Remove OpenMP search when not using likwid

[tpadioleau]

This PR removes the search of OpenMP when not using likwid. This mimics the search happening in the build stage,

GMGPolar/CMakeLists.txt

Lines 57 to 60 in 9356b29

	if(GMGPOLAR_USE_LIKWID)
	find_package(OpenMP REQUIRED COMPONENTS CXX)
	find_package(LIKWID REQUIRED)
	endif()

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[tpadioleau]

@mknaranja do you mind reviewing ? :)

[mknaranja]

are you not using OpenMP anymore ?

And have you mixed up LIKWID/MUMPS above ?

Just to be sure that's everything is as intended ;)

[tpadioleau]

are you not using OpenMP anymore ?

I just aligned the build and install cmake files. Note that grepping omp in source files is now empty. But in the end I prefer to let @EmilyBourne or @AbdelhadiKara confirm that OpenMP is gone.

And have you mixed up LIKWID/MUMPS above ?

Where exactly ?

Just to be sure that's everything is as intended ;)

Sure you are very right

[mknaranja]

"This PR removes the search of OpenMP when not using likwid" --> you meant MUMPS, right?

[julianlitz]

If Likwid=Off and Mumps=Off, OpenMP is not used anymore.

Likwid=On: The Likwid markers are initialized inside a parallel region -> OpenMP is used here.

AI: "When MUMPS=ON, we don't need find_package(OpenMP) in our CMake, since our code never calls OpenMP directly. MUMPS can be built with or without OpenMP (see GMGPolar README.md file) if built with it, the dependency is already baked into MUMPS's own library/link config, so it comes along transitively when we link against MUMPS."

Thus I would move the +1 code addition to the if(Likwid) section.

(For the Mumps section I would guess that
find_dependency(MUMPS) is enough and "components OpemMP Metis" isnt needed.)

[julianlitz]

[tpadioleau]

Yes of course you are correct let me fix this.

[tpadioleau]

Fixed in 8fcc596.

That said, do we still have any OpenMP calls in the repo ? I don't see omp.h nor any pragma omp.

[julianlitz]

The only ones are: At the bottom of include/Definitions/global_definitions.h.

We are probably missing an omp.h include in that file. I never tested if Likwid still works.