2 add, high or low registers – ARM VERSION 1.2 User Manual
Page 212
Thumb Instruction Reference
5-18
Copyright © 2000, 2001 ARM Limited. All rights reserved.
ARM DUI 0068B
5.2.2
ADD, high or low registers
Add values in registers, returning the result to the first operand register.
Syntax
ADD Rd, Rm
where:
Rd
is the destination register. It is also used for the first operand.
Rm
is a register containing the second operand.
Usage
This instruction adds the values in
Rd
and
Rm
, and places the result in
Rd
.
Note
An
ADD Rd,Rm
instruction where both
Rd
and
Rm
are low registers assembles to an
ADD
Rd,Rd,Rm
instruction (see ADD and SUB, low registers on page 5-16).
Be aware of this when looking at disassembly listings.
Condition flags
The N, Z, C, and V condition flags are:
•
updated if both
Rd
and
Rm
are low registers
•
unaffected otherwise.
Architectures
This instruction is available in all T variants of the ARM architecture.
Examples
ADD r12,r4
ADD r10,r11
ADD r0,r8
ADD r2,r4 ; equivalent to ADD r2,r2,r4. Does affect flags.