MLA (vectors)

Multiply-add vectors (predicated), writing addend [Zda = Zda + Zn * Zm]

Multiply the corresponding active elements of the first and second source vectors and add to elements of the third source (addend) vector. Destructively place the results in the destination and third source (addend) vector. Inactive elements in the destination vector register remain unmodified.

313029282726252423222120191817161514131211109876543210
00000100size0Zm010PgZnZda
op

MLA <Zda>.<T>, <Pg>/M, <Zn>.<T>, <Zm>.<T>

if !HaveSVE() && !HaveSME() then UNDEFINED; constant integer esize = 8 << UInt(size); integer g = UInt(Pg); integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda); boolean sub_op = FALSE;

Assembler Symbols

<Zda>

Is the name of the third source and destination scalable vector register, encoded in the "Zda" field.

<T>

Is the size specifier, encoded in size:

size <T>
00 B
01 H
10 S
11 D
<Pg>

Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.

<Zn>

Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Zm>

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

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(PL) mask = P[g, PL]; bits(VL) operand1 = if AnyActiveElement(mask, esize) then Z[n, VL] else Zeros(VL); bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m, VL] else Zeros(VL); bits(VL) operand3 = Z[da, VL]; bits(VL) result; for e = 0 to elements-1 if ActivePredicateElement(mask, e, esize) then integer element1 = UInt(Elem[operand1, e, esize]); integer element2 = UInt(Elem[operand2, e, esize]); integer product = element1 * element2; if sub_op then Elem[result, e, esize] = Elem[operand3, e, esize] - product; else Elem[result, e, esize] = Elem[operand3, e, esize] + product; else Elem[result, e, esize] = Elem[operand3, e, esize]; Z[da, VL] = result;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX instruction must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is unpredictable:


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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