DECP (scalar) Decrement scalar by count of true predicate elements Counts the number of true elements in the source predicate and then uses the result to decrement the scalar destination. Green False 0 0 1 0 0 1 0 1 1 0 1 1 0 1 1 0 0 0 1 0 0 DECP <Xdn>, <Pm>.<T> if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer m = UInt(Pm); constant integer dn = UInt(Rdn); <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> Is the size specifier, size <T> 00 B 01 H 10 S 11 D 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;