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.

313029282726252423222120191817161514131211109876543210
10100101100Rm000PgRnZt
msz<1>msz<0>ssz

LD1RQD { <Zt>.D }, <Pg>/Z, [<Xn|SP>, <Xm>, LSL #3]

if !HaveSVE() && !HaveSME() then UNDEFINED; if Rm == '11111' then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Rm); integer g = UInt(Pg); integer esize = 64;

Assembler Symbols

<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.

Operation

CheckSVEEnabled(); integer elements = 128 DIV esize; bits(64) base; bits(PL) mask = P[g]; // low 16 bits only bits(64) offset; bits(128) result; constant integer mbytes = esize DIV 8; if HaveMTEExt() then SetTagCheckedInstruction(TRUE); 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]; offset = X[m]; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' then integer eoff = UInt(offset) + e; bits(64) addr = base + eoff * mbytes; Elem[result, e, esize] = Mem[addr, mbytes, AccType_NORMAL]; else Elem[result, e, esize] = Zeros(); Z[t] = Replicate(result, VL DIV 128);


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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