WHILEHS (predicate pair)

While decrementing unsigned scalar higher than or same as scalar (pair of predicates)

This instruction generates a pair of predicates that starting from the highest numbered element of the pair is true while the decrementing value of the first, unsigned scalar operand is higher than or the same as the second scalar operand and false thereafter down to the lowest numbered element of the pair.

If the second scalar operand is equal to the minimum unsigned integer value, then a condition that includes an equality test can never fail and the result will be an all-true predicate.

The full width of the scalar operands is significant for the purposes of comparison, and the full width first operand is decremented by one for each destination predicate element, irrespective of the predicate result element size. The first general-purpose source register is not itself updated.

The lower-numbered elements are placed in the first predicate destination register, and the higher-numbered elements in the second predicate destination register. This instruction sets the First (N), None (Z), and !Last (C) condition flags based on the predicate result, and sets the V flag to zero.

SVE2
(FEAT_SME2 || FEAT_SVE2p1)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let rsize : integer{} = 64; let n : integer = UInt(Rn); let m : integer = UInt(Rm); let d0 : integer = UInt(Pd::'0'); let d1 : integer = UInt(Pd::'1'); let unsigned : boolean = TRUE; let op : CmpOp = Cmp_GE;