It seems like the VERSION_GREATER_EQUAL operator for boolean
expressions was introduced after CMake 3.6 and hence the current
check whether to activate CUDA or not is broken in version 3.6 and
below.
This PR fixes this by using VERSION_GREATER.
Closes#2375.
We experienced weired linker errors when using host compiler version for
compilation that were not supported by the nvcc used to compile the
cuda code:
```
[ 15%] Linking CXX executable bin/test_timer
/usr/bin/ld: /home/mblatt/src/dune/opm-2.6/opm-common/opm-seq/lib/libopmcommon.a(Parser.cpp.o): in function `Opm::(anonymous namespace)::file& std::vector<Opm::(anonymous namespace)::file, std::allocator<Opm::(anonymous namespace)::file> >::emplace_back<std::filesystem::__cxx11::path&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&>(std::filesystem::__cxx11::path&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)':
Parser.cpp:(.text+0x1096): undefined reference to `std::filesystem::__cxx11::path::_M_split_cmpts()'
/usr/bin/ld: Parser.cpp:(.text+0x10ad): undefined reference to `std::filesystem::__cxx11::path::_M_split_cmpts()'
/usr/bin/ld: /home/mblatt/src/dune/opm-2.6/opm-common/opm-seq/lib/libopmcommon.a(Parser.cpp.o): in function `Opm::(anonymous namespace)::ParserState::loadFile(std::filesystem::__cxx11::path const&)':
Parser.cpp:(.text+0x23a1): undefined reference to `std::filesystem::canonical(std::filesystem::__cxx11::path const&)'
/usr/bin/ld: Parser.cpp:(.text+0x24e0): undefined reference to
`std::filesystem::__cxx11::path::_M_split_cmpts()'
```
The reason turned out to be that the library path was build up by
paths of the old (g++-7) compiler used by nvcc and the actual (newer) compiler
g++-8. This completely messed up the linker paths for CMake.
To detect this situation already when running cmake we have resorted
to first setting the CMAKE_CUDA_FLAGS to force cmake to make nvcc use
the host compiler and to activate CUDA (if available) before calling
`find_package(CUDA)`. If the host compiler is not supported CMake will
error out during `enable(CUDA)`
Note that we still use (deprecated) FindCUDA later to determine the
libraries to link to.
The users has the option to either deactivate CUDA by setting
`-DCMAKE_DISABLE_FIND_PACKAGE_CUDA=ON` or to use a compiler supported
by nvcc (setting `-DCMAKE_CXX_COMPILER=compiler`).
Additionally we do not try to activate CUDA the CMake version is <
3.8. Please note that previously CMake would have errored out here
anyway since we used the unsupported `enable_language(CUDA)` even in
this case.
Closes#2363.
`mebos` works similarly as `flow`, but in contrast to `flow`, `mebos`
only creates the deck in the common code path whilst the
'EclipseState' and the other higher-level parser objects are always
created internally by the vanguard. this approach avoids code
duplication and the worst effects of parser API creep.
to avoid having to compile non-trivial compile units multiple times,
the actual code of the variants is moved into `ebos_$VARIANT.{hh,cc}`
files and the respective compile units are each put into a small
static library whilst the main function of said libraries are invoked
by either the multiplexed or the respective specialized simulator's
`main()`. This is also somewhat similar of how `flow` works, with the
difference that `mebos` uses the blackoil variant to determine the
parameters it needs to know for parsing the deck instead of
introducing a "fake" type tag for this. The rationale is to reduce
compile time compared to the "fake type tag" approach and -- to a
lesser extend -- avoid unnecessary copy-and-pasting of code. In
particular, this means that for the vast majority of cases, only one
place needs changed in the code for all `ebos` variants if, for
example, the parser API requires further objects in the future.
for some reason, this yields quite different results for norne than
the default variant, e.g. when comparing PRESSURE, we get
```
> compareECL -k PRESSURE -t UNRST ebos/NORNE_ATW2013 ebos_altidx/NORNE_ATW2013 1 1e-4
Comparing 'ebos/NORNE_ATW2013' to 'ebos_altidx/NORNE_ATW2013'.
Comparing PRESSURE...
Occurrence in first file = 9
Occurrence in second file = 9
Value index = 0
(first value, second value) = (254.195, 253.191)
Program threw an exception: [/home/and/src/opm-common/build-cmake/fake-src/examples/test_util/EclRegressionTest.cpp:161] Deviations exceed tolerances.
The absolute deviation is 1.00311, and the tolerance limit is 1.
The relative deviation is 0.00394624, and the tolerance limit is 0.0001.
```
IMO this is a bug, but the reasons for it are currently unknown.
this simply excludes the disabled simulators from `make all` while
`make flow` will continue to work even if the cmake variable
`BUILD_FLOW` was set to `OFF`. This requires a small patch for
opm-common.
these variants should cover most of the common use cases. That said,
there are no plans to provide simulators for combinations of blackoil
extensions or a "multiplexing" simulator like `flow`: If someone is
interested in e.g., an oil-water simulator with polymer and energy
enabled, a separate self-compiled executable should be added locally.
for some reason, libraries produced for a module are not linked to the
executables of the module by the default build system. so far this did
not matter for `ebos` but with this PR, it starts using stuff from
`libopmsimulators`...
so far, the actual specializations of the simulator were compiled into
the `libopmsimulators` library and the build of the glue code
(`flow.cpp`) thus needed to be deferred until the library was fully
built. Since the compilation of the glue code requires a full property
hierarchy for handling command line parameters, this arrangement
significantly increases the build time for systems with a sufficient
number of parallel build processes. ("sufficient" here means 8 or more
threads, i.e., a quadcore system with hyperthreading is sufficient
provided that it has enough main memory.)
the new approach is not to include these objects in
`libopmsimulators`, but to directly deal with them in the `flow`
binary. this allows all of them and the glue code to be compiled in
parallel.
compilation time on my machine before this change:
```
> touch ../opm/autodiff/BlackoilModelEbos.hpp; time make -j32 flow 2> /dev/null
Scanning dependencies of target opmsimulators
[ 2%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_gasoil.cpp.o
[ 2%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_oilwater.cpp.o
[ 2%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_blackoil.cpp.o
[ 2%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_solvent.cpp.o
[ 4%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_polymer.cpp.o
[ 6%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_energy.cpp.o
[ 6%] Building CXX object CMakeFiles/opmsimulators.dir/opm/simulators/flow_ebos_oilwater_polymer.cpp.o
[ 6%] Linking CXX static library lib/libopmsimulators.a
[ 97%] Built target opmsimulators
Scanning dependencies of target flow
[100%] Building CXX object CMakeFiles/flow.dir/examples/flow.cpp.o
[100%] Linking CXX executable bin/flow
[100%] Built target flow
real 1m45.692s
user 8m47.195s
sys 0m11.533s
```
after:
```
> touch ../opm/autodiff/BlackoilModelEbos.hpp; time make -j32 flow 2> /dev/null
[ 91%] Built target opmsimulators
Scanning dependencies of target flow
[ 93%] Building CXX object CMakeFiles/flow.dir/flow/flow.cpp.o
[ 95%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_gasoil.cpp.o
[ 97%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_oilwater_polymer.cpp.o
[100%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_polymer.cpp.o
[100%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_oilwater.cpp.o
[100%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_solvent.cpp.o
[100%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_blackoil.cpp.o
[100%] Building CXX object CMakeFiles/flow.dir/flow/flow_ebos_energy.cpp.o
[100%] Linking CXX executable bin/flow
[100%] Built target flow
real 1m21.597s
user 8m49.476s
sys 0m10.973s
```
(this corresponds to a ~20% reduction of the time spend on waiting for
the compiler.)
