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SIMD ISAReturn TypeNameArgumentsInstruction Group
Neonint64x2_tvqdmlsl_s32(int64x2_t a, int32x2_t b, int32x2_t c)Vector arithmetic / Multiply / Saturating multiply-accumulate
Description
Signed saturating Doubling Multiply-Subtract Long. This instruction multiplies corresponding signed integer values in the lower or upper half of the vectors of the two source SIMD&FP registers, 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.
Results
Vd.2D result
This intrinsic compiles to the following instructions:

SQDMLSL Vd.2D,Vn.2S,Vm.2S

Argument Preparation
a register: Vd.2Db register: Vn.2Sc register: Vm.2S
Architectures
v7, A32, 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;