BFMMLA

BFloat16 floating-point matrix multiply-accumulate into 2×2 matrices

If FEAT_EBF16 is not implemented or FPCR.EBF is 0, this instruction:

If FEAT_EBF16 is implemented and FPCR.EBF is 1, then this instruction:

Irrespective of FEAT_EBF16 and FPCR.EBF, this instruction:

This instruction is unpredicated and vector length agnostic.

ID_AA64ZFR0_EL1.BF16 indicates whether this instruction is implemented.

This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.

SVE
(FEAT_BF16)

313029282726252423222120191817161514131211109876543210
01100100011Zm111001ZnZda

BFMMLA <Zda>.S, <Zn>.H, <Zm>.H

if !IsFeatureImplemented(FEAT_SVE) || !IsFeatureImplemented(FEAT_BF16) then UNDEFINED; constant integer n = UInt(Zn); constant integer m = UInt(Zm); constant 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

CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer segments = VL DIV 128; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[m, VL]; constant bits(VL) operand3 = Z[da, VL]; bits(VL) result; bits(128) op1, op2; bits(128) res, addend; for s = 0 to segments-1 op1 = Elem[operand1, s, 128]; op2 = Elem[operand2, s, 128]; addend = Elem[operand3, s, 128]; res = BFMatMulAdd(addend, op1, op2, FPCR); Elem[result, s, 128] = res; Z[da, VL] = result;

Operational information

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


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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