| 摘要 |
Disclosed is an apparatus 8 to selectively perform multi-element comparison and addition on packed data items such as vectors. The apparatus has non-final reduction stages, each with a non-final intermediate operand forming stage 10 to form intermediate operands from an input vector and intermediate sum values output from a preceding non-final reduction stage. The non-final stages also have carry propagate adders stages 12 to add respective pairs of the intermediate operands to form intermediate sum values. A final reduction stage has a final intermediate operand stage 16 that forms final intermediate operands from intermediate sum values output from the non-final reduction stages. The final stage also has an output adder stage 18 to generate an output by adding the final intermediate operands. The reduction stages may also have a non-final limit value selecting stage 14 active when performing a multi-element comparison, to select in dependence upon the carry values generated by the carry propagate adders stage, limit values that are the larger or smaller value of a pair of elements. |
