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UBFIZ

Unsigned bitfield insert in zeros

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

This is an alias of UBFM. This means:

313029282726252423222120191817161514131211109876543210
sf10100110NimmrimmsRnRd
opc

32-bit encoding

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

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

is equivalent to

UBFM <Wd>, <Wn>, #(-<lsb> MOD 32), #(<width>-1)

and is the preferred disassembly when UInt(imms) < UInt(immr).

64-bit encoding

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

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

is equivalent to

UBFM <Xd>, <Xn>, #(-<lsb> MOD 64), #(<width>-1)

and is the preferred disassembly when UInt(imms) < UInt(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 destination bitfield, in the range 0 to 31.

For the "64-bit" variant: is the bit number of the lsb of the destination 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.

Operation

The description of UBFM gives the operational pseudocode for this instruction.

Operational Information

The description of UBFM gives the operational information for this instruction.


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