CPY (scalar)

Copy general-purpose register to vector elements (predicated)

This instruction copies the general-purpose scalar source register to each Active element in the destination vector. Inactive elements in the destination vector register remain unmodified.

This instruction is used by the alias MOV (scalar, predicated).

SVE
(FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
00000101size101000101PgRnZd

Encoding

CPY <Zd>.<T>, <Pg>/M, <R><n|SP>

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let g : integer = UInt(Pg); let n : integer = UInt(Rn); let d : integer = 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 size:

size <T>
00 B
01 H
10 S
11 D
<Pg>

Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.

<R>

Is a width specifier, encoded in size:

size <R>
00 W
01 W
10 W
11 X
<n|SP>

Is the number [0-30] of the general-purpose source register or the name SP (31), encoded in the "Rn" field.

Operation

CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let elements : integer = VL DIV esize; let mask : bits(PL) = P{}(g); var result : bits(VL) = Z{}(d); if AnyActiveElement{PL}(mask, esize) then var operand1 : bits(64); if n == 31 then operand1 = SP{64}(); else operand1 = X{64}(n); end; for e = 0 to elements-1 do if ActivePredicateElement{PL}(mask, e, esize) then result[e*:esize] = operand1[esize-1:0]; end; end; end; Z{VL}(d) = result;

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:


2026-03_rel 2026-03-26 20:48:11

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