Manchester Free Software

Manchester Free Software

Manchester Free Software

Title: Manchester Free Software
Location: MadLab
Description: The purpose of Manchester Free Software is to promote the Free Software philosophy.
Date: 18-03-2014
Start Time: 19:00
End Time: 21:00

This meeting will be a talk with Q&A.

The GNU Compiler Collection (GCC) is 28 years old this year.
Originally a C compiler, it now handles many languages (8 in theofficial distribution) and has been ported to many architectures (nearly50 in the official distribution). Alongside the compiler are low level binary utilities (assembler, disassembler, linker, profiler, etc.) and a source level debugger (GDB). At 5 million lines of code, GCC is the third largest program in any GNU/Linux system.

In this talk we’ll look at how to best use the tool chain. Starting with official distributions, we’ll look at what is needed to build your own version from source code. We’ll then explore what it takes to modify the tool chain, to port it to a new architecture, to test it, and ultimately to have your code accepted into the official FSF distribution.

We’ll also look at some of the more unusual uses of the tool chain. Its porting to new chips during the design phase to test the hardware design before spinning silicon. How approaches such as iterative compilation and genetic algorithms can double performance compared to -O3. And finally how compilers can use machine learning to work out the best optimizations for your program and even optimize for energy efficiency.

Throughout the talks we’ll use practical examples from both native compilers (for Intel and ARM) and for cross compilers (such as Atmel AVR and Adapteva Epiphany). We’ll also demonstrate the low cost free hardware energy measurement board used to optimize for energy efficiency.


Dr Jeremy Bennett is Chief Executive of Embecosm, an free/libre and open source software consultancy specializing in tool chain development and silicon chip modelling. A former academic he is author of “Introduction to Compiling Techniques” (McGraw-Hill 1990, 1995, 2003).

Joern Rennecke, who leads GCC development for Embecosm, will take questions at the end of the talk. Joern is one of the leading developers of GCC, a project to which he has been contributing for nearly 20 years. He has been responsible for the Renesas SH, OpenRISC 1000, Synopsys ARC ports and most recently has been developing the Atmel AVR and Adapteva Epiphany implementations.

Embecosm are currently hiring both trainee and experienced compiler
developers. Details at


The meeting will be followed by informal discussion and socialising in the bar opposite, Common. There are soft drinks available and there is no pressure to consume alcohol.


The meeting will take place at the usual venue of Madlab, details above. Ring the bell beside the door to be let in. The venue provides wifi.


Around the venue there are parking meter bays that become zero cost after 8pm on Tuesday so you will have to pay up until then and the maximum stay is 2 hours BUT MAKE SURE YOU VERIFY ALL THIS on parking.

There are paid parking lots around the venue, they are marked by a blue P in this OpenStreetMap centred on MadLab. Most of those parking lots are owned by NCP.

If you can’t decide otherwise then park in Manchester Arndale.

Public Transport

Manchester Victoria (MCV) train station, Shudehill tram and bus station, and Manchester Piccadilly bus station are all fairly close to Madlab,see OpenStreetMap centred on MadLab.

Manchester Piccadilly (MAN) train station and Manchester Central Coach Station are not too far away either.

More Information

Information about Manchester Free Software can be found on the
Manchester Free Software pages on LibrePlanet.