Counting the digits of 64-bit integers

The blog post by Daniel Lemire discusses efficient methods for counting the number of decimal digits in 64-bit integers. It highlights the challenge of computing logarithms in base 10 quickly, given that computers operate in base 2. Lemire presents a classical method for 32-bit integers that utilizes a lookup table and the integer logarithm in base 2. He then extends this approach to 64-bit integers, providing both a conventional and a faster alternative method. The conventional method uses a larger lookup table to determine the number of digits based on the logarithm, while the alternative method employs a more complex 128-bit lookup table to achieve faster results. The post emphasizes the importance of these techniques in software performance, particularly in applications where digit counting is frequently required.

- Efficient digit counting for 64-bit integers is crucial for software performance.

- The methods discussed utilize logarithmic calculations and lookup tables for speed.

- The post provides both conventional and alternative approaches for counting digits.

- Techniques are applicable to both 32-bit and 64-bit integers, with adaptations for each.

- The focus is on optimizing performance in computational tasks involving large integers.