Fix pointer alignment check in get_batch_aligned_raw

Author: InBetweenNames

crates/bevy_ptr/src/batch.rs

@@ -305,19 +305,13 @@ impl<'a, T> ThinSimdAlignedSlicePtr<'a, T> {
 
         let off_ptr = self.ptr.as_ptr().add(index);
 
+        //NOTE: ZSTs may cause this "slice" to point into nothingness.
+        //This sounds dangerous, but won't cause harm as nothing
+        //will actually access anything "in the slice"
+
+        //TODO: when pointer_is_aligned is standardized, we can just use ptr::is_aligned()
         #[cfg(debug_assertions)]
-        if core::mem::size_of::<T>() > 0 {
-            //NOTE: ZSTs may cause this "slice" to point into nothingness.
-            //A "batch" of ZSTs is itself a ZST.
-            //This sounds dangerous, but won't cause harm as nothing
-            //will actually access anything "in the slice".
-            //ZSTs are trivially well aligned, so there is nothing to be checked.
-            //align_offset will probably return MAX for these types which
-            //can throw the test off.
-            //When is_aligned is standardized, we can just use that.
-
-            debug_assert_eq!(off_ptr.align_offset(ALIGN), 0);
-        }
+        debug_assert_eq!(off_ptr as usize % ALIGN, 0);
 
         //SAFETY: off_ptr is not null
         off_ptr as *const AlignedBatchT<T, N, ALIGN>

crates/bevy_ptr/src/lib.rs

@@ -220,13 +220,13 @@ impl<'a, T> ThinSimdAlignedSlicePtr<'a, T> {
     /// `ptr` must be aligned to at least `MAX_SIMD_ALIGNMENT`
     #[inline]
     pub unsafe fn new(ptr: *mut T, _len: usize) -> Self {
+        //NOTE: ZSTs may cause this "slice" to point into nothingness.
+        //This sounds dangerous, but won't cause harm as nothing
+        //will actually access anything "in the slice"
+
+        //TODO: when pointer_is_aligned is standardized, we can just use ptr::is_aligned()
         #[cfg(debug_assertions)]
-        if core::mem::size_of::<T>() > 0 {
-            //NOTE: ZSTs may cause this "slice" to point into nothingness.
-            //This sounds dangerous, but won't cause harm as nothing
-            //will actually access anything "in the slice"
-            debug_assert!(ptr.align_offset(batch::MAX_SIMD_ALIGNMENT) == 0);
-        }
+        debug_assert_eq!(ptr as usize % batch::MAX_SIMD_ALIGNMENT, 0);
 
         Self {
             ptr: NonNull::new_unchecked(ptr),