FCVT (narrowing, FP32 to FP8)

Multi-vector single-precision convert to 8-bit floating-point

This instruction converts each single-precision element of the four source vectors to 8-bit floating-point while scaling the value by 2SInt(FPMR.NSCALE), and places the results in the quarter-width elements of the destination vector. The 8-bit floating-point encoding format is selected by FPMR.F8D.

This instruction is unpredicated.

SME2
(FEAT_SME2 && FEAT_FP8)

313029282726252423222120191817161514131211109876543210
1100000100110100111000Zn00Zd
N

Encoding

FCVT <Zd>.B, { <Zn1>.S-<Zn4>.S }

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) || !IsFeatureImplemented(FEAT_FP8) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn::'00'); let d : integer = UInt(Zd);

Assembler Symbols

<Zd>

Is the name of the destination scalable vector register, encoded in the "Zd" field.

<Zn1>

Is the name of the first scalable vector register of the source multi-vector group, encoded as "Zn" times 4.

<Zn4>

Is the name of the fourth scalable vector register of the source multi-vector group, encoded as "Zn" times 4 plus 3.

Operation

CheckFPMREnabled(); CheckStreamingSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV 32; var result : bits(VL); let operand1 : bits(VL) = Z{}(n+0); let operand2 : bits(VL) = Z{}(n+1); let operand3 : bits(VL) = Z{}(n+2); let operand4 : bits(VL) = Z{}(n+3); for e = 0 to elements-1 do let element1 : bits(32) = operand1[e*:32]; let element2 : bits(32) = operand2[e*:32]; let element3 : bits(32) = operand3[e*:32]; let element4 : bits(32) = operand4[e*:32]; result[(0*elements + e)*:8] = FPConvertFP8{8, 32}(element1, FPCR(), FPMR()); result[(1*elements + e)*:8] = FPConvertFP8{8, 32}(element2, FPCR(), FPMR()); result[(2*elements + e)*:8] = FPConvertFP8{8, 32}(element3, FPCR(), FPMR()); result[(3*elements + e)*:8] = FPConvertFP8{8, 32}(element4, FPCR(), FPMR()); end; Z{VL}(d) = result;


2026-03_rel 2026-03-26 20:48:11

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