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Register shift operations move the bits in a register left or right by a specified number of bits, called the shift length.

Register shift can be performed:

- Directly by the instructions
`ASR`

,`LSR`

,`LSL`

,`ROR`

, and`RRX`

, and the result is written to a destination register. - During the calculation of
`Operand2`

by the instructions that specify the second operand as a register with shift. The result is used by the instruction.

The permitted shift lengths depend on the shift type and the
instruction, see the individual instruction description or the flexible
second operand description. If the shift length is 0, no shift occurs.
Register shift operations update the carry flag except when the
specified shift length is 0.

Arithmetic shift right by n bits moves the left-hand 32-n bits of a register to the right
by n places, into the right-hand 32-n bits of the result. It copies the original bit[31] of
the register into the left-hand n bits of the result.

You can use the ^{n}, with the result
being rounded towards negative-infinity.

`ASR #``n`

operation to divide the value in
the register `Rm`

by 2When the instruction is

`ASRS`

or when ```
ASR
#
````n`

is used in `Operand2`

with the
instructions `MOVS`

, `MVNS`

, `ANDS`

,
`ORRS`

, `ORNS`

, `EORS`

,
`BICS`

, `TEQ`

or `TST`

, the carry flag is
updated to the last bit shifted out, bit[`n`

-1], of the register
`Rm`

.-
If
`n`

is 32 or more, then all the bits in the result are set to the value of bit[31] of`Rm`

. -
If
`n`

is 32 or more and the carry flag is updated, it is updated to the value of bit[31] of`Rm`

.

Logical shift right by n bits moves the left-hand 32-n bits of a register to the right by n
places, into the right-hand 32-n bits of the result. It sets the left-hand n bits of the
result to 0.

You can use the ^{n}, if the value is
regarded as an unsigned integer.

`LSR #``n`

operation to divide the value in
the register `Rm`

by 2When the instruction is

`LSRS`

or when```
LSR
#
````n`

is used in `Operand2`

with the
instructions `MOVS`

, `MVNS`

, `ANDS`

,
`ORRS`

, `ORNS`

, `EORS`

,
`BICS`

, `TEQ`

or `TST`

, the carry flag is
updated to the last bit shifted out, bit[`n`

-1], of the register
`Rm`

.-
If
`n`

is 32 or more, then all the bits in the result are cleared to 0. -
If
`n`

is 33 or more and the carry flag is updated, it is updated to 0.

Logical shift left by n bits moves the right-hand 32-n bits of a register to the left by n
places, into the left-hand 32-n bits of the result. It sets the right-hand

`n`

bits of the result to 0.You can use the ^{n}, if the value is
regarded as an unsigned integer or a two’s complement signed integer. Overflow can occur
without warning.

`LSL #``n`

operation to multiply the value
in the register `Rm`

by 2When the instruction is

`LSLS`

or when ```
LSL
#
````n`

, with non-zero `n`

, is used in
`Operand2`

with the instructions `MOVS`

,
`MVNS`

, `ANDS`

, `ORRS`

,
`ORNS`

, `EORS`

, `BICS`

, `TEQ`

or
`TST`

, the carry flag is updated to the last bit shifted out,
bit[`32`

-`n`

], of the register `Rm`

.
These instructions do not affect the carry flag when used with LSL
#0.-
If
`n`

is 32 or more, then all the bits in the result are cleared to 0. -
If
`n`

is 33 or more and the carry flag is updated, it is updated to 0.

Rotate right by n bits moves the left-hand 32-n bits of a register to the right by n
places, into the right-hand 32-n bits of the result. It also moves the right-hand n bits of
the register into the left-hand n bits of the result.

When the instruction is

`RORS`

or when ```
ROR
#
````n`

is used in `Operand2`

with the
instructions `MOVS`

, `MVNS`

, `ANDS`

,
`ORRS`

, `ORNS`

, `EORS`

,
`BICS`

, `TEQ`

or `TST`

, the carry flag is
updated to the last bit rotation, bit[`n`

-1], of the register
`Rm`

.-
If
`n`

is 32, then the value of the result is same as the value in`Rm`

, and if the carry flag is updated, it is updated to bit[31] of`Rm`

. -
`ROR`

with shift length,`n`

, more than 32 is the same as`ROR`

with shift length`n`

-32.

Rotate right with extend moves the bits of a register to the right by one bit. It copies
the carry flag into bit[31] of the result.

When the instruction is

`RRXS`

or when RRX is used in
`Operand2`

with the instructions `MOVS`

,
`MVNS`

, `ANDS`

, `ORRS`

,
`ORNS`

, `EORS`

, `BICS`

, `TEQ`

or
`TST`

, the carry flag is updated to bit[0] of the register
`Rm`

.