mattst88's stuff - Open Source Software and Alternative Architectures

Blog: 06 July 2012 - My time optimizing graphics performance on the OLPC XO 1,75 laptop

Last summer after a year of graduate school, I was looking for an interesting project to work on. After asking around, Chris Ball found me in the #xorg-devel IRC channel and set me up working with One Laptop per Child. I started working with Chris and Jon Nettleton on improving the graphics performance of the ARM-based XO 1.75 laptop. The graphics drivers were in a state of flux, and in a number of cases the Sugar interface felt noticeably slower than on the VIA-powered XO 1.5. We wanted to know why it was slower and how to quantitatively measure graphics performance of real-world applications.

Blog: 17 May 2012 - Optimizing pixman for Loongson: Process and Results

The Lemote Yeeloong is a small notebook that is often the computer of choice for Free Software advocates, including Richard Stallman. It's powered by an 800 MHz STMicroelectronics Loongson 2F processor and has an antiquated Silicon Motion 712 graphics chip. The SM712's acceleration features are pretty subpar for today's standards, and performance of the old XFree86 Acceleration Architecture (XAA) that supports the SM712 has slowly decayed as developers move to support newer hardware and newer acceleration architectures. In short, graphics performance of the SM712 isn't very good with new X servers, so how can we improve it?

Blog: 02 August 2011 - New multilib N32 Gentoo MIPS Stages

Gentoo/MIPS has been in, well, not great shape for quite some time. When I was going through Gentoo recruitment, there were no stages (used for installing Gentoo) newer than 2008, so this was one of the main things I wanted to improve, specifically by creating new N32 ABI stages. Even though the N32 (meaning New 32-bit) ABI was introduced in IRIX in 1996 to replace SGI's o32 (Old 32-bit) ABI, Linux support for N32 has lagged behind until the last few years. Now, I'm pleased to unofficially announce new multilib N32 stages and that we'll be supporting as the preferred ABI.

Blog: 11 April 2010 - My Google Summer of Code proposal

I've been involved with X.Org for a few months now. I want to increase my involvement, and at the same time learn the ropes. I also need something to do this summer–and that's why I've applied to the Google Summer of Code.

Blog: 11 January 2009 - The Case for Open Sourcing Alpha-Optimized Libraries

As long as I've been interested in Alpha hardware, I've been intrigued by Compaq's Alpha-optimized compilers and libraries. In some cases, the compilers produce code multiple times faster than by gcc. The math library, libcpml, contains functions that execute in half the time of their glibc equivalents. Since the abandonment of the Alpha platform, this code has languished. In some cases, the performance gap between Compaq's tools and their open source counterparts has shrunk. In others, the benefits of hand-tuned assembly still shine. This prompted me to contact HP and request the release of the code. They unfortunately concluded that an old MIPS license prevented them from releasing the compilers. I've recently contacted HP once again to persuade them to release libcpml and libots as free software, as libraries containing nothing but hand-tuned Alpha assembly could not be encumbered by this license. I also attached the following benchmarks as evidence of why this code is still valuable so many years after it was written.