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The QR decomposition test program can now called with parameters for
matrix size, nev, and block size.
This closses issue #20

Michael Bankd (debian) provided a patch, which allows
to run the qr-decomposition test programs with smaller matrices, and
thus allows testing in reasonable time on limited hardware (e.g. arm
devices)

In order to make the patch work, also Makefile.am was updated

Some of the file names were too long, automake then dropped these
files when doing "make distcheck"

Now this is done consistently both in autoconf and automake. One can now
safely call make clean and the header files are re-generated
automatically.

Automake does not easily allow to use the same source in a libtool
library and in a program

The issue why these test programs are simply not build
has to be investigated

It turned out that if a CPU supports SSE the already existing
test for SSE assembly instructions always passes.
However, the compilation of gcc SSE intrinic instructions might
nevertheless fail if gcc is not called with one of the options
"-msse3", "-msse4" , "-msse4.1", "-msse4.2", "-mavx", or "-mavx2"!

Obviously gcc does still not consider SSE as a standard on X86_64
Intel CPUs.

An additional configure test has been introduced, which test for
gcc intrinsic sse instructions. If this test fails, the corresponding
kernels are switched off.

The C++ kernels can be written as C kernels, which simplifies the build
procedure

In order to increase type safty all ELPA2 kernels provide now
an interface. The interfaces for the C/C++ kernels are automatically
generated during the configure step

The test programs are just needed at the build step (make check),
they are useless for users and will not be installed anymore

For the Intel compiler, this was assured with the pragma

  !DEC$ ATTRIBUTES ALIGN: 64:: a

however, other compilers such as gcc of course did not honour this,
which could result in SIGSEGVs in case the variable was not aligned to
32 bytes (by chance!).

This fixes issue #11, thanks to Nico Holmberg for reporting this.

The SSE kernels with blocking of 2,4,6 (real case) and 1,2 (complex)
case are now available by default

Thus the following changes have been done
- introduce new macros in configure.ac and Makefile.am
- renmae the AVX kernels in AVX_AVX2 (they also support AVX2)
- introduce new files with SSE kernel
- introduce new kernel parameters !
- make the SSE kernels callable

The results are identical with previous kernels

- The SSE part will be available in different files.
- Specify whether AVX or AVX2 was used to build

The single precision version of the SSE assembly kernel is about 1.8
times faster than the double precision version

library

It the configure option "--enable-single-precision" is specified,
ELPA will also be build for single precision usage. The double precision
and single precision will be available at the same time with names
"solve_evp_real_1stage_double" or "solve_evp_real_1stage_single" and
so on...

This change immplied some major refactoring of the ELPA code:
1.) functions/procedures had to be renamed with suffix "_double"

2.) If necessary the same functions have to be available with suffix
"_single"

3.) Variable kind definitions have to be consistent with the
intented use

To avoid uneccessary code duplication this is done (most of the time)
with preprocessor string substitution.

The documentation has been updated.

NOT SUPPORTED are at the moment:

- single precision usage of ELPA2 with kernels, others than "generic"
  and "generic_simple"

- single precision usage of GPU

The test programs include the same template now, the
printed messages are thus unified

The configure flag "--enable-shared-memory-only" triggers a build
of ELPA without MPI support:

- all MPI calls are skipped (or overloaded)
- all calls to scalapack functions are replaced by the corresponding
  lapack calls
- all calls to blacs are skipped

Using ELPA without MPI gives the same results as using ELPA with 1 MPI
task!

This version is not yet optimized for performance, here and there some
unecessary copies are done.

Ths version is intended for users, who do not have MPI in their
application but still would like to use ELPA on one compute node