Cpu.Apple.Inc - Vllm

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vLLM has experimental support for macOS with Apple Silicon. For now, users must build from source to natively run on macOS.

Currently the CPU implementation for macOS supports FP32 and FP16 datatypes.

!!! tip "GPU-Accelerated Inference with vLLM-Metal" For GPU-accelerated inference on Apple Silicon using Metal, check out vllm-metal, a community-maintained hardware plugin that uses MLX as the compute backend.

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OS: macOS Sonoma or later
SDK: XCode 15.4 or later with Command Line Tools
Compiler: Apple Clang >= 15.0.0

!!! note The macOS CPU build is smoke-tested in CI on the latest GA Apple Silicon runner; other macOS or Apple Clang versions are best-effort.

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Currently, there are no pre-built Apple silicon CPU wheels.

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After installation of XCode and the Command Line Tools, which include Apple Clang, execute the following commands to build and install vLLM from source.

bash

git clone https://github.com/vllm-project/vllm.git
cd vllm
uv pip install -r requirements/cpu.txt
uv pip install -e .

!!! note On macOS the VLLM_TARGET_DEVICE is automatically set to cpu, which is currently the only supported device.

!!! example "Troubleshooting" If the build fails with errors like the following where standard C++ headers cannot be found, try to remove and reinstall your Command Line Tools for Xcode.

```text
[...] fatal error: 'map' file not found
        1 | #include <map>
            |          ^~~~~
    1 error generated.
    [2/8] Building CXX object CMakeFiles/_C.dir/csrc/cpu/pos_encoding.cpp.o

[...] fatal error: 'cstddef' file not found
        10 | #include <cstddef>
            |          ^~~~~~~~~
    1 error generated.
```

---

If the build fails with C++11/C++17 compatibility errors like the following, the issue is that the build system is defaulting to an older C++ standard:

```text
[...] error: 'constexpr' is not a type
[...] error: expected ';' before 'constexpr'
[...] error: 'constexpr' does not name a type
```

**Solution**: Your compiler might be using an older C++ standard. Edit `cmake/cpu_extension.cmake` and add `set(CMAKE_CXX_STANDARD 17)` before `set(CMAKE_CXX_STANDARD_REQUIRED ON)`.

To check your compiler's C++ standard support:
```bash
clang++ -std=c++17 -pedantic -dM -E -x c++ /dev/null | grep __cplusplus
```
On Apple Clang 16 you should see: `#define __cplusplus 201703L`

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Currently, there are no pre-built Arm silicon CPU images.

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