SMLAL (multiple vectors)

Multi-vector signed integer multiply-add long

This signed integer multiply-add long instruction multiplies each signed 16-bit element in the two or four first source vectors with each signed 16-bit element in the two or four second source vectors, widens each product to 32-bits and destructively adds these values to the corresponding 32-bit elements of the ZA double-vector groups.

The double-vector group within each half of or each quarter of the ZA array is selected by the sum of the vector select register and offset range, modulo half or quarter the number of ZA array vectors.

The vector group symbol, VGx2 or VGx4, indicates that the ZA operand consists of two or four ZA double-vector groups respectively. The vector group symbol is preferred for disassembly, but optional in assembler source code.

This instruction is unpredicated.

It has encodings from 2 classes: Two ZA double-vectors and Four ZA double-vectors

Two ZA double-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001111Zm00Rv010Zn0000off2
US

SMLAL ZA.S[<Wv>, <offs1>:<offs2>{, VGx2}], { <Zn1>.H-<Zn2>.H }, { <Zm1>.H-<Zm2>.H }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 32; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'0'); constant integer m = UInt(Zm:'0'); constant integer offset = UInt(off2:'0'); constant integer nreg = 2;

Four ZA double-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001111Zm010Rv010Zn00000off2
US

SMLAL ZA.S[<Wv>, <offs1>:<offs2>{, VGx4}], { <Zn1>.H-<Zn4>.H }, { <Zm1>.H-<Zm4>.H }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 32; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'00'); constant integer m = UInt(Zm:'00'); constant integer offset = UInt(off2:'0'); constant integer nreg = 4;

Assembler Symbols

<Wv>

Is the 32-bit name of the vector select register W8-W11, encoded in the "Rv" field.

<offs1>

Is the first vector select offset, encoded as "off2" field times 2.

<offs2>

Is the second vector select offset, encoded as "off2" field times 2 plus 1.

<Zn1>

For the two ZA double-vectors variant: is the name of the first scalable vector register of the first source multi-vector group, encoded as "Zn" times 2.

For the four ZA double-vectors variant: is the name of the first scalable vector register of the first source multi-vector group, encoded as "Zn" times 4.

<Zn4>

Is the name of the fourth scalable vector register of the first source multi-vector group, encoded as "Zn" times 4 plus 3.

<Zn2>

Is the name of the second scalable vector register of the first source multi-vector group, encoded as "Zn" times 2 plus 1.

<Zm1>

For the two ZA double-vectors variant: is the name of the first scalable vector register of the second source multi-vector group, encoded as "Zm" times 2.

For the four ZA double-vectors variant: is the name of the first scalable vector register of the second source multi-vector group, encoded as "Zm" times 4.

<Zm4>

Is the name of the fourth scalable vector register of the second source multi-vector group, encoded as "Zm" times 4 plus 3.

<Zm2>

Is the name of the second scalable vector register of the second source multi-vector group, encoded as "Zm" times 2 plus 1.

Operation

CheckStreamingSVEAndZAEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; constant integer vectors = VL DIV 8; constant integer vstride = vectors DIV nreg; constant bits(32) vbase = X[v, 32]; integer vec = (UInt(vbase) + offset) MOD vstride; bits(VL) result; vec = vec - (vec MOD 2); for r = 0 to nreg-1 constant bits(VL) operand1 = Z[n+r, VL]; constant bits(VL) operand2 = Z[m+r, VL]; for i = 0 to 1 constant bits(VL) operand3 = ZAvector[vec + i, VL]; for e = 0 to elements-1 constant integer element1 = SInt(Elem[operand1, 2 * e + i, esize DIV 2]); constant integer element2 = SInt(Elem[operand2, 2 * e + i, esize DIV 2]); constant bits(esize) product = (element1 * element2)<esize-1:0>; Elem[result, e, esize] = Elem[operand3, e, esize] + product; ZAvector[vec + i, VL] = result; vec = vec + vstride;

Operational information

If PSTATE.DIT is 1:


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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