TESTING: test just special case boolean code

arrow-buffer/src/buffer/ops.rs

@@ -61,6 +61,8 @@ where
 
 /// Apply a bitwise operation `op` to two inputs and return the result as a Buffer.
 /// The inputs are treated as bitmaps, meaning that offsets and length are specified in number of bits.
+///
+/// This is a comment for testing purposes
 pub fn bitwise_bin_op_helper<F>(
     left: &Buffer,
     left_offset_in_bits: usize,
@@ -72,6 +74,30 @@ pub fn bitwise_bin_op_helper<F>(
 where
     F: FnMut(u64, u64) -> u64,
 {
+    // If the underlying buffers are aligned to u64 we can apply the operation directly on the u64 slices
+    // to improve performance.
+    if left_offset_in_bits == 0 && right_offset_in_bits == 0 {
+        unsafe {
+            let (left_prefix, left_u64s, left_suffix) = left.as_slice().align_to::<u64>();
+            let (right_prefix, right_u64s, right_suffix) = right.as_slice().align_to::<u64>();
+            // if there is no prefix or suffix, both buffers are aligned and we can do the operation directly
+            // on u64s
+            // TODO also handle non empty suffixes by processing them separately
+            if left_prefix.is_empty()
+                && right_prefix.is_empty()
+                && left_suffix.is_empty()
+                && right_suffix.is_empty()
+            {
+                let result_u64s = left_u64s
+                    .iter()
+                    .zip(right_u64s.iter())
+                    .map(|(l, r)| op(*l, *r))
+                    .collect::<Vec<u64>>();
+                return result_u64s.into();
+            }
+        }
+    }
+
     let left_chunks = left.bit_chunks(left_offset_in_bits, len_in_bits);
     let right_chunks = right.bit_chunks(right_offset_in_bits, len_in_bits);