Using Intel oneAPI and MKL with CMake

August 26, 2023

There can be substantial speed boosts from Intel compilers with Intel CPUs. Intel oneAPI gives advanced debuggers and performance measurements. Intel oneMKL can give a significant speed boost to ABI-compatible compilers for certain math operations.

For Windows, use the oneAPI Command Prompt. Otherwise, specify environment variables CC, CXX, FC to indicate desired compilers via script:

Build with CMake:

cmake -B build

cmake --build build

Example CMakeLists.txt

To see the compiler commands CMake is issuing, use

cmake --build build -v

Refer to Intel Link Advisor for supported compiler / operating system / MKL combinations.

Get runtime confirmation that MKL is being used via MKL_VERBOSE.

Linux:
```
MKL_VERBOSE=1 ./mytest
```
Windows
```
set MKL_VERBOSE=1
mytest.exe
```

That gives verbose text output upon use of MKL functions. That runtime option does slow down MKL performance, so normally we don’t use it.