SMLALL (multiple vectors)

Multi-vector signed integer multiply-add long-long

This signed integer multiply-add long-long instruction multiplies each signed 8-bit or 16-bit element in the two or four first source vectors with each signed 8-bit or 16-bit element in the one, two, or four second source vectors, widens each product to 32-bits or 64-bits and destructively adds these values to the corresponding 32-bit or 64-bit elements of the ZA quad-vector groups.

The quad-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 quad-vector groups respectively. The vector group symbol is preferred for disassembly, but optional in assembler source code.

This instruction is unpredicated.

ID_AA64SMFR0_EL1.I16I64 indicates whether the 16-bit integer variant is implemented.

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

Two ZA quad-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
110000011sz1Zm00Rv000Zn00000o1
US

SMLALL ZA.<T>[<Wv>, <offs1>:<offs4>{, VGx2}], { <Zn1>.<Tb>-<Zn2>.<Tb> }, { <Zm1>.<Tb>-<Zm2>.<Tb> }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; if sz == '1' && !IsFeatureImplemented(FEAT_SME_I16I64) then UNDEFINED; constant integer esize = 32 << UInt(sz); constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'0'); constant integer m = UInt(Zm:'0'); constant integer offset = UInt(o1:'00'); constant integer nreg = 2;

Four ZA quad-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
110000011sz1Zm010Rv000Zn000000o1
US

SMLALL ZA.<T>[<Wv>, <offs1>:<offs4>{, VGx4}], { <Zn1>.<Tb>-<Zn4>.<Tb> }, { <Zm1>.<Tb>-<Zm4>.<Tb> }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; if sz == '1' && !IsFeatureImplemented(FEAT_SME_I16I64) then UNDEFINED; constant integer esize = 32 << UInt(sz); constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'00'); constant integer m = UInt(Zm:'00'); constant integer offset = UInt(o1:'00'); constant integer nreg = 4;

Assembler Symbols

<T>

Is the size specifier, encoded in sz:

sz <T>
0 S
1 D
<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 "o1" field times 4.

<offs4>

Is the fourth vector select offset, encoded as "o1" field times 4 plus 3.

<Zn1>

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

<Tb>

Is the size specifier, encoded in sz:

sz <Tb>
0 B
1 H
<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 quad-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 quad-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 4); 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 3 constant bits(VL) operand3 = ZAvector[vec + i, VL]; for e = 0 to elements-1 constant integer element1 = SInt(Elem[operand1, 4 * e + i, esize DIV 4]); constant integer element2 = SInt(Elem[operand2, 4 * e + i, esize DIV 4]); 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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