ref(&self, cell)
     }
 
+    #[inline]
     unsafe fn fetch_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -256,6 +261,7 @@ unsafe impl<const N: usize> WorldEntityFetch for [Entity; N] {
         <&Self>::fetch_mut(&self, cell)
     }
 
+    #[inline]
     unsafe fn fetch_deferred_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -273,6 +279,7 @@ unsafe impl<const N: usize> WorldEntityFetch for &'_ [Entity; N] {
     type Mut<'w> = [EntityMut<'w>; N];
     type DeferredMut<'w> = [EntityMut<'w>; N];
 
+    #[inline]
     unsafe fn fetch_ref(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -290,6 +297,7 @@ unsafe impl<const N: usize> WorldEntityFetch for &'_ [Entity; N] {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -316,6 +324,7 @@ unsafe impl<const N: usize> WorldEntityFetch for &'_ [Entity; N] {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_deferred_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -335,6 +344,7 @@ unsafe impl WorldEntityFetch for &'_ [Entity] {
     type Mut<'w> = Vec<EntityMut<'w>>;
     type DeferredMut<'w> = Vec<EntityMut<'w>>;
 
+    #[inline]
     unsafe fn fetch_ref(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -349,6 +359,7 @@ unsafe impl WorldEntityFetch for &'_ [Entity] {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -372,6 +383,7 @@ unsafe impl WorldEntityFetch for &'_ [Entity] {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_deferred_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -391,6 +403,7 @@ unsafe impl WorldEntityFetch for &'_ EntityHashSet {
     type Mut<'w> = EntityHashMap<EntityMut<'w>>;
     type DeferredMut<'w> = EntityHashMap<EntityMut<'w>>;
 
+    #[inline]
     unsafe fn fetch_ref(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -404,6 +417,7 @@ unsafe impl WorldEntityFetch for &'_ EntityHashSet {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_mut(
         self,
         cell: UnsafeWorldCell<'_>,
@@ -417,6 +431,7 @@ unsafe impl WorldEntityFetch for &'_ EntityHashSet {
         Ok(refs)
     }
 
+    #[inline]
     unsafe fn fetch_deferred_mut(
         self,
         cell: UnsafeWorldCell<'_>,

crates/bevy_ecs/src/world/entity_ref.rs

@@ -457,6 +457,7 @@ impl<'w> EntityMut<'w> {
     /// - `cell` must have permission to mutate every component of the entity.
     /// - No accesses to any of the entity's components may exist
     ///   at the same time as the returned [`EntityMut`].
+    #[inline]
     pub(crate) unsafe fn new(cell: UnsafeEntityCell<'w>) -> Self {
         Self { cell }
     }
@@ -1010,6 +1011,7 @@ impl<'w> From<EntityWorldMut<'w>> for EntityMut<'w> {
 }
 
 impl<'a> From<&'a mut EntityWorldMut<'_>> for EntityMut<'a> {
+    #[inline]
     fn from(entity: &'a mut EntityWorldMut<'_>) -> Self {
         // SAFETY: `EntityWorldMut` guarantees exclusive access to the entire world.
         unsafe { EntityMut::new(entity.as_unsafe_entity_cell()) }
@@ -1122,6 +1124,7 @@ impl<'w> EntityWorldMut<'w> {
         }
     }
 
+    #[inline(always)]
     fn as_unsafe_entity_cell_readonly(&self) -> UnsafeEntityCell<'_> {
         let location = self.location();
         let last_change_tick = self.world.last_change_tick;
@@ -1134,6 +1137,8 @@ impl<'w> EntityWorldMut<'w> {
             change_tick,
         )
     }
+
+    #[inline(always)]
     fn as_unsafe_entity_cell(&mut self) -> UnsafeEntityCell<'_> {
         let location = self.location();
         let last_change_tick = self.world.last_change_tick;
@@ -1146,6 +1151,8 @@ impl<'w> EntityWorldMut<'w> {
             change_tick,
         )
     }
+
+    #[inline(always)]
     fn into_unsafe_entity_cell(self) -> UnsafeEntityCell<'w> {
         let location = self.location();
         let last_change_tick = self.world.last_change_tick;
@@ -1188,6 +1195,7 @@ impl<'w> EntityWorldMut<'w> {
     }
 
     /// Gets read-only access to all of the entity's components.
+    #[inline]
     pub fn as_readonly(&self) -> EntityRef<'_> {
         EntityRef::from(self)
     }
@@ -1199,6 +1207,7 @@ impl<'w> EntityWorldMut<'w> {
     }
 
     /// Gets non-structural mutable access to all of the entity's components.
+    #[inline]
     pub fn as_mutable(&mut self) -> EntityMut<'_> {
         EntityMut::from(self)
     }