FMAXNM (multiple and single vector)

Multi-vector floating-point maximum number by vector

Determine the maximum number value of floating-point elements of the second source vector and the corresponding floating-point elements of the two or four first source vectors and destructively place the results in the corresponding elements of the two or four first source vectors.

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

This instruction follows SME2 floating-point numerical behaviors corresponding to instructions that place their results in one or more SVE Z vectors.

This instruction is unpredicated.

It has encodings from 2 classes: Two registers and Four registers

Two registers
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001!= 0010Zm10100001001Zdn0
size

FMAXNM { <Zdn1>.<T>-<Zdn2>.<T> }, { <Zdn1>.<T>-<Zdn2>.<T> }, <Zm>.<T>

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer dn = UInt(Zdn:'0'); constant integer m = UInt('0':Zm); constant integer nreg = 2;

Four registers
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001!= 0010Zm10101001001Zdn00
size

FMAXNM { <Zdn1>.<T>-<Zdn4>.<T> }, { <Zdn1>.<T>-<Zdn4>.<T> }, <Zm>.<T>

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer dn = UInt(Zdn:'00'); constant integer m = UInt('0':Zm); constant integer nreg = 4;

Assembler Symbols

<Zdn1>

For the two registers variant: is the name of the first scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 2.

For the four registers variant: is the name of the first scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 4.

<T>

Is the size specifier, encoded in size:

size <T>
01 H
10 S
11 D
<Zdn4>

Is the name of the fourth scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 4 plus 3.

<Zdn2>

Is the name of the second scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 2 plus 1.

<Zm>

Is the name of the second source scalable vector register Z0-Z15, encoded in the "Zm" field.

Operation

CheckStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; array [0..3] of bits(VL) results; for r = 0 to nreg-1 constant bits(VL) operand1 = Z[dn+r, VL]; constant bits(VL) operand2 = Z[m, VL]; for e = 0 to elements-1 constant bits(esize) element1 = Elem[operand1, e, esize]; constant bits(esize) element2 = Elem[operand2, e, esize]; Elem[results[r], e, esize] = FPMaxNum(element1, element2, FPCR); for r = 0 to nreg-1 Z[dn+r, VL] = results[r];


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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