From 18fccd316bd640023b8391b7392d77afa50c7009 Mon Sep 17 00:00:00 2001
From: Martin Larralde <martin.larralde@embl.de>
Date: Sun, 16 Jun 2024 19:45:53 +0200
Subject: [PATCH] Fix incorrect alignment handling in `DenseMatrix`
---
lightmotif/src/dense.rs | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/lightmotif/src/dense.rs b/lightmotif/src/dense.rs
index edae74d..9ec9c98 100644
--- a/lightmotif/src/dense.rs
+++ b/lightmotif/src/dense.rs
@@ -87,7 +87,7 @@ impl<T: Default + Copy, C: Unsigned, A: Unsigned + PowerOfTwo> DenseMatrix<T, C,
// compute offset to aligned memory
m.offset = 0;
- while m.data[m.offset..].as_ptr() as usize % c > 0 {
+ while m.data[m.offset..].as_ptr() as usize & (A::USIZE - 1) > 0 {
m.offset += 1
}
@@ -168,7 +168,7 @@ impl<T: Default + Copy, C: Unsigned, A: Unsigned + PowerOfTwo> DenseMatrix<T, C,
self.data.resize_with((rows + 1) * c, T::default);
// Compute offset to aligned memory
self.offset = 0;
- while self.data[self.offset..].as_ptr() as usize % c > 0 {
+ while self.data[self.offset..].as_ptr() as usize & (A::USIZE - 1) > 0 {
self.offset += 1
}
// Copy data in case alignment offset changed
@@ -232,7 +232,9 @@ impl<T: Default + Copy, C: Unsigned, A: Unsigned + PowerOfTwo> Index<usize>
let c = self.stride();
let row = self.offset + c * index;
debug_assert!(row + C::USIZE <= self.data.len());
- &self.data[row..row + C::USIZE]
+ let row = &self.data[row..row + C::USIZE];
+ debug_assert_eq!(row.as_ptr() as usize & (A::USIZE - 1), 0);
+ row
}
}
@@ -244,7 +246,9 @@ impl<T: Default + Copy, C: Unsigned, A: Unsigned + PowerOfTwo> IndexMut<usize>
let c = self.stride();
let row = self.offset + c * index;
debug_assert!(row + C::USIZE <= self.data.len());
- &mut self.data[row..row + C::USIZE]
+ let row = &mut self.data[row..row + C::USIZE];
+ debug_assert_eq!(row.as_ptr() as usize & (A::USIZE - 1), 0);
+ row
}
}
--
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