To Thumb or Not to Thumb

Project Name

To Thumb? or Not to Thumb?

Project Description

Fedora-ARM does not use thumb. The purpose of this project is to discover whether thumb provides any significant savings in terms of code size, whether programs compiled to thumb execute more quickly or more slowly than non-thumb programs on common ARM processors, whether a thumb compilation takes more or less time than non-thumb, and whether there are any other factors that would influence the decision to support thumb. Ultimately, this project should make a recommendation on the use of the thumb instruction set for the Fedora-ARM secondary architecture.

Project Leader(s)

I will be working alone for this project. My name is Tae Hee (Tyler) Lee.

thlee3 @ FAS2

thlee3 @ irc://irc.mozilla.org/seneca

Tyler.lee @ Open Source Seneca Wiki

thlee3@learn.senecac.on.ca

Project Details

To be added.

Resources

ARM Architecture - http://en.wikipedia.org/wiki/ARM_architecture#Thumb

Introduction to ARM thumb - http://www.eetimes.com/discussion/other/4024632/Introduction-to-ARM-thumb

What I need to learn

Pretty much everything from the scratch. It seems like this project requires lots of background information such as RISC, CISC, Instruction set, Register set, different versions of ARM architecture versions, armv5tel and newer ( and better) models and etc.

Project Plan

Goals for each release:

• 0.1
• 0.2
• 0.3

Test results

From a test performed on 2011-11-12 by CTyler:

........ -O2.. -g... -g stripped
nonthumb 48576 98132 37900
thumb... 40563 93107 29932

Project News

October 8th, 2010 - Project started

October 14th, 2010 - Major project page update with more information.