SQDMULH (vector)

Signed saturating Doubling Multiply returning High half. This instruction multiplies the values of corresponding elements of the two source SIMD&FP registers, doubles the results, places the most significant half of the final results into a vector, and writes the vector to the destination SIMD&FP register.

The results are truncated. For rounded results, see SQRDMULH.

If overflow occurs with any of the results, those results are saturated. If saturation occurs, the cumulative saturation bit FPSR.QC is set.

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.

It has encodings from 2 classes: Scalar and Vector

Scalar

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size == '11' || size == '00' then UNDEFINED; integer esize = 8 << UInt(size); integer datasize = esize; integer elements = 1; boolean rounding = (U == '1');

Vector

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size == '11' || size == '00' then UNDEFINED; integer esize = 8 << UInt(size); integer datasize = if Q == '1' then 128 else 64; integer elements = datasize DIV esize; boolean rounding = (U == '1');