Vulkan® API Layer (XGL)

The Vulkan API Layer (XGL) translates Vulkan API commands into PAL commands. It compiles shaders that compose a particular VkPipeline object as a single entity using the LLVM-Based Pipeline Compiler (LLPC) library.

LLPC builds on LLVM's existing shader compilation infrastructure for AMD GPUs to generate code objects compatible with PAL's pipeline ABI. It consists of three components:

• SPIR-V translator is based on Khronos SPIRV-LLVM translator. It translates SPIR-V binary to LLVM IR with rich metadata.

• Lower translates all LLVM compiler unsupported LLVM IR and metadata to function calls.

Both SPIR-V translator and Lower are machine independent.

• Patcher replaces all external function calls with LLVM compiler compatible LLVM IR according to the pipeline information. It calls LLVM and reorganizes LLVM compiler's output with PAL Pipeline ABI.

Third Party Software

XGL contains code written by third parties:

• SPIRV-LLVM translator is distributed under the terms of University of Illinois/NCSA Open Source License. See icd/api/llpc/translator/LICENSE.TXT.
• LLVM opt is distributed under the terms of University of Illinois/NCSA Open Source License. See icd/api/llpc/imported/llvm/opt/LICENSE.TXT.
• SPIRV-Tools is distributed under the terms of Apache License version 2.0. See icd/api/llpc/translator/hex_float.h and bitutils.h.
• Metrohash is distributed under the terms of MIT License. See icd/api/llpc/imported/metrohash/metrohash-license.