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).

313029282726252423222120191817161514131211109876543210
00000101imm21tsz001000ZnZd

DUP <Zd>.<T>, <Zn>.<T>[<imm>]

if !HaveSVE() && !HaveSME() then UNDEFINED; if tsz == '00000' then UNDEFINED; constant integer lsb = LowestSetBit(tsz); constant integer esize = 8 << lsb; constant bits(7) imm = imm2:tsz; constant integer index = UInt(imm<6:(lsb+1)>); integer n = UInt(Zn); integer d = UInt(Zd);

Assembler Symbols

<Zd>

Is the name of the destination scalable vector register, encoded in the "Zd" field.

<T>

Is the size specifier, encoded in tsz:

tsz <T>
00000 RESERVED
xxxx1 B
xxx10 H
xx100 S
x1000 D
10000 Q
<Zn>

Is the name of the source scalable vector register, encoded in the "Zn" field.

<imm>

Is the immediate index, in the range 0 to one less than the number of elements in 512 bits, encoded in "imm2:tsz".

Alias Conditions

AliasIs preferred when
MOV (SIMD&FP scalar, unpredicated)BitCount(imm2:tsz) == 1
MOV (SIMD&FP scalar, unpredicated)BitCount(imm2:tsz) > 1

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(VL) operand1 = Z[n, VL]; bits(VL) result; bits(esize) element; if index >= elements then element = Zeros(esize); else element = Elem[operand1, index, esize]; result = Replicate(element, VL DIV esize); Z[d, VL] = result;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:


Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46

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