UBFX

This instruction copies a bitfield of <width> bits starting from bit position <lsb> in the source register to the least significant bits of the destination register, and sets destination bits above the bitfield to zero.

32-bit encoding

(sf == 0 && N == 0)

UBFX <Wd>, <Wn>, #<lsb>, #<width>

is equivalent to

UBFM <Wd>, <Wn>, #<lsb>, #(<lsb>+<width>-1)

and is the preferred disassembly when BFXPreferred(sf, opc<1>, imms, immr).

64-bit encoding

(sf == 1 && N == 1)

UBFX <Xd>, <Xn>, #<lsb>, #<width>

is equivalent to

UBFM <Xd>, <Xn>, #<lsb>, #(<lsb>+<width>-1)

and is the preferred disassembly when BFXPreferred(sf, opc<1>, imms, immr).

Assembler Symbols

<Wd>	Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Wn>	Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field.

<lsb>	For the "32-bit" variant: is the bit number of the lsb of the source bitfield, in the range 0 to 31.
	For the "64-bit" variant: is the bit number of the lsb of the source bitfield, in the range 0 to 63.

<width>	For the "32-bit" variant: is the width of the bitfield, in the range 1 to 32-<lsb>.
	For the "64-bit" variant: is the width of the bitfield, in the range 1 to 64-<lsb>.

<Xd>	Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Xn>	Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field.

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
sf	1	0	1	0	0	1	1	0	N	immr						imms						Rn					Rd
	opc

32-bit encoding

64-bit encoding

Assembler Symbols

Operation

Operational Information