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SIMD ISAReturn TypeNameArgumentsInstruction Group
Neonint64_tvqdmlsls_laneq_s32(int64_t a, int32_t b, int32x4_t v, const int lane)Vector arithmetic / Multiply / Saturating multiply-accumulate
Description
Signed saturating Doubling Multiply-Subtract Long (by element). This instruction multiplies each vector element in the lower or upper half of the first source SIMD&FP register by the specified vector element of the second source SIMD&FP register, doubles the results, and subtracts the final results from the vector elements of the destination SIMD&FP register. The destination vector elements are twice as long as the elements that are multiplied. All the values in this instruction are signed integer values.
Results
Dd result
This intrinsic compiles to the following instructions:

SQDMLSL Dd,Sn,Vm.S[lane]

Argument Preparation
a register: Ddb register: Snv register: Vm.4Slane minimum: 0; maximum: 3
Architectures
A64

Operation

CheckFPAdvSIMDEnabled64();
bits(datasize)   operand1 = Vpart[n, part];
bits(datasize)   operand2 = Vpart[m, part];
bits(2*datasize) operand3 = V[d];
bits(2*datasize) result;
integer element1;
integer element2;
bits(2*esize) product;
integer accum;
boolean sat1;
boolean sat2;

for e = 0 to elements-1
    element1 = SInt(Elem[operand1, e, esize]);
    element2 = SInt(Elem[operand2, e, esize]);
    (product, sat1) = SignedSatQ(2 * element1 * element2, 2*esize);
    if sub_op then
        accum = SInt(Elem[operand3, e, 2*esize]) - SInt(product);
    else
        accum = SInt(Elem[operand3, e, 2*esize]) + SInt(product);
    (Elem[result, e, 2*esize], sat2) = SignedSatQ(accum, 2*esize);
    if sat1 || sat2 then FPSR.QC = '1';

V[d] = result;