FADDP

Floating-point add pairwise

Add pairs of adjacent floating-point elements within each source vector, and interleave the results from corresponding lanes. The interleaved result values are destructively placed in the first source vector.

313029282726252423222120191817161514131211109876543210
01100100size010000100PgZmZdn

FADDP <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T>

if !HaveSVE2() && !HaveSME() then UNDEFINED; if size == '00' then UNDEFINED; integer esize = 8 << UInt(size); integer g = UInt(Pg); integer m = UInt(Zm); integer dn = UInt(Zdn);

Assembler Symbols

<Zdn>

Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.

<T>

Is the size specifier, encoded in size:

size <T>
00 RESERVED
01 H
10 S
11 D
<Pg>

Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.

<Zm>

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

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(VL) operand1 = Z[dn]; bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m] else Zeros(); bits(VL) result = Z[dn]; bits(esize) element1; bits(esize) element2; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' then if IsEven(e) then element1 = Elem[operand1, e + 0, esize]; element2 = Elem[operand1, e + 1, esize]; else element1 = Elem[operand2, e - 1, esize]; element2 = Elem[operand2, e + 0, esize]; Elem[result, e, esize] = FPAdd(element1, element2, FPCR[]); Z[dn] = result;

Operational information

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX instruction must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is unpredictable:


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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