F1CVT, F2CVT

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

This instruction converts each 8-bit floating-point element of the source vector to half-precision while downscaling the value, and places the results in the corresponding 16-bit elements of the destination vectors. F1CVT scales the values by 2-UInt(FPMR.LSCALE[3:0]). F2CVT scales the values by 2-UInt(FPMR.LSCALE2[3:0]). The 8-bit floating-point encoding format for F1CVT is selected by FPMR.F8S1. The 8-bit floating-point encoding format for F2CVT is selected by FPMR.F8S2.

This instruction is unpredicated.

It has encodings from 2 classes: F1CVT and F2CVT

F1CVT
(FEAT_SME2 && FEAT_FP8)

313029282726252423222120191817161514131211109876543210
1100000100100110111000ZnZd0
opcL

Encoding

F1CVT { <Zd1>.H-<Zd2>.H }, <Zn>.B

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) || !IsFeatureImplemented(FEAT_FP8) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn); let d : integer = UInt(Zd:: '0'); let issrc2 : boolean = FALSE;

F2CVT
(FEAT_SME2 && FEAT_FP8)

313029282726252423222120191817161514131211109876543210
1100000110100110111000ZnZd0
opcL

Encoding

F2CVT { <Zd1>.H-<Zd2>.H }, <Zn>.B

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) || !IsFeatureImplemented(FEAT_FP8) then EndOfDecode(Decode_UNDEF); end; let n : integer = UInt(Zn); let d : integer = UInt(Zd:: '0'); let issrc2 : boolean = TRUE;

Assembler Symbols

<Zd1>

Is the name of the first scalable vector register of the destination multi-vector group, encoded as "Zd" times 2.

<Zd2>

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

<Zn>

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

Operation

CheckFPMREnabled(); CheckStreamingSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV 8; let operand : bits(VL) = Z{}(n); var result : bits(2*VL); for e = 0 to elements-1 do let element : bits(8) = operand[e*:8]; result[e*:16] = FP8ConvertFP(element, issrc2, FPCR(), FPMR()); end; Z{VL}(d+0) = result[VL-1:0]; Z{VL}(d+1) = result[2*VL-1:VL];


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

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