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NBSL

Bitwise inverted select

This instruction selects bits from the first source vector where the corresponding bit in the third source vector is '1', and from the second source vector where the corresponding bit in the third source vector is '0'. The inverted result is destructively placed in the destination and first source vector. This instruction is unpredicated.

SVE2 class

(FEAT_SVE2 || FEAT_SME)

313029282726252423222120191817161514131211109876543210
00000100111Zm001111ZkZdn
opco2

Encoding

NBSL <Zdn>.D, <Zdn>.D, <Zm>.D, <Zk>.D

Decode

if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant integer m = UInt(Zm); constant integer k = UInt(Zk); constant integer dn = UInt(Zdn);

Assembler Symbols

<Zdn>

Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.

<Zm>

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

<Zk>

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

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant bits(VL) operand1 = Z[dn, VL]; constant bits(VL) operand2 = Z[m, VL]; constant bits(VL) operand3 = Z[k, VL]; Z[dn, VL] = NOT((operand1 AND operand3) OR (operand2 AND NOT(operand3)));

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.

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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