The name of the CPU CMake is running on.

Windows Platforms

On Windows, this variable is set to the value of the environment variable PROCESSOR_ARCHITECTURE.

Unix Platforms

On systems that support uname, this variable is set to the output of:

  • uname -m on GNU, Linux, Cygwin, Android, or

  • arch on OpenBSD, or

  • on other systems,

    • uname -p if its exit code is nonzero, or

    • uname -m otherwise.

macOS Platforms

The value of uname -m is used by default.

On Apple Silicon hosts, the architecture printed by uname -m may vary based on CMake's own architecture and that of the invoking process tree.

New in version 3.19.2: On Apple Silicon hosts: