DUPQ

Broadcast indexed element within each quadword vector segment (unpredicated)

Unconditionally broadcast the indexed element within each 128-bit source vector segment to all elements of the corresponding destination vector segment. This instruction is unpredicated.

The immediate element index is in the range of 0 to 15 (bytes), 7 (halfwords), 3 (words) or 1 (doublewords).

Encoding: SVE2

Variants: FEAT_SVE2p1 || FEAT_SME2p1 (FEAT_SVE2p1 || FEAT_SME2p1)

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	0	0	0	0	1	0	1	0	0	1						0	0	1	0	0	1
											i1	tsz										Zn					Zd

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

Decoding algorithm

if !IsFeatureImplemented(FEAT_SVE2p1) && !IsFeatureImplemented(FEAT_SME2p1) then
    EndOfDecode(Decode_UNDEF);
if tsz == '0000' then EndOfDecode(Decode_UNDEF);
constant integer lsb = LowestSetBit(tsz);
constant integer esize = 8 << lsb;
constant bits(5) imm = i1:tsz;
constant integer index = UInt(imm<4:(lsb+1)>);
constant integer n = UInt(Zn);
constant integer d = UInt(Zd);

Operation

CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer segments = VL DIV 128;
constant integer elements = 128 DIV esize;
constant bits(VL) operand = Z[n, VL];
bits(VL) result;
bits(esize) element;

for s = 0 to segments-1
    element = Elem[operand, s * elements + index, esize];
    Elem[result, s, 128] = Replicate(element, 128 DIV esize);

Z[d, VL] = result;

Explanations

<Zd>: Is the name of the destination scalable vector register, encoded in the "Zd" field.
<T>: <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 128 bits, encoded in "i1:tsz".

Operational Notes

If PSTATE.DIT is 1:

• The execution time of this instruction is independent of:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.
• The response of this instruction to asynchronous exceptions does not vary based on:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.