FMAXNMV

Floating-point maximum number recursive reduction to scalar

Floating-point maximum number horizontally over all lanes of a vector using a recursive pairwise reduction, and place the result in the SIMD&FP scalar destination register. Inactive elements in the source vector are treated as the default NaN.

Regardless of the value of FPCR.AH, the behavior is as follows:

  • Negative zero compares less than positive zero.
  • If one value is numeric and the other is a quiet NaN, the result is the numeric value.
  • When FPCR.DN is 0, if either value is a signaling NaN or if both values are NaNs, the result is a quiet NaN.
  • When FPCR.DN is 1, if either value is a signaling NaN or if both values are NaNs, the result is Default NaN.

    • Encoding: SVE

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

    313029282726252423222120191817161514131211109876543210
    01100101000100001
    sizeopcPgZnVd

    FMAXNMV <V><d>, <Pg>, <Zn>.<T>

    Decoding algorithm

    if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
    EndOfDecode(Decode_UNDEF);
if size == '00' then EndOfDecode(Decode_UNDEF);
constant integer esize = 8 << UInt(size);
constant integer g = UInt(Pg);
constant integer n = UInt(Zn);
constant integer d = UInt(Vd);

    Operation

    CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant bits(PL) mask = P[g, PL];
constant bits(VL) operand = if AnyActiveElement(mask, esize) then Z[n, VL] else Zeros(VL);
constant bits(esize) identity = FPDefaultNaN(FPCR, esize);

V[d, esize] = FPReducePredicated(ReduceOp_FMAXNUM, operand, mask, identity, FPCR);

    Explanations

    <V>: <d>: Is the number [0-31] of the destination SIMD&FP register, encoded in the "Vd" field.
    <Pg>: Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.
    <Zn>: Is the name of the source scalable vector register, encoded in the "Zn" field.
    <T>: