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→To Thumb or Not To Thumb?
== To Thumb or Not To Thumb? ==
The core of all ARM processors are designs licensed from [http://www.arm.com ARM Ltd]. There are several different [[:fedora:ARM_architecture#ARM_cores|architecture versions]]; Fedora-ARM targets the armv5tel architecture as a "lowest common denominator" among current ARM chips. This architecture supports a '''thumb''' instruction set, which uses 16-bit instructions instead of 32-bit instructions, leading to a higher code density.
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.