vaba

Vector Absolute Difference and Accumulate

VABA<c>.<dt> <Qd>, <Qn>, <Qm>

Computes absolute difference and adds to accumulator.

Pseudocode Operation

for i = 0 to num_elements(Qd, dt) - 1
  diff ← abs(Qn[i] - Qm[i])
  Qd[i] ← Qd[i] + diff

Example

VABA.dt q0, q1, q2

Encoding

Binary Layout

1111001

31:25

U

24

0

23

D

22

size

21:20

Vn

19:16

Vd

15:12

0111

11:8

N

7

0

6

M

5

1

4

Vm

3:0

 

Format NEON 3-Reg

Opcode 0xF2000710

Extension NEON (SIMD)

Operands

• Qd
  Dest/Acc
• Qn
  First source 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
0xF2000710	VABA{<c>}{<q>}.<dt> <Dd>, <Dn>, <Dm>		A32		1111001 | U | 0 | D | size | Vn | Vd | 0111 | N | 0 | M | 1 | Vm
0xF2000750	VABA{<c>}{<q>}.<dt> <Qd>, <Qn>, <Qm>		A32		1111001 | U | 0 | D | size | Vn | Vd | 0111 | N | 1 | M | 1 | Vm
0xEF000710	VABA{<c>}{<q>}.<dt> <Dd>, <Dn>, <Dm>		T32		111 | U | 11110 | D | size | Vn | Vd | 0111 | N | 0 | M | 1 | Vm
0xEF000750	VABA{<c>}{<q>}.<dt> <Qd>, <Qn>, <Qm>		T32		111 | U | 11110 | D | size | Vn | Vd | 0111 | N | 1 | M | 1 | Vm

Description

Vector Absolute Difference and Accumulate subtracts the elements of one vector from the corresponding elements of another vector, and accumulates the absolute values of the results into the elements of the destination vector. Operand and result elements are all integers of the same length. 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();
    for r = 0 to regs-1
        for e = 0 to elements-1
            op1 = Elem[Din[n+r],e,esize];
            op2 = Elem[Din[m+r],e,esize];
            absdiff = Abs(Int(op1,unsigned) - Int(op2,unsigned));
            if long_destination then
                Elem[Q[d>>1],e,2*esize] = Elem[Qin[d>>1],e,2*esize] + absdiff;
            else
                Elem[D[d+r],e,esize] = Elem[Din[d+r],e,esize] + absdiff;