DUP (scalar)

Broadcast general-purpose register to vector elements (unpredicated)

Unconditionally broadcast the general-purpose scalar source register into each element of the destination vector. This instruction is unpredicated.

Encoding: SVE

Variants: FEAT_SVE || FEAT_SME (FEAT_SVE || FEAT_SME)

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			1	0	0	0	0	0	0	0	1	1	1	0
								size														Rn					Zd

DUP <Zd>.<T>, <R><n|SP>

Decoding algorithm

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
    EndOfDecode(Decode_UNDEF);
constant integer esize = 8 << UInt(size);
constant integer n = UInt(Rn);
constant integer d = UInt(Zd);

Operation

CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer elements = VL DIV esize;
bits(64) operand;
if n == 31 then
    operand = SP[64];
else
    operand = X[n, 64];
bits(VL) result;

for e = 0 to elements-1
    Elem[result, e, esize] = operand;

Z[d, VL] = result;

Explanations

<Zd>: Is the name of the destination scalable vector register, encoded in the "Zd" field.
<T>: <R>: <n|SP>: Is the number [0-30] of the general-purpose source register or the name SP (31), encoded in the "Rn" field.

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.