FMLALLTB (vectors)

8-bit floating-point multiply-add long long to single-precision (top bottom)

This 8-bit floating-point multiply-add long-long instruction widens the third 8-bit element of each 32-bit container in the first and second source vectors to single-precision format and multiplies the corresponding elements. The intermediate products are scaled by 2-UInt(FPMR.LSCALE) before being destructively added without intermediate rounding to the single-precision elements of the destination vector that overlap with the corresponding 8-bit floating-point elements in the source vectors. The 8-bit floating-point encoding format for the elements of the first source vector and the second source vector is selected by FPMR.F8S1 and FPMR.F8S2 respectively.

This instruction is unpredicated.

SVE2
(FEAT_FP8FMA)

313029282726252423222120191817161514131211109876543210
01100100001Zm101010ZnZda
TT<1>TT<0>

FMLALLTB <Zda>.S, <Zn>.B, <Zm>.B

if !HaveSVE2FP8FMA() then UNDEFINED; integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda);

Assembler Symbols

<Zda>

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

CheckFPMREnabled(); if IsFeatureImplemented(FEAT_FP8FMA) then CheckSVEEnabled(); else CheckStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV 32; bits(VL) operand1 = Z[n, VL]; bits(VL) operand2 = Z[m, VL]; bits(VL) operand3 = Z[da, VL]; bits(VL) result; for e = 0 to elements-1 bits(8) element1 = Elem[operand1, 4 * e + 2, 8]; bits(8) element2 = Elem[operand2, 4 * e + 2, 8]; bits(32) element3 = Elem[operand3, e, 32]; Elem[result, e, 32] = FP8MulAddFP(element3, element1, element2, FPCR, FPMR); Z[da, VL] = result;

Operational information

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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