PTEST

Set condition flags for predicate

Sets the First (N), None (Z), !Last (C) condition flags based on the predicate source register, and the V flag to zero.

313029282726252423222120191817161514131211109876543210
001001010101000011Pg0Pn00000
S

PTEST <Pg>, <Pn>.B

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8; constant integer g = UInt(Pg); constant integer n = UInt(Pn);

Assembler Symbols

<Pg>

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

<Pn>

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

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant bits(PL) mask = P[g, PL]; constant bits(PL) result = P[n, PL]; PSTATE.<N,Z,C,V> = PredTest(mask, result, esize);

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:

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


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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