BFloat16 adjust exponent (predicated)
This instruction multiplies the active BFloat16 elements of the first source vector by 2.0 to the power of the signed integer values in the corresponding elements of the second source vector and destructively places the results in the corresponding elements of the first source vector. Inactive elements in the destination vector register remain unmodified. This instruction follows SVE2 non-widening BFloat16 numerical behaviors.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | Pg | Zm | Zdn | ||||||||||
| size | opc | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE_BFSCALE) then EndOfDecode(Decode_UNDEF); end; let g : integer = UInt(Pg); let dn : integer = UInt(Zdn); let m : integer = UInt(Zm);
| <Zdn> |
Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field. |
| <Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
if IsFeatureImplemented(FEAT_SME2) then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled(); end; let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let elements : integer = VL DIV 16; let mask : bits(PL) = P{}(g); let operand1 : bits(VL) = Z{}(dn); let operand2 : bits(VL) = if AnyActiveElement{PL}(mask, 16) then Z{VL}(m) else Zeros{VL}; var result : bits(VL); for e = 0 to elements-1 do let element1 : bits(16) = operand1[e*:(16)]; if ActivePredicateElement{PL}(mask, e, 16) then let element2 : integer = SInt(operand2[e*:(16)]); result[e*:(16)] = BFScale(element1, element2, FPCR()); else result[e*:(16)] = element1; end; end; Z{VL}(dn) = result;
This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:
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