Computers as Components, 2nd Edition

2.2 ARM Processor 69

mode fetches a different value than the other two examples, but ends up with the

same final value for r1 as does auto-indexing.

We have used the ADR pseudo-op to load addresses into registers to access vari-

ables because this leads to simple, easy-to-read code (at least by assembly language

standards). Compilers tend to use other techniques to generate addresses, because

they must deal with global variables and automatic variables.

2.2.3 Flow of Control

The B (branch) instruction is the basic mechanism in ARM for changing the flow of

control.The address that is the destination of the branch is often called the branch

target. Branches ...