def step_statements(self, stage, f, dt, rhs):
fq = [index_fields(f, prepend_with=(q, )) for q in range(2)]
if stage == 0:
return {fq[1]: fq[0] + dt * rhs, fq[0]: fq[0] + dt / 2 * rhs}
elif stage == 1:
return {fq[0]: fq[0] + dt / 2 * rhs}
def step_statements(self, stage, f, dt, rhs):
fq = [index_fields(f, prepend_with=(q, )) for q in range(3)]
if stage == 0:
return {fq[1]: fq[0] + dt * rhs}
elif stage == 1:
return {fq[1]: 3 / 4 * fq[0] + 1 / 4 * fq[1] + dt / 4 * rhs}
elif stage == 2:
return {fq[0]: 1 / 3 * fq[0] + 2 / 3 * fq[1] + dt * 2 / 3 * rhs}
def make_steps(self, MapKernel=ElementWiseMap, **kwargs):
rhs = var("rhs")
dt = var("dt")
q = var("q")
fixed_parameters = kwargs.pop("fixed_parameters", dict())
rhs_statements = {
rhs[i]: index_fields(value, prepend_with=(q, ))
for i, value in enumerate(self.rhs_dict.values())
}
steps = []
for stage in range(self.num_stages):
RK_dict = {}
for i, f in enumerate(self.rhs_dict.keys()):
# ensure that key is either a Field or a Subscript of a Field
# so that index_fields can prepend the q index
key_has_field = False
if isinstance(f, Field):
key_has_field = True
elif isinstance(f, Subscript):
if isinstance(f.aggregate, Field):
key_has_field = True
if not key_has_field:
raise ValueError("rhs_dict keys must be Field instances")
statements = self.step_statements(stage, f, dt, rhs[i])
for k, v in statements.items():
RK_dict[k] = v
fixed_parameters.update(q=0 if stage == 0 else 1)
options = lp.Options(enforce_variable_access_ordered="no_check")
step = MapKernel(RK_dict,
tmp_instructions=rhs_statements,
args=self.args,
**kwargs,
options=options,
fixed_parameters=fixed_parameters)
steps.append(step)
return steps
def make_kernel(self, map_instructions, tmp_instructions, args, domains,
**kwargs):
temp_statements = []
temp_vars = []
from pystella.field import index_fields
indexed_tmp_insns = index_fields(tmp_instructions)
indexed_map_insns = index_fields(map_instructions)
for statement in indexed_tmp_insns:
if isinstance(statement, lp.InstructionBase):
temp_statements += [statement]
else:
assignee, expression = statement
# only declare temporary variables once
if isinstance(assignee, pp.Variable):
current_tmp = assignee
elif isinstance(assignee, pp.Subscript):
current_tmp = assignee.aggregate
else:
current_tmp = None
if current_tmp is not None and current_tmp not in temp_vars:
temp_vars += [current_tmp]
tvt = lp.Optional(None)
else:
tvt = lp.Optional()
temp_statements += [
self._assignment(assignee, expression, temp_var_type=tvt)
]
output_statements = []
for statement in indexed_map_insns:
if isinstance(statement, lp.InstructionBase):
output_statements += [statement]
else:
assignee, expression = statement
temp_statements += [self._assignment(assignee, expression)]
options = kwargs.pop("options", lp.Options())
# ignore lack of supposed dependency for single-instruction kernels
if len(map_instructions) + len(tmp_instructions) == 1:
options.check_dep_resolution = False
from pystella import get_field_args
inferred_args = get_field_args([map_instructions, tmp_instructions])
all_args = append_new_args(args, inferred_args)
t_unit = lp.make_kernel(
domains,
temp_statements + output_statements,
all_args + [lp.ValueArg("Nx, Ny, Nz", dtype="int"), ...],
options=options,
**kwargs,
)
new_args = []
knl = t_unit.default_entrypoint
for arg in knl.args:
if isinstance(arg, lp.KernelArgument) and arg.dtype is None:
new_arg = arg.copy(dtype=self.dtype)
new_args.append(new_arg)
else:
new_args.append(arg)
t_unit = t_unit.with_kernel(knl.copy(args=new_args))
t_unit = lp.remove_unused_arguments(t_unit)
t_unit = lp.register_callable(t_unit, "round",
UnaryOpenCLCallable("round"))
return t_unit