INCP (scalar)

Increment scalar by count of true predicate elements

Counts the number of true elements in the source predicate and then uses the result to increment the scalar destination.

Encoding: SVE

Variants: FEAT_SVE || FEAT_SME (FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
001001011011001000100
sizeopDopc2PmRdn

INCP <Xdn>, <Pm>.<T>

Decoding algorithm

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
    EndOfDecode(Decode_UNDEF);
constant integer esize = 8 << UInt(size);
constant integer m = UInt(Pm);
constant integer dn = UInt(Rdn);

Operation

CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = VL DIV esize;
constant bits(64) operand1 = X[dn, 64];
constant bits(PL) operand2 = P[m, PL];
integer count = 0;

for e = 0 to elements-1
    if ActivePredicateElement(operand2, e, esize) then
        count = count + 1;

X[dn, 64] = operand1 + count;

Explanations

<Xdn>: Is the 64-bit name of the source and destination general-purpose register, encoded in the "Rdn" field.
<Pm>: Is the name of the source scalable predicate register, encoded in the "Pm" field.
<T>:

Operational Notes

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.