F1CVT, F2CVT

8-bit floating-point convert to half-precision

This instruction converts each even-numbered 8-bit floating-point element of the source vector to half-precision while downscaling the value, and places the results in the overlapping 16-bit elements of the destination vector. 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_SVE2 || FEAT_SME2) && FEAT_FP8)

313029282726252423222120191817161514131211109876543210
0110010100001000001100ZnZd
Lopc

Encoding

F1CVT <Zd>.H, <Zn>.B

Decode for this encoding

if ((!IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME2)) || !IsFeatureImplemented(FEAT_FP8)) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 16; let n : integer = UInt(Zn); let d : integer = UInt(Zd); let s_esize : integer{} = 8; let d_esize : integer{} = 16; let issrc2 : boolean = FALSE;

F2CVT
((FEAT_SVE2 || FEAT_SME2) && FEAT_FP8)

313029282726252423222120191817161514131211109876543210
0110010100001000001101ZnZd
Lopc

Encoding

F2CVT <Zd>.H, <Zn>.B

Decode for this encoding

if ((!IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME2)) || !IsFeatureImplemented(FEAT_FP8)) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 16; let n : integer = UInt(Zn); let d : integer = UInt(Zd); let s_esize : integer{} = 8; let d_esize : integer{} = 16; let issrc2 : boolean = TRUE;

Assembler Symbols

<Zd>

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

<Zn>

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

Operation

CheckFPMREnabled(); if IsFeatureImplemented(FEAT_SME2) then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled(); end; let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let operand : bits(VL) = Z{}(n); var result : bits(VL); for e = 0 to elements-1 do let element : bits(esize) = operand[e*:esize]; let res : bits(d_esize) = FP8ConvertFP(element[s_esize-1:0], issrc2, FPCR(), FPMR()); result[e*:esize] = ZeroExtend{esize}(res); end; Z{VL}(d) = result;


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

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