Single-precision convert to BFloat16 (top, predicated)
This instruction converts each active floating-point element of the source vector from single-precision to BFloat16 floating-point, and places the results in the odd-numbered 16-bit elements of the destination vector, leaving the even-numbered elements unchanged. Inactive elements in the destination vector register remain unmodified or are set to zero, depending on whether merging or zeroing predication is selected.
ID_AA64ZFR0_EL1.BF16 indicates whether this instruction is implemented.
It has encodings from 2 classes: Merging and Zeroing
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| 0 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | Pg | Zn | Zd | ||||||||||
| opc | opc2 | ||||||||||||||||||||||||||||||
if ((!IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME)) || !IsFeatureImplemented(FEAT_BF16)) then EndOfDecode(Decode_UNDEF); end; let g : integer = UInt(Pg); let n : integer = UInt(Zn); let d : integer = UInt(Zd); let merging : boolean = TRUE;
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| 0 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | Pg | Zn | Zd | ||||||||||
| opc | opc2 | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2p2) && !IsFeatureImplemented(FEAT_SME2p2) then EndOfDecode(Decode_UNDEF); end; let g : integer = UInt(Pg); let n : integer = UInt(Zn); let d : integer = UInt(Zd); let merging : boolean = FALSE;
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
| <Zn> |
Is the name of the source scalable vector register, encoded in the "Zn" field. |
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let elements : integer = VL DIV 32; let mask : bits(PL) = P{}(g); let operand : bits(VL) = if AnyActiveElement{PL}(mask, 32) then Z{VL}(n) else Zeros{VL}; var result : bits(VL) = Z{}(d); for e = 0 to elements-1 do if ActivePredicateElement{PL}(mask, e, 32) then let element : bits(32) = operand[e*:32]; result[(2*e+1)*:16] = FPConvertBF(element, FPCR()); elsif !merging then result[(2*e+1)*:16] = Zeros{16}; end; end; Z{VL}(d) = result;
2026-03_rel 2026-03-26 20:48:11
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