SUDOT (multiple and single vector)

Multi-vector signed by unsigned integer dot-product by vector

The signed by unsigned integer dot product instruction computes the dot product of four signed 8-bit integer values held in each 32-bit element of the two or four first source vectors and four unsigned 8-bit integer values in the corresponding 32-bit element of the second source vector. The widened dot product result is destructively added to the corresponding 32-bit element of the ZA single-vector groups. The vector numbers forming the single-vector group within each half of or each quarter of the ZA array are selected by the sum of the vector select register and immediate offset, 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 single-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 single-vectors and Four ZA single-vectors

Two ZA single-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
110000010010Zm0Rv101Zn11off3
U

SUDOT ZA.S[<Wv>, <offs>{, VGx2}], { <Zn1>.B-<Zn2>.B }, <Zm>.B

if !HaveSME2() then UNDEFINED; integer v = UInt('010':Rv); constant integer esize = 32; integer n = UInt(Zn); integer m = UInt('0':Zm); integer offset = UInt(off3); constant integer nreg = 2;

Four ZA single-vectors
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
110000010011Zm0Rv101Zn11off3
U

SUDOT ZA.S[<Wv>, <offs>{, VGx4}], { <Zn1>.B-<Zn4>.B }, <Zm>.B

if !HaveSME2() then UNDEFINED; integer v = UInt('010':Rv); constant integer esize = 32; integer n = UInt(Zn); integer m = UInt('0':Zm); integer offset = UInt(off3); constant integer nreg = 4;

Assembler Symbols

<Wv>

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

<offs>

Is the vector select offset, in the range 0 to 7, encoded in the "off3" field.

<Zn1>

Is the name of the first scalable vector register of the first source multi-vector group, encoded as "Zn".

<Zn4>

Is the name of the fourth scalable vector register of the first source multi-vector group, encoded as "Zn" plus 3 modulo 32.

<Zn2>

Is the name of the second scalable vector register of the first source multi-vector group, encoded as "Zn" plus 1 modulo 32.

<Zm>

Is the name of the second source scalable vector register Z0-Z15, encoded in the "Zm" field.

Operation

CheckStreamingSVEAndZAEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; integer vectors = VL DIV 8; integer vstride = vectors DIV nreg; bits(32) vbase = X[v, 32]; integer vec = (UInt(vbase) + offset) MOD vstride; bits(VL) result; for r = 0 to nreg-1 bits(VL) operand1 = Z[(n+r) MOD 32, VL]; bits(VL) operand2 = Z[m, VL]; bits(VL) operand3 = ZAvector[vec, VL]; for e = 0 to elements-1 bits(esize) sum = Elem[operand3, e, esize]; for i = 0 to 3 integer element1 = SInt(Elem[operand1, 4 * e + i, esize DIV 4]); integer element2 = UInt(Elem[operand2, 4 * e + i, esize DIV 4]); sum = sum + element1 * element2; Elem[result, e, esize] = sum; ZAvector[vec, VL] = result; vec = vec + vstride;


Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46

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