You copied the Doc URL to your clipboard.

ST1H (scalar plus immediate)

Contiguous store halfwords from vector (immediate index).

Contiguous store of halfwords from elements of a vector register to the memory address generated by a 64-bit scalar base and immediate index in the range -8 to 7 which is multiplied by the vector's in-memory size, irrespective of predication, and added to the base address. Inactive elements are not written to memory.


ST1H { <Zt>.<T> }, <Pg>, [<Xn|SP>{, #<imm>, MUL VL}]

if !HaveSVE() then UNDEFINED;
if size == '00' then UNDEFINED;
integer t = UInt(Zt);
integer n = UInt(Rn);
integer g = UInt(Pg);
integer esize = 8 << UInt(size);
integer msize = 16;
integer offset = SInt(imm4);

Assembler Symbols


Is the name of the scalable vector register to be transferred, encoded in the "Zt" 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 P0-P7, encoded in the "Pg" field.


Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.


Is the optional signed immediate vector offset, in the range -8 to 7, defaulting to 0, encoded in the "imm4" field.


integer elements = VL DIV esize;
bits(64) base;
bits(64) addr;
bits(PL) mask = P[g];
bits(VL) src = Z[t];
constant integer mbytes = msize DIV 8;

if n == 31 then
    if LastActiveElement(mask, esize) >= 0 || 
          ConstrainUnpredictableBool(Unpredictable_CHECKSPNONEACTIVE) then 
    if HaveMTEExt() then SetTagCheckedInstruction(FALSE);
    base = SP[];
    if HaveMTEExt() then SetTagCheckedInstruction(TRUE);
    base = X[n];

addr = base + offset * elements * mbytes;
for e = 0 to elements-1
    if ElemP[mask, e, esize] == '1' then
        Mem[addr, mbytes, AccType_NORMAL] = Elem[src, e, esize]<msize-1:0>;
    addr = addr + mbytes;