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ST64B

Single-copy Atomic 64-byte Store without Return stores eight 64-bit doublewords from consecutive registers, Xt to X(t+7), to a memory location. The data that is stored is atomic and is required to be 64-byte-aligned.

Integer
(Armv8.7)

313029282726252423222120191817161514131211109876543210
1111100000111111100100RnRt

ST64B <Xt>, [<Xn|SP> {,#0}]

if !HaveFeatLS64() then UNDEFINED;
if Rt<4:3> == '11' || Rt<0> == '1' then UNDEFINED;

integer n = UInt(Rn);
integer t = UInt(Rt);
boolean tag_checked = n != 31;

Assembler Symbols

<Xt>

Is the 64-bit name of the first general-purpose register to be transferred, encoded in the "Rt" field.

<Xn|SP>

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

Operation

CheckLDST64BEnabled();

bits(512) data;
bits(64) address;
bits(64) value;
acctype = AccType_ATOMICLS64;

if HaveMTEExt() then
    SetTagCheckedInstruction(tag_checked);

for i = 0 to 7
    value = X[t+i];
    if BigEndian(acctype) then value = BigEndianReverse(value);
    data<63+64*i:64*i> = value;

if n == 31 then
    CheckSPAlignment();
    address = SP[];
else
    address = X[n];

MemStore64B(address, data, acctype);