def _visit_homogenous_space(self, node):
offset_versions = []
# so that we can apply all of the spaces simultaneously
for space in node.space.spaces:
cp = copy.deepcopy(node.body)
shifter = StencilShifter(space.low)
output = [shifter.visit(part) for part in cp]
offset_versions.extend(output)
low = Vector((0,) * node.space.ndim)
high = node.space.spaces[0].high - node.space.spaces[0].low
stride = node.space.spaces[0].stride
return IterationSpace(
space=NDSpace([Space(low, high, stride)]),
body=offset_versions
)
def create_component(ndim, dim):
# each component is one dimension -> A[i] = B[i](A[i] - A[i-1]) + B[i+1](A[i+1] - A[i])
lower_diff = StencilComponent("mesh",
SparseWeightArray({Vector.zero_vector(ndim): 1, -Vector.unit_vector(dim, ndim): -1}))
lower_diff *= StencilComponent("beta_{}".format(dim),
SparseWeightArray({Vector.zero_vector(ndim): 1}))
upper_diff = StencilComponent("mesh",
SparseWeightArray({Vector.zero_vector(ndim): -1, Vector.unit_vector(dim, ndim): 1}))
upper_diff *= StencilComponent("beta_{}".format(dim),
SparseWeightArray({Vector.unit_vector(dim, ndim): 1}))
return lower_diff + upper_diff
def test_boundaries():
"""
Tests if boundaries can be parallelized (or not).
"""
dimensions = 3
def reference_vector(vec):
first_nonzero_position = next(i for i in range(len(vec)) if vec[i])
return -vec * Vector.unit_vector(first_nonzero_position, len(vec))
def get_stencil(boundary): # boundaries of 1-norm n depend on boundaries of 1-norm n-1 by looking in on the first non-zero element.
read_vector = reference_vector(boundary)
component = StencilComponent(
'mesh',
SparseWeightArray(
{
read_vector: 1
}
)
)
return Stencil(component, 'mesh', [
(-1, 0, 1) if bound == 1 else (0, 1, 1) if bound == -1 else (1, -1, 1)
for bound in boundary
])
stencils = [
(boundary, get_stencil(boundary)) for boundary in Vector.moore_vectors(dimensions)
]
group = StencilGroup([stencil for bound, stencil in stencils])
serial = create_dependency_graph(group, {"mesh": (32,)*dimensions})
parallel = create_parallel_graph(group, {"mesh": (32,)*dimensions})
# print(serial)
# print(parallel)
# print(serial == parallel)
# exit()
for (b1, s1), (b2, s2) in itertools.product(stencils, repeat=2):
has_conflict = b2+reference_vector(b2) == b1 or b1 == b2
graph_conflict = serial[hash(s2)][hash(s1)]
parallel_conflict = parallel[hash(s2)][hash(s1)]
reported = stencil_conflict(s1, s2, shape_map={"mesh": (32,)*dimensions})
print(b1, b2, reported, has_conflict, graph_conflict, parallel_conflict, '*'*10*(parallel_conflict != has_conflict))
def run_affine():
weight_array = SparseWeightArray(
{Vector.index_vector(3) + (1, 1, 1) : 5}
)
component = StencilComponent(
"input",
weight_array
)
stencil = Stencil(
component,
"output",
[(1, -1, 1)]*3
)
compiler = PythonCompiler()
kern = compiler.compile(stencil)
arr = np.arange(6**3, dtype=np.float).reshape((6, 6, 6))
out = np.zeros_like(arr)
kern(out, arr)
print(out)
def _stencil_conflict(data1, data2, shape_map):
# shadows = get_shadow(stencil2) # these are all of the offset vectors for each array
shadows = data2.shadow
if data1.output not in shadows:
return False # not read/writing from same mesh
shade = shadows[data1.output] # these are vectors that are used.
shape = shape_map[data1.primary_mesh]
if data1.output == data2.output: # if they write to the same array
shade |= {Vector.zero_vector(len(shape))}
# Perform exhaustive search over pairs of iteration spaces?
# TODO: Probably should make this smarter
for write_domain in data1.iteration_space.reify(shape).domains:
for read_domain in data2.iteration_space.reify(shape).domains:
# in order to save time, compute the projections for each vector onto each dimension.
collisions = [{} for _ in shape]
for vector in shade:
for dim, val in enumerate(vector):
collisions[dim][val] = False
# using 1d slices of each domain
for wd_1d, rd_1d, offsets in zip(
zip(write_domain.lower, write_domain.upper, write_domain.stride),
zip(read_domain.lower, read_domain.upper, read_domain.stride),
collisions,
):
for offset in offsets:
offsets[offset] = _has_conflict(wd_1d, rd_1d, offset)
# print(collisions)
for vector in shade:
if all(
collisions[dim][val] for dim, val in enumerate(vector)
): # some vector has a collision on all dimensions
return True
return False
def reference_vector(vec):
first_nonzero_position = next(i for i in range(len(vec)) if vec[i])
return -vec * Vector.unit_vector(first_nonzero_position, len(vec))
def test_collision():
"""
Test using Red Black. All of them should collide.
"""
dimensions = 3
# Red domains are formed by the origin plus all non-negative vectors with 1-norm 2.
red_domain_starts = [Vector.zero_vector(dimensions)] + [i for i in Vector.von_neumann_vectors(dimensions, 2)
if all(coord >= 0 for coord in i)]
red_domain = DomainUnion([
RectangularDomain([(s, -1, 2) for s in start])
for start in red_domain_starts
])
# Black domains are formed by non-negative vectors with 1-norm 1.
black_domain_starts = [i for i in Vector.von_neumann_vectors(dimensions, 1) if all(coord >= 0 for coord in i)]
black_domain = DomainUnion([
RectangularDomain([(s, -1, 2) for s in start])
for start in black_domain_starts
])
star_neighborhood = {Vector.unit_vector(d, dimensions): 1 for d in range(dimensions)}
star_neighborhood.update(
{-Vector.unit_vector(d, dimensions): 1 for d in range(dimensions)}
)
red = Stencil(
StencilComponent(
"mesh",
SparseWeightArray(
star_neighborhood
)
),
"mesh",
red_domain
)
black = Stencil(
StencilComponent(
"mesh",
SparseWeightArray(
star_neighborhood
)
),
"mesh",
black_domain
)
red_oop = Stencil(
StencilComponent(
"mesh",
SparseWeightArray(
star_neighborhood
)
),
"output",
red_domain
)
black_oop = Stencil(
StencilComponent(
"mesh",
SparseWeightArray(
star_neighborhood
)
),
"output",
black_domain
)
print("Testing with simulated 32^dimensions mesh")
print("WRITE-READ", "has collision")
print("RED - RED", stencil_conflict(red, red, {"mesh": (32,)*dimensions}))
print("BLACK - BLACK", stencil_conflict(black, black, {"mesh": (32,)*dimensions}))
print("RED - BLACK", stencil_conflict(red, black, {"mesh": (32,)*dimensions}))
print("BLACK - RED", stencil_conflict(black, red, {"mesh": (32,)*dimensions}))
print("REDOOP - BLACKOOP", stencil_conflict(red_oop, black_oop, {"mesh": (32,)*dimensions}))
print("BLACKOOP - REDOOP", stencil_conflict(black_oop, red_oop, {"mesh": (32,)*dimensions}))
print("INTRA-red is valid", validate_stencil(red))
print("INTRA-black is valid", validate_stencil(black))
