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https://issues.apache.org/jira/browse/ARROW-8598?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Paddy Horan resolved ARROW-8598.
--------------------------------
Fix Version/s: 1.0.0
Resolution: Fixed
Issue resolved by pull request 7043
[https://github.com/apache/arrow/pull/7043]
> [Rust] simd_compare_op creates buffer of incorrect length when item count is
> not a multiple of T::lanes()
> ---------------------------------------------------------------------------------------------------------
>
> Key: ARROW-8598
> URL: https://issues.apache.org/jira/browse/ARROW-8598
> Project: Apache Arrow
> Issue Type: Bug
> Components: Rust
> Affects Versions: 0.17.0
> Reporter: Yordan Pavlov
> Assignee: Paddy Horan
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.0.0
>
> Time Spent: 1h
> Remaining Estimate: 0h
>
> the simd_compare_op function defined here
> [https://github.com/apache/arrow/blob/master/rust/arrow/src/compute/kernels/comparison.rs#L229]
> appears to only work correctly when item count is a multiple of T::lanes().
> Otherwise the resulting boolean array is created with a buffer of incorrect
> length and subsequent binary operations such as compute::and return an error.
> The no_simd_compare_op function defined in the same module does not appear to
> have this problem.
> This bug can be reproduced with the following code:
>
> {code:java}
> fn main() {
> let lanes = Int8Type::lanes();
> println("i8 lanes: {}", lanes); // 64
> // let item_count = 128; // this works because item_count divides by 64
> (lanes) without remainder
> let item_count = 130; // this fails because item_count divides by 64
> (lanes) with remainder
> // item_count = 130 should return error:
> // ComputeError("Buffers must be the same size to apply Bitwise AND.")
>
> // create boolean array
> let mut select_mask: BooleanArray = vec![true; item_count].into();
> // create arrays with i8 values
> let value_array: PrimitiveArray<Int8Type> = vec![1; item_count].into();
> let filter_array: PrimitiveArray<Int8Type> = vec![2; item_count].into();
> // compare i8 arrays and produce a boolean array
> let result_mask = compute::gt_eq(&value_array, &filter_array).unwrap();
> // compare boolean arrays
> select_mask = compute::and(&select_mask, &result_mask).unwrap();
> // print result, should be all false
> println!("select mask: {:?}", select_mask);
> }
> {code}
>
>
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