Blogs

Before ARMv6, the main synchronisation mechanism was the SWP instruction. SWP has two aspects, in a uniprocessor system it allows the read and write operations not to be interrupted between them.   In…

Once you move beyond short sequences of optimised Arm assembler, the next likely step will be to managing more complex, optimised routines using macros and functions.

This post aims to provide a simple introduction to Arm assembly language.

Ideally caches act as magic make-it-go-faster logic sitting between processor cores and memory banks. But there are cases where cache behaviour must be considered to get the desired result.

This is the first part of a series on how to write SIMD code for Neon using assembly language. It covers getting started with Neon, using it efficiently, and more.

Sitting in the airport at the end of a week's business trip to the US, I reflected back on the week.  It turned out that my colleague on this trip has an even worse sense of direction than myself.…

In this post, we deal with an often encountered problem: input data that is not a multiple of the length of the vectors you want to process.

Arm implements conditional execution using a set of flags which store state information about a previous operation. in this post I shed some light on the operation of these flags.

This post will show you how we can deal with these limitations and how the latest revision of the Arm architecture (Armv7) provides a simple and efficient solution.

In this post, we will look at how to efficiently multiply four-by-four matrices together, an operation frequently used in the world of 3D graphics.

This blog is a tutorial on detecting overflow from MUL.

It was always about the code (and where it would be used!) When I was a software developer I would often find that the project team I was in would try to guess how many devices the code would eventually…

Armv8 deprecates the use of the it instruction to make anything other than a single 16-bit instruction conditional. This affects many of the examples in this post.

This article introduces the shifting operations provided by Neon, and shows how they can be used to convert image data between commonly used color depths.

Version 3.6.0 of Valgrind was released a couple of weeks ago. The largest change this release is the addition of support for Linux running on ARM. Learn more about the release in this blog.

In this post, I will be introducing a few concepts and explain the reasons behind them. In future posts, I will follow up with practical examples.

My previous post provided an introduction to memory access ordering. It did not however, provide any solution to the problem. This post covers barrier use within the Linux kernel.

On June 29, 2007 -- the original iPhone went on sale and unleashed an unrivaled period of creative innovation and destruction in the mobile phone business.  In case you have forgotten, the original iPhone…

I have a confession to make... I started writing this post in November 2011, but in the excitement of the events at the time, I left it unfinished... until today. This morning I stopped at a local supermarket…

Wouldn't it be great if I could transmogrify the PC to become an intelligent network of specialized components? The goal would be to create a much more efficient computation system marrying critical software…

Since you're reading this blog, it's fairly likely you're technically minded and would've heard of contact-less payment cards. These smart-chip enabled cards promise to speed checkout for…