FCVT (narrowing, FP32 to FP16)

Multi-vector single-precision convert to half-precision

This instruction converts each element of the two source vectors from single-precision to half-precision floating-point, and places the results in the half-width destination elements.

This instruction follows SME2 floating-point numerical behaviors corresponding to instructions that place their results in one or more SVE Z vectors.

This instruction is unpredicated.

SME2
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
1100000100100000111000Zn0Zd
opN

Encoding

FCVT <Zd>.H, { <Zn1>.S-<Zn2>.S }

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn::'0'); 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 2.

<Zn2>

Is the name of the second scalable vector register of the source multi-vector group, encoded as "Zn" times 2 plus 1.

Operation

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); for e = 0 to elements-1 do let element1 : bits(32) = operand1[e*:32]; let element2 : bits(32) = operand2[e*:32]; let res1 : bits(16) = FPConvertSVE{16, 32}(element1, FPCR()); let res2 : bits(16) = FPConvertSVE{16, 32}(element2, FPCR()); result[e*:16] = res1; result[(elements+e)*:16] = res2; end; Z{VL}(d) = result;


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

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