PTRUE (predicate as counter)

Initialise predicate-as-counter to all active

Set the destination predicate as all-active elements, using the predicate-as-counter encoding.

Encoding: SVE2

Variants: FEAT_SME2 || FEAT_SVE2p1 (FEAT_SME2 || FEAT_SVE2p1)

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			1	0	0	0	0	0	0	1	1	1	1	0	0	0	0	0	0	1	0
								size																					PNd

PTRUE <PNd>.<T>

Decoding algorithm

if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then
    EndOfDecode(Decode_UNDEF);
constant integer esize = 8 << UInt(size);
constant integer d = UInt('1':PNd);

Operation

if IsFeatureImplemented(FEAT_SVE2p1) then CheckSVEEnabled(); else CheckStreamingSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = VL DIV esize;
constant bits(PL) result = EncodePredCount(esize, elements, elements, FALSE, PL);
P[d, PL] = result;

Explanations

<PNd>: Is the name of the destination scalable predicate register PN8-PN15, with predicate-as-counter encoding, encoded in the "PNd" field.
<T>:

Operational Notes

If PSTATE.DIT is 1:

• The execution time of this instruction is independent of:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.
• The response of this instruction to asynchronous exceptions does not vary based on:
  • The values of the data supplied in any of its registers.
  • The values of the NZCV flags.