SPIR-V is a binary intermediate language commonly used for GPU computations and targeted by many projects (including OpenCL, OpenMP and SYCL). In this talk, we will discuss what it took to upstream SPIR-V GlobalISel-based backend, present some of the issues stemming from the high-level design of the language, and explain the steps required to maintain the target in-tree. We will also talk briefly about the extensibility, support for other APIs/SPIR-V flavors (e.g. Vulkan), and the ongoing effort to unify methods of lowering builtins across GPU targets.