Microsoft DirectX 12 Shifts to SPIR-V as Default Interchange Format
Microsoft's Direct3D and HLSL teams have unveiled plans to integrate SPIR-V support into DirectX 12 with the upcoming release of Shader Model 7. This significant transition marks a new era in GPU programmability, as it aims to unify the intermediate representation for graphical-shader stages and compute kernels. SPIR-V, an open standard intermediate representation for graphics and compute shaders, will replace the proprietary DirectX Intermediate Language (DXIL) as the shader interchange format for DirectX 12. The adoption of SPIR-V is expected to ease development processes across multiple GPU runtime environments. By embracing this open standard, Microsoft aims to enhance HLSL's position as the premier language for compiling graphics and compute shaders across various devices and APIs. This transition is part of a multi-year development process, during which Microsoft will work closely with The Khronos Group and the LLVM Project. The company has joined Khronos' SPIR and Vulkan working groups to ensure smooth collaboration and rapid feature adoption.
While the transition will take several years, Microsoft is providing early notice to allow developers and partners to plan accordingly. The company will offer translation tools between SPIR-V and DXIL to facilitate a gradual transition for both application and driver developers. For those not familiar with graphics development, graphics APIs ship with virtual instruction set architectures (ISA) that abstracts standard hardware features at a higher level. As GPUs don't follow the same ISA as CPUs (x86, Arm, RISC-V), this virtual ISA is needed to define some generics in the GPU architecture and allow various APIs like DirectX and Vulkan to run. Instead of focusing support on several formats like DXIL, Microsoft is embracing the open SPIR-V standard, which will become de facto for API developers in the future, allowing focus on more features instead of constantly replicating each other's functions. While DXIL is used mainly for gaming environments, SPIR-V has adoption in high-performance computing as well, with OpenCL and SYCL. Gaming presence is also there with Vulkan API, and we expect to see SPIR-V join DirectX 12 games.
While the transition will take several years, Microsoft is providing early notice to allow developers and partners to plan accordingly. The company will offer translation tools between SPIR-V and DXIL to facilitate a gradual transition for both application and driver developers. For those not familiar with graphics development, graphics APIs ship with virtual instruction set architectures (ISA) that abstracts standard hardware features at a higher level. As GPUs don't follow the same ISA as CPUs (x86, Arm, RISC-V), this virtual ISA is needed to define some generics in the GPU architecture and allow various APIs like DirectX and Vulkan to run. Instead of focusing support on several formats like DXIL, Microsoft is embracing the open SPIR-V standard, which will become de facto for API developers in the future, allowing focus on more features instead of constantly replicating each other's functions. While DXIL is used mainly for gaming environments, SPIR-V has adoption in high-performance computing as well, with OpenCL and SYCL. Gaming presence is also there with Vulkan API, and we expect to see SPIR-V join DirectX 12 games.
