← Home

SBFIZ

Signed 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 below the bitfield to zero, and the bits above the bitfield to a copy of the most significant bit of the bitfield.

This is an alias of SBFM. This means:

313029282726252423222120191817161514131211109876543210
sf00100110NimmrimmsRnRd
opc

32-bit encoding

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

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

is equivalent to

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

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

64-bit encoding

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

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

is equivalent to

SBFM <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 SBFM gives the operational pseudocode for this instruction.

Operational Information

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


Version 2025.09 — Copyright © 2010-2025 Arm Limited or its affiliates.

This site is provided as a community resource and is NOT affiliated with nor endorsed by Arm Limited.