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 and I'm taking SBR600 course in 2010 Winter Semester.

Blog @ [[1]]

thlee3 @ FAS2

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

Tyler.lee @ Open Source Seneca Wiki

thlee3@learn.senecac.on.ca

What I need to learn

- rpmbuild
- /usr/lib/rpm/redhat/rpmrc
- /usr/lib/rpm/redhat/macros
- time
- screen
- yumdownloader
- rpm2cpio

Project Plan

Goals for each release:

• 0.1 Determine whether THUMB gives advantage in file size compared to NON-THUMB.
• 0.2 Compare and contrast file sizes between NON-THUMB, THUMB and THUMB2.
• 0.3 Compare the performance of software compiled with THUMB and NON-THUMB

Test results

nled-2.52

Produced RPM: nled-2.52-6.fc12.armv5tel.rpm

Directories and files: 2 directories, 1 file

Binary File: usr/bin/nled

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

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

Project Details

To be added.

Project News

October 8th, 2010 - Project started

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

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