Page 384 - ARM 64 Bit Assembly Language

374 Chapter 10

Name Effect Description
(s|u)shll Vd[] ←≺Vm[] imm Each element of Vm is sign or
zero extended (depending on
<type>) then shifted left by
the immediate value and stored
in the corresponding element of
Vd.
(s|u)qshl{u} Vd[] ← Vm[] imm Each element of Vm is shifted
left by the immediate value and
stored in the corresponding el-
ement of Vd. If the result of
the shift is outside the range of
the destination element, then
the value is saturated. If u was
specified, then the destination is
treated as unsigned for saturation.
Otherwise, it is treated as signed
for saturation.

10.8.1.3 Examples

1 shl v1.4h,v6.4h,#4 // shift each 16-bit word left
2 uqshl v1.16b,v6.16b,#1 // Multiply each byte by two

10.8.2 Vector shift right by immediate

These instructions shift each element in a vector right by an immediate value:

shr Shift Right Immediate,
rshr Shift Right Immediate and Round,
shrn Shift Right Immediate and Narrow,
rshrn Shift Right Immediate Round and Narrow,
sra Shift Right and Accumulate Immediate, and
rsra Shift Right Round and Accumulate Immediate.