I think they belong to the same generation. The overall level is similar.
Kirin 980 is a Huawei designed 4*A76 4*A55 eight-core chip, using TSMC 7nm process manufacturing, the highest frequency up to 2.6GHz. The Snapdragon 855 is a mobile processing platform produced by Qualcomm, which uses TSMC's 7nm process and uses eight-core Kryo CPU. 485 architecture, compared with the Snapdragon 845 CPU performance improvement of about 45%, GPU using Adreno? 640, compared with the previous generation of products graphics rendering capacity increased by about 20%. Overall, they're pretty much the same.