VEXT (byte elements)

Vector Extract extracts elements from the bottom end of the second operand vector and the top end of the first, concatenates them and places the result in the destination vector.

The elements of the vectors are treated as being 8-bit fields. There is no distinction between data types.

The following figure shows an example of the operation of VEXT doubleword operation for imm = 3.

Depending on settings in the CPACR, NSACR, and HCPTR registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be undefined, or trapped to Hyp mode. For more information see Enabling Advanced SIMD and floating-point support.

This instruction is used by the pseudo-instruction VEXT (multibyte elements).

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

A1

if Q == '1' && (Vd<0> == '1' || Vn<0> == '1' || Vm<0> == '1') then UNDEFINED; if Q == '0' && imm4<3> == '1' then UNDEFINED; constant quadword_operation = (Q == '1'); constant integer position = 8 * UInt(imm4); constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm);

T1

if Q == '1' && (Vd<0> == '1' || Vn<0> == '1' || Vm<0> == '1') then UNDEFINED; if Q == '0' && imm4<3> == '1' then UNDEFINED; constant quadword_operation = (Q == '1'); constant integer position = 8 * UInt(imm4); constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm);