ADDP (scalar)

Add pair of elements (scalar)

This instruction adds two vector elements in the source SIMD&FP register and writes the scalar result into the destination SIMD&FP register.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

Advanced SIMD
(FEAT_AdvSIMD)

313029282726252423222120191817161514131211109876543210
0101111011110001101110RnRd
Usizeopcode

Encoding

ADDP D<d>, <Vn>.2D

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); end; let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let esize : integer{} = 64; let datasize : integer{} = 128;

Assembler Symbols

<d>

Is the number of the SIMD&FP destination register, encoded in the "Rd" field.

<Vn>

Is the name of the SIMD&FP source register, encoded in the "Rn" field.

Operation

AArch64_CheckFPAdvSIMDEnabled(); let operand : bits(datasize) = V{}(n); V{esize}(d) = IntReduce{esize, datasize}(ReduceOp_ADD, operand);

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.


2026-03_rel 2026-03-26 20:48:11

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