Set scalar to count of true predicate elements
Counts the number of active and true elements in the source predicate and places the scalar result in the destination general-purpose register. Inactive predicate elements are not counted.
| 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 | size | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | Pg | 0 | Pn | Rd | |||||||||||
if !HaveSVE() && !HaveSME() then UNDEFINED; constant integer esize = 8 << UInt(size); integer g = UInt(Pg); integer n = UInt(Pn); integer d = UInt(Rd);
| <Xd> |
Is the 64-bit name of the destination general-purpose register, encoded in the "Rd" field. |
| <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. |
| <T> |
Is the size specifier,
encoded in
|
CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(PL) mask = P[g, PL]; bits(PL) operand = P[n, PL]; bits(64) sum = Zeros(64); for e = 0 to elements-1 if ActivePredicateElement(mask, e, esize) && ActivePredicateElement(operand, e, esize) then sum = sum + 1; X[d, 64] = sum;
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 general-purpose register written by this instruction might be significantly delayed.
Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46
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