This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Single instruction to mask off upper half word of register

Note: This was originally posted on 3rd December 2012 at http://forums.arm.com

Hi,

I've been looking around for a single Arm instruction that takes the word stored in a general purpose register and masks off the upper half word (top 16 bits).

There are probably other ways of doing this, for example:
LDR R1 = 0xFFFF
AND R0, R0, R1

But is there a specific instruction that does this? I was looking at LDRH but this instruction does not accept a register as an operand, only constants.

Thanks!
Jawad

Parents

Simon Craske over 12 years ago

Note: This was originally posted on 3rd December 2012 at http://forums.arm.com

From ARMv6 onwards:

UXTH r0,r0
Before ARMv6:

LSL r0,r0,#16 LSR r0,r0,#16
hth
s.
Cancel
Vote up 0 Vote down

Cancel

Reply

Simon Craske over 12 years ago

Note: This was originally posted on 3rd December 2012 at http://forums.arm.com

From ARMv6 onwards:

UXTH r0,r0
Before ARMv6:

LSL r0,r0,#16 LSR r0,r0,#16
hth
s.
Cancel
Vote up 0 Vote down

Cancel

Children

No data