Contiguous store non-temporal of halfwords from multiple consecutive vectors (scalar index)
This instruction performs a contiguous non-temporal store of halfwords from elements of two or four consecutive vector registers to the memory address generated by a 64-bit scalar base and scalar index that is added to the base address. After each element access the index value is incremented, but the index register is not updated.
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.
It has encodings from 2 classes: Two registers and Four registers
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Rm | 0 | 0 | 1 | PNg | Rn | Zt | 1 | |||||||||||||
| msz | N | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Rn); let m : integer = UInt(Rm); let g : integer = UInt('1'::PNg); let nreg : integer{} = 2; let t : integer = UInt(Zt::'0'); let esize : integer{} = 16;
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Rm | 1 | 0 | 1 | PNg | Rn | Zt | 0 | 1 | ||||||||||||
| msz | N | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Rn); let m : integer = UInt(Rm); let g : integer = UInt('1'::PNg); let nreg : integer{} = 4; let t : integer = UInt(Zt::'00'); let esize : integer{} = 16;
| <Zt2> |
Is the name of the second scalable vector register to be transferred, encoded as "Zt" times 2 plus 1. |
| <PNg> |
Is the name of the governing scalable predicate register PN8-PN15, with predicate-as-counter encoding, encoded in the "PNg" 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. |
| <Zt4> |
Is the name of the fourth scalable vector register to be transferred, encoded as "Zt" times 4 plus 3. |
if IsFeatureImplemented(FEAT_SVE2p1) then CheckSVEEnabled(); else CheckStreamingSVEEnabled(); end; let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let elements : integer = VL DIV esize; let mbytes : integer{} = esize DIV 8; var offset : bits(64); var base : bits(64); var addr : bits(64); var src : bits(VL); let pred : bits(PL) = P{}(g); let mask : bits(PL * nreg) = CounterToPredicate{}(pred[15:0]); let contiguous : boolean = TRUE; let nontemporal : boolean = TRUE; let transfer : integer = t; let tagchecked : boolean = TRUE; let accdesc : AccessDescriptor = CreateAccDescSVE(MemOp_STORE, nontemporal, contiguous, tagchecked); if !AnyActiveElement{PL*nreg}(mask, esize) then if n == 31 && ConstrainUnpredictableBool(Unpredictable_CHECKSPNONEACTIVE) then CheckSPAlignment(); end; else if n == 31 then CheckSPAlignment(); end; end; base = if n == 31 then SP{64}() else X{64}(n); offset = X{64}(m); addr = AddressAdd(base, UInt(offset) * mbytes, accdesc); for r = 0 to nreg-1 do src = Z{VL}(transfer+r); for e = 0 to elements-1 do if ActivePredicateElement{PL*nreg}(mask, r * elements + e, esize) then Mem{esize}(addr, accdesc) = src[e*:esize]; end; addr = AddressIncrement(addr, mbytes, accdesc); end; end;
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
2026-03_rel 2026-03-26 20:48:11
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