ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

The Instruction Sets
A4.4.5 Packing and unpacking instructions
Table A4-8 lists the packing and unpacking instructions in the ARM and Thumb instruction sets. These are
all available from ARMv6T2 in the Thumb instruction set, and from ARMv6 onwards in the ARM
instruction set.
Table A4-8 Packing and unpacking instructions
Instruction See Operation
Pack Halfword PKH on page A8-234 Combine halfwords
Signed Extend and Add Byte SXTAB on page A8-434 Extend 8 bits to 32 and add
Signed Extend and Add Byte 16 SXTAB16 on page A8-436 Dual extend 8 bits to 16 and add
Signed Extend and Add Halfword SXTAH on page A8-438 Extend 16 bits to 32 and add
Signed Extend Byte SXTB on page A8-440 Extend 8 bits to 32
Signed Extend Byte 16 SXTB16 on page A8-442 Dual extend 8 bits to 16
Signed Extend Halfword SXTH on page A8-444 Extend 16 bits to 32
Unsigned Extend and Add Byte UXTAB on page A8-514 Extend 8 bits to 32 and add
Unsigned Extend and Add Byte 16 UXTAB16 on page A8-516 Dual extend 8 bits to 16 and add
Unsigned Extend and Add Halfword UXTAH on page A8-518 Extend 16 bits to 32 and add
Unsigned Extend Byte UXTB on page A8-520 Extend 8 bits to 32
Unsigned Extend Byte 16 UXTB16 on page A8-522 Dual extend 8 bits to 16
Unsigned Extend Halfword UXTH on page A8-524 Extend 16 bits to 32
A4-14 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B