[CMake] Finding Blas

[Brad King]

Shepherd, Jason F wrote:
> A follow on question:  What if I don't want to require clapack,
> but want to allow it if available.  What is the correct way to
> check for clapack or lapack?

The find_package() command has a QUIET option that could be used
to look for one and then the other without complaining if one
is missing.

> Would it be possible to make the find_package(clapack) a part
> of the normal cmake routines for find_package(lapack)?

This looks like a good idea.  I haven't investigated this fully
but it may be as simple as adding something like

  find_package(CLAPACK QUIET NO_MODULE)
  if(CLAPACK_FOUND)
    # Convert CLAPACK_* results and store in LAPACK variables
    set(LAPACK_LIBRARIES lapack blas)
    ...
  endif()

to FindLAPACK.cmake (plus some more code to interact with FindBLAS).

Alin, you are currently listed as the maintainer:

  http://www.cmake.org/Wiki/CMake:Module_Maintainers

Would you be willing/able to take a look at this idea, or guide
someone else who volunteers?

Thanks,
-Brad