I would like to know the difference between
Is LAPACKE_cgesvd just a wrapper around cgesvd automatically selecting the resources? Is there any performance improvement/penalty using the former or the latter?
Thank you very much for any help.
Yes, the LAPACKE_cgesvd just a wrapper around cgesvd automatically selecting the resources for convenience of C developers. It may lower the performance but considering the problem size, the performance penalty can be ignored in most cases.
Here is one thread to discuss the design background of C interface to LAPACKL
Disadvantages to using a wrapper approach to access existing FORTRAN subprograms are
increased memory footprints and lower performance where a transpose is needed. Another way
to implement row-major C interfaces without an increase in memory is to re-organize the
LAPACK algorithms (for instance, LU factorization to be mapped on row-major ordering) or use
tricks to call some complementary routine such as dgelqf for dgeqrf, .