Arm® A64 Instruction Set Architecture: Future Architecture Technologies in the A architecture profile

DUP (indexed)

Broadcast indexed element to vector (unpredicated).

Unconditionally broadcast the indexed source vector element into each element of the destination vector. This instruction is unpredicated.

The immediate element index is in the range of 0 to 63 (bytes), 31 (halfwords), 15 (words), 7 (doublewords) or 3 (quadwords). Selecting an element beyond the accessible vector length causes the destination vector to be set to zero.

This instruction is used by the alias MOV (SIMD&FP scalar, unpredicated).

if !HaveSVE() then UNDEFINED;
bits(7) imm = imm2:tsz;
case tsz of
    when '00000' UNDEFINED;
    when '10000' esize = 128; index = UInt(imm<6:5>);
    when 'x1000' esize = 64;  index = UInt(imm<6:4>);
    when 'xx100' esize = 32;  index = UInt(imm<6:3>);
    when 'xxx10' esize = 16;  index = UInt(imm<6:2>);
    when 'xxxx1' esize = 8;   index = UInt(imm<6:1>);
integer n = UInt(Zn);
integer d = UInt(Zd);

Assembler Symbols

Alias Conditions

CheckSVEEnabled();
integer elements = VL DIV esize;
bits(VL) operand1 = Z[n];
bits(VL) result;
bits(esize) element;

if index >= elements then
    element = Zeros();
else
    element = Elem[operand1, index, esize];
result = Replicate(element);

Z[d] = result;