Initialise predicate from named constraint
Set elements of the destination predicate to true if the element number satisfies the named predicate constraint, or to false otherwise. If the constraint specifies more elements than are available at the current vector length then all elements of the destination predicate are set to false.
The named predicate constraint limits the number of active elements in a single predicate to:
Unspecified or out of range constraint encodings generate an empty predicate or zero element count rather than Undefined Instruction exception. Does not set the condition flags.
| 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 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | pattern | 0 | Pd | ||||||||
| S | |||||||||||||||||||||||||||||||
if !HaveSVE() && !HaveSME() then UNDEFINED; constant integer esize = 8 << UInt(size); integer d = UInt(Pd); boolean setflags = FALSE; bits(5) pat = pattern;
| <Pd> |
Is the name of the destination scalable predicate register, encoded in the "Pd" 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; integer count = DecodePredCount(pat, esize); bits(PL) result; constant integer psize = esize DIV 8; for e = 0 to elements-1 bit pbit = if e < count then '1' else '0'; Elem[result, e, psize] = ZeroExtend(pbit, psize); if setflags then PSTATE.<N,Z,C,V> = PredTest(result, result, esize); P[d, PL] = result;
If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:
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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