The LLVM/SPIR-V Bi-Directional Translator is a library and tool for translation
between LLVM IR and SPIR-V.

SPIR-V is a binary intermediate language for representing graphical-shader
stages and compute kernels for multiple Khronos APIs, including OpenCL,
OpenGL, and Vulkan. SPIR-V defines a new language and is a successor to the
original Khronos SPIR, which supported only OpenCL device programs.