Programming with 64-Bit ARM Assembly Language: Single Board Computer Development for Raspberry Pi and Mobile Devices

© Stephen Smith 2020

S. SmithProgramming with 64-Bit ARM Assembly Languagehttps://doi.org/10.1007/978-1-4842-5881-1_14

14. Optimizing Code

Stephen Smith¹ 

(1)

Gibsons, BC, Canada

 

In this chapter, we will look at ways to make our upper-case routine more efficient. We look at some design patterns for more efficient conditional statements, as well as some new ARM instructions that can simplify our code.

Optimizing code often involves thinking outside the box and going beyond finding ways to remove one or two instructions in a loop; we’ll look at a couple of novel ways to greatly improve the upper-case routine.

First of all, we’ll look at a trick to simplify the main if statement.

Optimizing the Upper-Case Routine

Our original upper-case routine implements ...