From 06738bff639ee416a2b51a731ba8efe1f90a27f6 Mon Sep 17 00:00:00 2001
From: re0312 <45868716+re0312@users.noreply.github.com>
Date: Tue, 2 Apr 2024 14:02:56 +0800
Subject: [PATCH] Remove unnecessary branch in query iteration (#12844)

# Objective

- Since #10811,Bevy uses `assert `in the hot path of iteration. The
`for_each `method has an assert in the outer loop to help the compiler
remove unnecessary branching in the internal loop.
- However , ` for` style iterations do not receive the same treatment.
it still have a branch check in the internal loop, which could
potentially hurt performance.

## Solution

- use `TableRow::from_u32 ` instead of ` TableRow::from_usize` to avoid
unnecessary branch.

Before


![image](https://github.com/bevyengine/bevy/assets/45868716/f6d2a1ac-2129-48ff-97bf-d86713ddeaaf)



After
----------------------------------------------------------------------------


![image](https://github.com/bevyengine/bevy/assets/45868716/bfe5a9ee-ba6c-4a80-85b0-1c6d43adfe8c)
---
 crates/bevy_ecs/src/storage/table.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_ecs/src/storage/table.rs b/crates/bevy_ecs/src/storage/table.rs
index 8d6b03d1da189..3c06b41b91a48 100644
--- a/crates/bevy_ecs/src/storage/table.rs
+++ b/crates/bevy_ecs/src/storage/table.rs
@@ -56,7 +56,7 @@ impl TableId {
     /// Will panic if the provided value does not fit within a [`u32`].
     #[inline]
     pub const fn from_usize(index: usize) -> Self {
-        assert!(index as u32 as usize == index);
+        debug_assert!(index as u32 as usize == index);
         Self(index as u32)
     }
 
@@ -116,7 +116,7 @@ impl TableRow {
     /// Will panic if the provided value does not fit within a [`u32`].
     #[inline]
     pub const fn from_usize(index: usize) -> Self {
-        assert!(index as u32 as usize == index);
+        debug_assert!(index as u32 as usize == index);
         Self(index as u32)
     }