Set the first active predicate element to true
Sets the first active element in the destination predicate to true, otherwise elements from the source predicate are passed through unchanged. Sets the First (N), None (Z), !Last (C) condition flags based on the predicate result, and the V flag to zero.
| 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 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | Pg | 0 | Pdn | ||||||
| S | |||||||||||||||||||||||||||||||
if !HaveSVE() && !HaveSME() then UNDEFINED; integer esize = 8; integer g = UInt(Pg); integer dn = UInt(Pdn);
| <Pdn> |
Is the name of the source and destination scalable predicate register, encoded in the "Pdn" field. |
| <Pg> |
Is the name of the governing scalable predicate register, encoded in the "Pg" field. |
CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(PL) result = P[dn]; integer first = -1; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' && first == -1 then first = e; if first >= 0 then ElemP[result, first, esize] = '1'; PSTATE.<N,Z,C,V> = PredTest(mask, result, esize); P[dn] = result;
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.
Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41
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