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Copy 8-bit floating-point immediate to vector elements (predicated).

Copy a floating-point immediate into each active element in the destination vector. Inactive elements in the destination vector register remain unmodified.

This instruction is used by the alias FMOV (immediate, predicated).



FCPY <Zd>.<T>, <Pg>/M, #<const>

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer g = UInt(Pg);
integer d = UInt(Zd);
bits(esize) imm = VFPExpandImm(imm8);

Assembler Symbols


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

<T> Is the size specifier, encoded in size:
size <T>
01 H
10 S
11 D

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


Is a floating-point immediate value expressable as ±n÷16×2^r, where n and r are integers such that 16 ≤ n ≤ 31 and -3 ≤ r ≤ 4, i.e. a normalized binary floating-point encoding with 1 sign bit, 3-bit exponent, and 4-bit fractional part, encoded in the "imm8" field.


integer elements = VL DIV esize;
bits(PL) mask = P[g];
bits(VL) result = Z[d];

for e = 0 to elements-1
    if ElemP[mask, e, esize] == '1' then
        Elem[result, e, esize] = imm;

Z[d] = result;

Operational information

This instruction might be immediately preceded in program order by a MOVPRFX instruction that conforms to all of the following requirements, otherwise the behavior of either or both instructions is unpredictable:

  • The MOVPRFX instruction must specify the same destination register as this instruction.
  • The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.
The MOVPRFX instructions that can be used with this instruction are as follows:
  • An unpredicated MOVPRFX instruction.
  • A predicated MOVPRFX instruction using the same governing predicate register and source element size as this instruction.