def setup_sort(self, index):
"""Setup the sorting algorithm. Index must be a CLVar of CLUInt type with dim=1, e.g. shape=(length,).
The whole Group will be sorted according to the index values.
Input:
index -- the index to sort the group."""
if not index in self._vars:
self.add(index)
#setup vars
self._sortindex = index
self._grid = CLUInt(int(max_reduce(self._sortindex)) + 1)
self._celloffset = CLUInt()
self.add(self._celloffset)
#fillgrid kernel
src = Syncgroup._fgrid_kern_src
src = src.replace('$index', self._sortindex.name)
src = src.replace('$celloffset', self._celloffset.name)
src = src.replace('$grid', self._grid.name)
varlist = [self._sortindex, self._grid, self._celloffset]
self._fillgridkern = CLKernel(src=src, varlist=varlist, name='fgridkern')
self._setup_sortcopy()
self._reset_grid_kern = CLTemplateKernel(src=Syncgroup._reset_grid_str, name='reset_grid')
self._reset_grid_kern.grid = self._grid
self._reset_grid_kern.compile()
self._reset_co_kern = CLTemplateKernel(src=Syncgroup._reset_co_str, name='reset_co')
self._reset_co_kern.celloffset = self._celloffset
self._reset_co_kern.compile()
self._sort_enabeld = True
def sort(self):
"""Sort the group. Sorting must be enabled before. See setup_sort().
Error messages may be unhelpful otherwise, as correct sorting setup is not checked,
when sort() is called (performance reasons)."""
#reset grid (size may change depending on index), reset grid and celloffset to 0
self._grid.set_shape_wo_read( (int(max_reduce(self._sortindex)) + 1,) )
self._reset_grid_kern()
self._reset_co_kern()
#fill grid
self._fillgridkern()
#scan grid
scan_uint(self._grid) # scan on GPU
#sortcopy
self._sortcopykern()
#copy back
self._backcopykern()
