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Home > NEON and VFP Programming > NEON shift instructions > V{Q}{R}SHL (by signed variable) |

`VSHL`

(Vector Shift Left by signed variable) takes
each element in a vector, shifts them by a value from the least
significant byte of the corresponding element of a second vector,
and places the results in the destination vector. If the shift value
is positive, the operation is a left shift. Otherwise, it is a right
shift.

The results can be optionally saturated, rounded, or both. The sticky QC flag (FPSCR bit[27]) is set if saturation occurs.

V{Q}{R}SHL{}.`cond`

{`datatype`

},`Qd`

,`Qm`

`Qn`

V{Q}{R}SHL{}.`cond`

{`datatype`

},`Dd`

,`Dm`

`Dn`

where:

`Q`

if present, indicates that If any of the results overflow, they are saturated.

`R`

if present, indicates that each result is rounded. Otherwise, each result is truncated.

`cond`

is an optional condition code.

`datatype`

must be one of

`S8`

,`S16`

,`S32`

,`S64`

,`U8`

,`U16`

,`U32`

, or`U64`

.,`Qd`

,`Qm`

`Qn`

are the destination vector, the first operand vector, and the second operand vector, for a quadword operation.

,`Dd`

,`Dm`

`Dn`

are the destination vector, the first operand vector, and the second operand vector, for a doubleword operation.

- Reference