DirectXShaderCompiler

The Microsoft HLSL compiler for dx12+ is based on LLVM and supports spir-v output https://github.com/microsoft/DirectXShaderCompiler Though my understanding is that it's a complete hackjob stuck on an old version of LLVM, and not in a remotely upstream-able state and breaks other parts of the LLVM toolchain completely. I think there was talk about trying to clean that up at the same time as bringing the baseline version forward, but I have no idea about it's progress.

On the latest release https://github.com/microsoft/DirectXShaderCompiler/releases/... There are "source code" files in zip and tar.gz Aren't those source code for those dlls?

Which part of dxil/dxc is proprietary exactly? Trying to make sense of the license barf at https://github.com/microsoft/DirectXShaderCompiler

No, it's C++, based on LLVM. https://github.com/microsoft/DirectXShaderCompiler Edit: apparently dxil.dll is not part of DXC (the classic move to make "open source" software dependent on external proprietary garbage, apparently.) But I'd still doubt it's a managed DLL.

> DXC’s fork of LLVM removed and/or damaged much of the code generation layer and infrastructure [of LLVM]. Given that, supporting DXBC generation in DXC would be a massive task to fix and restore broken LLVM functionality. Due to the large scale of this issue and resource constraints on our team we’re not going to address this issue in [the new] DXC [compiler] ever. > > We may support DXBC generation in Clang in the future (we mentioned that in the original proposal to LLVM). That work is unlikely to begin for a few years as our focus will be on supporting DXIL and SPIR-V generation first. I appreciate this quote[0] from the microsoft camp. Setting clear expectations that something will not be done is a nice bit of fresh air. [0] https://github.com/microsoft/DirectXShaderCompiler/issues/57...

Well... they are rewriting & upstreaming DXC to LLVM main (https://github.com/microsoft/DirectXShaderCompiler/wiki/Cont...) and want to kinda deprecate DXC. IIRC currently only compute shaders are supported but I may be very wrong.

There's no need for transpilers these days, you can just compile HLSL to SPIR-V bytecode with dxc. https://github.com/microsoft/DirectXShaderCompiler

Also Microsoft DirectX Shader Compiler[1] for HLSL. In fact, effort is ongoing to upstream HLSL support into Clang.[2][3][4] To answer your other question—why LLVM instead of GCC: - First-class support for non-Unix/Linux platforms. LLVM can be built on Windows and Visual Studio without ever needing a single GNU tool besides git[5]. Clang even has a MSVC-compatible interface that allows MSVC developers to switch to Clang without needing to change their command-line invocation[6]. - Written in C++ from the ground up, with a modular, first-class SSA IR-based interface. - Permissive Apache 2.0 licence. As much as this might exasperate the open-source community, it allows for significantly faster iteration; things tend to be upstreamed when private/corporate developers realise it is hard to maintain separate forks. All this allows LLVM to have