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STNT1D (scalar plus immediate, single register)

Contiguous store non-temporal doublewords from vector (immediate index)

This instruction performs a contiguous non-temporal store of doublewords 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 that 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.

A non-temporal store is a hint to the system that this data is unlikely to be referenced again soon.

SVE class

(FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
111001011001imm4111PgRnZt
msz

Encoding

STNT1D { <Zt>.D }, <Pg>, [<Xn|SP>{, #<imm>, MUL VL}]

Decode

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant integer t = UInt(Zt); constant integer n = UInt(Rn); constant integer g = UInt(Pg); constant integer esize = 64; constant integer offset = SInt(imm4);

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.

<imm>

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

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(64) base; bits(64) addr; constant integer mbytes = esize DIV 8; bits(VL) src; constant bits(PL) mask = P[g, PL]; constant boolean contiguous = TRUE; constant boolean nontemporal = TRUE; constant boolean predicated = TRUE; constant boolean tagchecked = n != 31; constant AccessDescriptor accdesc = CreateAccDescSVE(MemOp_STORE, nontemporal, contiguous, predicated, tagchecked); if !AnyActiveElement(mask, esize) then if n == 31 && ConstrainUnpredictableBool(Unpredictable_CHECKSPNONEACTIVE) then CheckSPAlignment(); else if n == 31 then CheckSPAlignment(); src = Z[t, VL]; base = if n == 31 then SP[64] else X[n, 64]; addr = AddressAdd(base, offset * elements * mbytes, accdesc); for e = 0 to elements-1 if ActivePredicateElement(mask, e, esize) then Mem[addr, mbytes, accdesc] = Elem[src, e, esize]; addr = AddressIncrement(addr, mbytes, accdesc);

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.


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