The analysis of algorithms mostly relies on counting classic elementary operations like additions, multiplications, comparisons, swaps etc. This approach is often sufficient to quantify an algorithm’s efficiency. In some cases, however, features of modern processor architectures like pipelined execution and memory hierarchies have significant impact on running time and need to be taken into acc...

The modern CPU’s design, which is composed of hierarchical memory and SIMD/vectorization capability, governs the potential for algorithms to be transformed into efficient implementations. The release of the AVX-512 changed things radically, and motivated us to search for an efficient sorting algorithm that can take advantage of it. In this paper, we describe the best strategy we have found, whi...

Heapsort, Quicksort and Mergesort are three ingenious sorting algorithms, which deserve special attention. In the past these algorithms were studied in detail, but the study was carried out on old machines and involved cache simulations. Over the years computer architecture has gone through radical changes. Therefore, a study valid on old architectures may not be valid on new architectures. The...

We will analyze the number of comparisons needed to solve the problem of sorting n distinct items into ascending order, and the related problem of selecting the kth smallest item from an unsorted list of n items. Section 1 examines mergesort, an algorithm with excellent worst case performance, and Section 2 examines quicksort, an algorithm with excellent average case performance. Section 3 cont...

This paper introduces Buffered Adaptive Radix (BARsort) that adds two improvements to the well known right-to-left Radix sorting algorithm (Right Radix or just Radix). The first improvement, the adaptive part, is that the size of the sorting digit is adjusted according to the maximum value of the elements in the array. This makes BARsort somewhat faster than ordinary 8-bit Radix sort (Radix8). ...

Sorting is one of the oldest computing problems and is still very important in the age of big data. Various algorithms and implementation techniques have been proposed. In this study, we focus on comparison based, internal sorting algorithms. We created 12 data types of various sizes for experiments and tested extensively various implementations in a single setting. Using some effective techniq...