This patch relax the loop condition to process the final batch.

Example:

If and only if length is an integer multiple of step, the original code will miss the last batch of vectorizable data and use the following scalar loop, although the result will be correct.

--- for (int i = 0; i < length - step; i += step)
+++ for (int i = 0; i <= length - step; i += step)

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake