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BICS

Bitwise clear predicates, setting the condition flags

This instruction performs a bitwise AND on inverted active elements of the second source predicate with the corresponding elements of the first source predicate and places the results in the corresponding elements of the destination predicate. Inactive elements in the destination predicate register are set to zero. This instruction sets the First (N), None (Z), and !Last (C) condition flags based on the predicate result, and sets the V flag to zero.

Setting the condition flags class

(FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
001001010100Pm01Pg0Pn1Pd
opSo2o3

Encoding

BICS <Pd>.B, <Pg>/Z, <Pn>.B, <Pm>.B

Decode

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant integer esize = 8; constant integer g = UInt(Pg); constant integer n = UInt(Pn); constant integer m = UInt(Pm); constant integer d = UInt(Pd); constant boolean setflags = TRUE;

Assembler Symbols

<Pd>

Is the name of the destination scalable predicate register, encoded in the "Pd" field.

<Pg>

Is the name of the governing scalable predicate register, encoded in the "Pg" field.

<Pn>

Is the name of the first source scalable predicate register, encoded in the "Pn" field.

<Pm>

Is the name of the second source scalable predicate register, encoded in the "Pm" field.

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; constant bits(PL) mask = P[g, PL]; constant bits(PL) operand1 = P[n, PL]; constant bits(PL) operand2 = P[m, PL]; bits(PL) result; constant integer psize = esize DIV 8; for e = 0 to elements-1 constant bit element1 = PredicateElement(operand1, e, esize); constant bit element2 = PredicateElement(operand2, e, esize); if ActivePredicateElement(mask, e, esize) then Elem[result, e, psize] = ZeroExtend(element1 AND (NOT element2), psize); else Elem[result, e, psize] = ZeroExtend('0', psize); if setflags then PSTATE.<N,Z,C,V> = PredTest(mask, result, esize); P[d, PL] = result;

Operational information

If FEAT_SME is implemented and the PE is in Streaming SVE mode, then any subsequent instruction which is dependent on the NZCV condition flags written by this instruction might be significantly delayed.

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