Compare the lower single-precision (32-bit) floating-point element in a and b based on the
comparison operand specified by imm8, store the result in the lower element of result, and
copy the upper 3 packed elements from a to the upper elements of result.
Compare the lower single-precision (32-bit) floating-point element in a and b based on the comparison operand specified by imm8, store the result in the lower element of result, and copy the upper 3 packed elements from a to the upper elements of result.