RealView Compilation Tools Assembler Guide: 3.6.6. Register‑relative and program‑relative expressions

3.6.6. Register-relative and program-relative expressions

A register-relative expression evaluates to a named register plus or minus a numeric constant (see MAP).

A program-relative expression evaluates to the Program Counter (PC), plus or minus a numeric constant. It is normally a label combined with a numeric expression.

Note

The value used in program-relative addresses is:

the address of the instruction following the instruction being executed
OR 0xFFFFFFFC (this makes no difference in ARM code)
plus or minus the numeric constant.

Example

        LDR     r4,=data+4*n    ; n is an assembly-time variable
        ; code
        MOV     pc,lr
data    DCD     value0
        ; n-1 DCD directives
        DCD     valuen          ; data+4*n points here
        ; more DCD directives

Copyright © 2002-2007 ARM Limited. All rights reserved.	ARM DUI 0204H
Non-Confidential
PDF version