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.

SVE2
(FEAT_SVE2 || FEAT_SME)

313029282726252423222120191817161514131211109876543210
01100100size010000100PgZmZdn
opc

Encoding

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

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE2) && !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 m = UInt(Zm); constant 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(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; constant bits(PL) mask = P[g, PL]; constant bits(VL) operand1 = Z[dn, VL]; constant bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m, VL] else Zeros(VL); bits(VL) result = Z[dn, VL]; bits(esize) element1; bits(esize) element2; for e = 0 to elements-1 if ActivePredicateElement(mask, e, esize) 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, VL] = result;

Operational information

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


Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18

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