Scatter in worklets
Add the functionality to perform a scatter operation from input to output in a worklet invocation. This allows you to, for example, specify a variable amount of outputs generated for each input.
See merge request !221
I noticed a failure in a dashboard run of UnitTestParametricCoordinates.
This test uses randomly generated numbers to test the behavior of some
cell shapes, and there was an instance that occured with seed 1447261681
that caused one of the comparisons to be just slightly larger than the
default tolerance but still within reasonable value.
I just increased the tolerance of that particular comparison. Hopefully
this will prevent all future failures.
The original workaround for inclusive_scan bugs in thrust 1.8 only solved the
issue for basic arithmetic types such as int, float, double. Now we go one
step further and fix the problem for all types.
The solution is to provide a proper implementation of destructive_accumulate_n
and make sure it exists before any includes of thrust occur.
Recent changes to algorithm implementations caused CellDerivative to be
called in a way such that it gave conversion warnings on some compilers.
Fix that.
This has been requested on the mailing list to make it easier to
interpolate integer vectors.
There are a couple of downsides to this addition. First, it implicitly
casts doubles back to whatever the vector type is, which can cause a
loss of precision. Second, it makes it more likely to get overload
errors when multiplying with Vec. In particular, the operator to cast
Vec of size 1 to the component class had to be removed.
The tetrahedralize algorithms have been changed to use the Scatter
classes to build indices rather than build them on their own.
To implement this efficiently with structured grids, a new ScatterUniform
class was made. I also added a new execution argument tag that allows
you to get the thread indices object from within the worklet.
Previously, each VecFromPortalPermute (the type that held the from field
values) held its own copy of the indices. For point to cell on
structured grids, this was a lot of repeated data values, which has the
potential to fill up cache and registers. Instead, just use pointer
references.
Previously, there was a declaration ConstArrayPortalFromThrust<const T>
in ArrayManagerExecutionThrustDevice. This proved problematic because
values read from the array in the worklet were typed as const T rather
than simply T. Any Vec or Matrix built from that type would then fail
because they are not meant to work with a const value (which means they
have to be set on construction and never changed.
Instead, declare ConstArrayPortalFromThrust<T> and internally set all
the Thrust pointers to have type const T. Also declare other thrust
pointers used as method parameters to have const T rather than T. This
should work as conversion from T to const T should be fine, but not the
other way around.
This changes the interface to the ThreadIndices classes to have both
input and output indices. It also adds a visit index to ThreadIndices.
Also added the VisitIndex execution signature tag, which relies on this
behavior.
This now allows for even more efficient construction of uniform point
coordinates when running under the 3d scheduler, since we don't need to go
from 3d index to flat index to 3d index, instead we stay in 3d index
Previously, all Fetch objects received an Invocation object in their
Load and Store methods. The point of this was that it allowed the Fetch
to get data from any of the execution objects. However, every Fetch
either just got data directly from its associated execution object or
else used a secondary execution object (the input domain) to get indices
into their own execution object.
This left two potential areas for improvement. First, pulling data out
of the Invocation object was unnecessarily complicated. It would be much
nicer to get data directly from the associated execution object. Second,
when getting index information from the input domain, it was often the
case that extra computations were necessary (particularly on structured
cell sets). There was no way to share the index information among
Fetches, and therefore the computations were replicated.
This change removes the Invocation from the Fetch Load and Store.
Instead, it passes the associated execution object and a new object type
called the ThreadIndices. The ThreadIndices are customized for the input
domain and therefore have all the information needed for a redirected
lookup. It is also a thread-local object so it can cache computed
indices and save on computation time.
When you create a CellSetPermutation you provide an array of the cell ids that
you want to iterate. This allows the user to do custom blanking of a data set,
or to do multi iteration over a set of cells.
Xcode 7 warnings
The XCode 7 compiler has a new warning for unused typedefs. The Boost code we use has some instances where this warning gets issued. Suppress these warnings.
See merge request !199
This is to be used in place of BOOST_STATIC_ASSERT so that we can
control its implementation.
The implementation is designed to fix the issue where the latest XCode
clang compiler gives a warning about a unused typedefs when the boost
static assert is used within a function. (This warning also happens when
using the C++11 static_assert keyword.) You can suppress this warning
with _Pragma commands, but _Pragma commands inside a block is not
supported in GCC. The implementation of VTKM_STATIC_ASSERT handles all
current cases.
fd685210 Always install all device headers even when device isn't enabled.
b1663b24 Add an example of using multiple backends from a single translation unit.
fc0ff69d Methods with try/catch need to be host only.
4d635d64 DeviceAdapter Tags now always exist, and contain if the device is valid.
cf32b430 Teach Configure.h to store if TBB and CUDA are enabled.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Kenneth Moreland <kmorel@sandia.gov>
Merge-request: !198
The boost assert macros seem to have an issue where they define an
unused typedef. This is causing the XCode 7 compiler to issue a warning.
Since the offending code is in a macro, the warning is identified with
the VTK-m header even though the code is in boost. To get around this,
wrap all uses of the boost assert that is causing the warning in the
third party pre/post macros to disable the warning.
When ExecutionWholeArray is passed to a worklet, it is expected to
behave like an array portal. However, it was missing the
GetNumberOfValues method and the ValueType typedef. These are now added.
By introducing our own custom thrust execution policy we can make sure
to hit the fastest code paths in thrust for the sort operation. This makes
sure that for UInt32,Int32, and Float32 we use the radix sort from thrust
which offers a 2x to 3x speed improvement over the merge sort implementation.
Secondly by telling thrust that our BinaryOperators are commutative we
make sure that we get the fastest code paths when executing Inclusive
and Exclusive Scan
Benchmark 'Radix Sort on 1048576 random values vtkm::Int32' results:
median = 0.0117049s
median abs dev = 0.00324614s
mean = 0.0167615s
std dev = 0.00786269s
min = 0.00845875s
max = 0.0389063s
Benchmark 'Radix Sort on 1048576 random values vtkm::Float32' results:
median = 0.0234463s
median abs dev = 0.000317249s
mean = 0.021452s
std dev = 0.00470307s
min = 0.011255s
max = 0.0250643s
Benchmark 'Merge Sort on 1048576 random values vtkm::Int32' results:
median = 0.0310486s
median abs dev = 0.000182129s
mean = 0.0286914s
std dev = 0.00634102s
min = 0.0116225s
max = 0.0317379s
Benchmark 'Merge Sort on 1048576 random values vtkm::Float32' results:
median = 0.0310617s
median abs dev = 0.000193583s
mean = 0.0295779s
std dev = 0.00491531s
min = 0.0147257s
max = 0.032307s
In the special case where you are loading the point coordinates for a
structured grid in a point to cell map (an important use case), create a
VecRectilinearPointCoordinates rather than build a Vec of the values.
This will activate the cell specalizations in previous commits.
These changes also added some flat-to-logical index conversion and vice
versa in ConnectivityStructuredInternals. This change also fixed a bug
in getting cells attached to points in 2D grids. (Actually, technically
someone else fixed it and checked it in first. The changes were merged
during a rebase.)
I also added a specalization to Vec for 1D that implicitly converts
between the 1D Vec and the component. This can be convenient when
templating on the Vec length.
There are several switch statements in ParametricCoordinates.h that have
a default clause that is an error condition. The code was simply calling
the RaiseError method on the worklet before quiting. Although the
behavior is supposed to be similar to throwing an exception, flow
actually does still continue. These error default clauses kept going
without breaking from the switch or initializing the variables the
method is supposed to set. Although the values should not matter once
the error is raised, I was getting compiler warnings about it. It's also
bad practice as certain NaN values can cause the program to signal out,
so it is best to set the data to something.
These cell types are inherited from VTK, but they are basically the same
as quad and hexahedron, respectively. The only useful difference is that
pixel and voxel are supposed to be axis aligned, but you cannot
determine that by the cell shape alone (at least not just from the cell
set).
A big issue with these is that their indexing is different that of quad
and hex. The development team had a long discussion about the benefits
of the alternate indexing, but after consulting with Berk Geveci and
Will Schroder from the VTK team, that indexing is not really taken
advantage of at the cell level. Thus, it is really just a nuisance in
VTK-m.
The original way was overconstrained with respect to the number of
parametric coordinates.
Also implemented WorldCoordinatesToParametricCoordinates for polygons.
The general polygon version is not implemented yet because I need to
change the way it is interpolated.
To get wedge to work correctly, I had to change the interpolation
slightly there. Previously the interpolation had a singularity at
the tip.
The functions for doing interpolations and derivatives were called
CellInterpolate and CellDerivative, but the file names were
Interpolate.h and Derivative. Now the files are CellInterpolate.h and
CellDerivative.h so they are more consistent and a bit easier to find.
The interpolate and derivative functions has the shape tag at end of the
function arguments (just before the "worklet" parameter, which is just
the error handling mechanism). However, the parametric coordinate
functions had the shape tag at the beginning. Moved the shape tag to the
end to be more consistent within these functions and also in other uses
throughtout VTK-m.
Previously, when you requested a CellShape in the ExecutionSignature,
you just got an ID stored in a vtkm::IdComponent. This change returns a
cell shape tag of the appropriate type (or generic if the type is not
known at compile time). This will allow functions called from the
worklet to specialize on the cell type better.
