Metal shader converter converts shader intermediate representations in LLVM IR bytecode into bytecode suitable to be loaded into Metal. It's available as a command-line tool (metal-shaderconverter) and a dynamic library (libmetalirconverter). Every feature available in the tool is also available in the library.
Metal shader converter requires macOS 13 Ventura and Xcode 15, or later.
Metal shader converter for Windows requires Microsoft Windows 10 and Microsoft Visual Studio 2019, or later.
Metal libraries built using Metal shader converter tools require a device that supports Argument Buffers Tier 2, running macOS 14 Sonoma, iOS 17 or later. If you build a Metal library for earlier OS versions, not all features will be supported.
The Metal shader converter executable offers several options to customize code generation. In its most basic form, Metal shader converter takes a DXIL file as input and produces a metallib.
% metal-shaderconverter shader.dxil -o shader.metalliblibmetalirconverter)libmetalirconverter offers a C interface for easy integration into C, C++, Objective-C, and Swift codebases.
IRCompiler* compiler = IRCompilerCreate();
IRCompilerSetEntryPointName(compiler, "MainVS");
IRObject* dxil = IRObjectCreateFromDXIL(bytecode, size, IRBytecodeOwnershipNone);
IRError* error = nullptr;
IRObject* outIR = IRCompilerAllocCompileAndLink(compiler, NULL, dxil, &error);
// Retrieve metallib bytes:
IRMetalLibBinary* metallib = IRMetalLibBinaryCreate();
IRObjectGetMetalLibBinary(outIR, stage, metallib);
size_t metallibSize = IRMetalLibGetBytecodeSize(metallib);
uint8_t* metallibBytes = new uint8_t[metallibSize];
IRMetalLibGetBytecode(metallib, metallibBytes);
// Clean up:
delete [] metallibBytes;
IRMetalLibBinaryDestroy(metallib);
IRObjectDestroy(dxil);
IRObjectDestroy(outIR);
IRCompilerDestroy(compiler);| Shader model | Notable features |
|---|---|
| SM6.0 | Wave intrinsics, 64-bit integers |
| SM6.1 | Barycentrics (linear interpolation) |
| SM6.2 | 16-bit scalar types |
| SM6.3 | Ray tracing |
| SM6.4 | Packed dot-product intrinsics |
| SM6.5 | Mesh and Amplification shaders |
| SM6.6 | Dynamic resources, compute derivatives, IsHelperLane |
| Version | Highlights |
|---|---|
| 4.0 | 2D compute derivatives; NaN/Inf optimization on by default |
| 3.1 | libmetalirconverter on iOS |
| 3 | Function constants, framebuffer fetch, Metal intersection function buffers, non-array texture types by default |
| 2 | Shader debug info, globally-coherent memory, ray generation as compute kernels |
| 1.1 | Ray tracing shaders |
| 1 | Initial release |