LD1RQD (scalar plus scalar)
Contiguous load and replicate two doublewords (scalar index)
Load two contiguous doublewords to elements of a short, 128-bit (quadword) vector from the memory address generated by a 64-bit scalar base address and scalar index which is multiplied by 8 and added to the base address.
Inactive elements will not cause a read from Device memory or signal a fault, and are set to zero. The resulting short vector is then replicated to fill the long destination vector. Only the first two predicate elements are used and higher numbered predicate elements are ignored.
Green
True
True
True
1
0
1
0
0
1
0
1
1
0
0
0
0
0
LD1RQD { <Zt>.D }, <Pg>/Z, [<Xn|SP>, <Xm>, LSL #3]
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED;
if Rm == '11111' then UNDEFINED;
constant integer t = UInt(Zt);
constant integer n = UInt(Rn);
constant integer m = UInt(Rm);
constant integer g = UInt(Pg);
constant integer esize = 64;
<Zt>
Is the name of the scalable vector register to be transferred, encoded in the "Zt" field.
<Pg>
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.
<Xn|SP>
Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.
<Xm>
Is the 64-bit name of the general-purpose offset register, encoded in the "Rm" field.
CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = 128 DIV esize;
bits(64) base;
constant bits(PL) mask = P[g, PL]; // low 16 bits only
bits(64) offset;
bits(64) addr;
bits(128) result;
constant integer mbytes = esize DIV 8;
constant boolean contiguous = TRUE;
constant boolean nontemporal = FALSE;
constant boolean tagchecked = TRUE;
constant AccessDescriptor accdesc = CreateAccDescSVE(MemOp_LOAD, nontemporal, contiguous,
tagchecked);
if !AnyActiveElement(mask, esize) then
if n == 31 && ConstrainUnpredictableBool(Unpredictable_CHECKSPNONEACTIVE) then
CheckSPAlignment();
else
if n == 31 then CheckSPAlignment();
base = if n == 31 then SP[] else X[n, 64];
offset = X[m, 64];
addr = AddressAdd(base, UInt(offset) * mbytes, accdesc);
for e = 0 to elements-1
if ActivePredicateElement(mask, e, esize) then
Elem[result, e, esize] = Mem[addr, mbytes, accdesc];
else
Elem[result, e, esize] = Zeros(esize);
addr = AddressIncrement(addr, mbytes, accdesc);
Z[t, VL] = Replicate(result, VL DIV 128);