vpadal

Vector Pairwise Add and Accumulate Long

VPADAL<c>.<dt> <Qd>, <Qm>

Adds adjacent pairs and accumulates into wide destination.

Pseudocode Operation

for i = 0 to (pairs_in_Qm - 1)
  Qd[i] ← Qd[i] + (Qm[2*i] + Qm[2*i+1])

Example

VPADAL.dt q0, q2

Encoding

Binary Layout
111100111
31:23
D
22
11
21:20
size
19:18
00
17:16
Vd
15:12
0
11
110
10:8
op
7
0
6
M
5
0
4
Vm
3:0
 
Format NEON 2-Reg
Opcode 0xF3B00600
Extension NEON (SIMD)

Operands

  • Qd
    Destination 128-bit SIMD register
  • Qm
    Second source 128-bit SIMD register

Related

More in NEON (SIMD)

Reference

View in Arm A64 ISA Reference ↗ Arm AArch32 ISA

Instruction Forms

Encoding Instruction ISA Bit pattern
0xF3B00600 VPADAL{<c>}{<q>}.<dt> <Dd>, <Dm> A32 111100111 | D | 11 | size | 00 | Vd | 0 | 110 | op | 0 | M | 0 | Vm
0xF3B00640 VPADAL{<c>}{<q>}.<dt> <Qd>, <Qm> A32 111100111 | D | 11 | size | 00 | Vd | 0 | 110 | op | 1 | M | 0 | Vm
0xFFB00600 VPADAL{<c>}{<q>}.<dt> <Dd>, <Dm> T32 111111111 | D | 11 | size | 00 | Vd | 0 | 110 | op | 0 | M | 0 | Vm
0xFFB00640 VPADAL{<c>}{<q>}.<dt> <Qd>, <Qm> T32 111111111 | D | 11 | size | 00 | Vd | 0 | 110 | op | 1 | M | 0 | Vm

Description

Vector Pairwise Add and Accumulate Long adds adjacent pairs of elements of a vector, and accumulates the results into the elements of the destination vector. The vectors can be doubleword or quadword. The operand elements can be 8-bit, 16-bit, or 32-bit integers. The result elements are twice the length of the operand elements. Depending on settings in the CPACR, NSACR, and HCPTR registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be undefined, or trapped to Hyp mode. For more information see Enabling Advanced SIMD and floating-point support.

Operation

if ConditionPassed() then
    EncodingSpecificOperations();  CheckAdvSIMDEnabled();
    h = elements DIV 2;

    for r = 0 to regs-1
        for e = 0 to h-1
            op1 = Elem[D[m+r],2*e,esize];  op2 = Elem[D[m+r],2*e+1,esize];
            result = Int(op1, unsigned) + Int(op2, unsigned);
            Elem[D[d+r],e,2*esize] = Elem[D[d+r],e,2*esize] + result;