def generate_kernel_ast(builder, statements, declared_temps):
"""Glues together the complete AST for the Slate expression
contained in the :class:`LocalKernelBuilder`.
:arg builder: The :class:`LocalKernelBuilder` containing
all relevant expression information.
:arg statements: A list of COFFEE objects containing all
assembly calls and temporary declarations.
:arg declared_temps: A `dict` containing all previously
declared temporaries.
Return: A `KernelInfo` object describing the complete AST.
"""
slate_expr = builder.expression
if slate_expr.rank == 0:
# Scalars are treated as 1x1 MatrixBase objects
shape = (1, )
else:
shape = slate_expr.shape
# Now we create the result statement by declaring its eigen type and
# using Eigen::Map to move between Eigen and C data structs.
statements.append(ast.FlatBlock("/* Map eigen tensor into C struct */\n"))
result_sym = ast.Symbol("T%d" % len(declared_temps))
result_data_sym = ast.Symbol("A%d" % len(declared_temps))
result_type = "Eigen::Map<%s >" % eigen_matrixbase_type(shape)
result = ast.Decl(ScalarType_c,
ast.Symbol(result_data_sym),
pointers=[("restrict", )])
result_statement = ast.FlatBlock(
"%s %s((%s *)%s);\n" %
(result_type, result_sym, ScalarType_c, result_data_sym))
statements.append(result_statement)
# Generate the complete c++ string performing the linear algebra operations
# on Eigen matrices/vectors
statements.append(ast.FlatBlock("/* Linear algebra expression */\n"))
cpp_string = ast.FlatBlock(slate_to_cpp(slate_expr, declared_temps))
statements.append(ast.Incr(result_sym, cpp_string))
# Generate arguments for the macro kernel
args = [
result,
ast.Decl(ScalarType_c,
builder.coord_sym,
pointers=[("restrict", )],
qualifiers=["const"])
]
# Orientation information
if builder.oriented:
args.append(
ast.Decl("int",
builder.cell_orientations_sym,
pointers=[("restrict", )],
qualifiers=["const"]))
# Coefficient information
expr_coeffs = slate_expr.coefficients()
for c in expr_coeffs:
args.extend([
ast.Decl(ScalarType_c,
csym,
pointers=[("restrict", )],
qualifiers=["const"]) for csym in builder.coefficient(c)
])
# Facet information
if builder.needs_cell_facets:
f_sym = builder.cell_facet_sym
f_arg = ast.Symbol("arg_cell_facets")
f_dtype = as_cstr(cell_to_facets_dtype)
# cell_facets is locally a flattened 2-D array. We typecast here so we
# can access its entries using standard array notation.
cast = "%s (*%s)[2] = (%s (*)[2])%s;\n" % (f_dtype, f_sym, f_dtype,
f_arg)
statements.insert(0, ast.FlatBlock(cast))
args.append(
ast.Decl(f_dtype,
f_arg,
pointers=[("restrict", )],
qualifiers=["const"]))
# NOTE: We need to be careful about the ordering here. Mesh layers are
# added as the final argument to the kernel
# and the amount of layers before that.
if builder.needs_mesh_layers:
args.append(
ast.Decl("int",
builder.mesh_layer_count_sym,
pointers=[("restrict", )],
qualifiers=["const"]))
args.append(ast.Decl("int", builder.mesh_layer_sym))
# Cell size information
if builder.needs_cell_sizes:
args.append(
ast.Decl(ScalarType_c,
builder.cell_size_sym,
pointers=[("restrict", )],
qualifiers=["const"]))
# Macro kernel
macro_kernel_name = "pyop2_kernel_compile_slate"
stmts = ast.Block(statements)
macro_kernel = ast.FunDecl("void",
macro_kernel_name,
args,
stmts,
pred=["static", "inline"])
# Construct the final ast
kernel_ast = ast.Node(builder.templated_subkernels + [macro_kernel])
# Now we wrap up the kernel ast as a PyOP2 kernel and include the
# Eigen header files
include_dirs = list(builder.include_dirs)
include_dirs.append(EIGEN_INCLUDE_DIR)
op2kernel = op2.Kernel(
kernel_ast,
macro_kernel_name,
cpp=True,
include_dirs=include_dirs,
headers=['#include <Eigen/Dense>', '#define restrict __restrict'])
op2kernel.num_flops = builder.expression_flops + builder.terminal_flops
# Send back a "TSFC-like" SplitKernel object with an
# index and KernelInfo
kinfo = KernelInfo(kernel=op2kernel,
integral_type=builder.integral_type,
oriented=builder.oriented,
subdomain_id="otherwise",
domain_number=0,
coefficient_map=slate_expr.coeff_map,
needs_cell_facets=builder.needs_cell_facets,
pass_layer_arg=builder.needs_mesh_layers,
needs_cell_sizes=builder.needs_cell_sizes)
return kinfo
def compile_coordinate_element(ufl_coordinate_element,
contains_eps,
parameters=None):
"""Generates C code for changing to reference coordinates.
:arg ufl_coordinate_element: UFL element of the coordinates
:returns: C code as string
"""
if parameters is None:
parameters = tsfc.default_parameters()
else:
_ = tsfc.default_parameters()
_.update(parameters)
parameters = _
# Create FInAT element
element = tsfc.finatinterface.create_element(ufl_coordinate_element)
cell = ufl_coordinate_element.cell()
extruded = isinstance(cell, ufl.TensorProductCell)
code = {
"geometric_dimension":
cell.geometric_dimension(),
"topological_dimension":
cell.topological_dimension(),
"inside_predicate":
inside_check(element.cell, eps=contains_eps),
"to_reference_coords":
to_reference_coordinates(ufl_coordinate_element, parameters),
"init_X":
init_X(element.cell, parameters),
"max_iteration_count":
1 if is_affine(ufl_coordinate_element) else 16,
"convergence_epsilon":
1e-12,
"dX_norm_square":
dX_norm_square(cell.topological_dimension()),
"X_isub_dX":
X_isub_dX(cell.topological_dimension()),
"extruded_arg":
", int const *__restrict__ layers" if extruded else "",
"extr_comment_out":
"//" if extruded else "",
"non_extr_comment_out":
"//" if not extruded else "",
"IntType":
as_cstr(IntType),
"ScalarType":
ScalarType_c,
}
evaluate_template_c = """#include <math.h>
struct ReferenceCoords {
%(ScalarType)s X[%(geometric_dimension)d];
};
static inline void to_reference_coords_kernel(void *result_, double *x0, int *return_value, %(ScalarType)s *C)
{
struct ReferenceCoords *result = (struct ReferenceCoords *) result_;
/*
* Mapping coordinates from physical to reference space
*/
%(ScalarType)s *X = result->X;
%(init_X)s
int converged = 0;
for (int it = 0; !converged && it < %(max_iteration_count)d; it++) {
%(ScalarType)s dX[%(topological_dimension)d] = { 0.0 };
%(to_reference_coords)s
if (%(dX_norm_square)s < %(convergence_epsilon)g * %(convergence_epsilon)g) {
converged = 1;
}
%(X_isub_dX)s
}
// Are we inside the reference element?
*return_value = %(inside_predicate)s;
}
static inline void wrap_to_reference_coords(
void* const result_, double* const x, int* const return_value, %(IntType)s const start, %(IntType)s const end%(extruded_arg)s,
%(ScalarType)s const *__restrict__ coords, %(IntType)s const *__restrict__ coords_map);
int to_reference_coords(void *result_, struct Function *f, int cell, double *x)
{
int return_value = 0;
%(extr_comment_out)swrap_to_reference_coords(result_, x, &return_value, cell, cell+1, f->coords, f->coords_map);
return return_value;
}
int to_reference_coords_xtr(void *result_, struct Function *f, int cell, int layer, double *x)
{
int return_value = 0;
%(non_extr_comment_out)sint layers[2] = {0, layer+2}; // +2 because the layer loop goes to layers[1]-1, which is nlayers-1
%(non_extr_comment_out)swrap_to_reference_coords(result_, x, &return_value, cell, cell+1, layers, f->coords, f->coords_map);
return return_value;
}
"""
return evaluate_template_c % code
def to_reference_coordinates(ufl_coordinate_element, parameters=None):
if parameters is None:
parameters = tsfc.default_parameters()
else:
_ = tsfc.default_parameters()
_.update(parameters)
parameters = _
# Create FInAT element
element = tsfc.finatinterface.create_element(ufl_coordinate_element)
cell = ufl_coordinate_element.cell()
code = {
"geometric_dimension":
cell.geometric_dimension(),
"topological_dimension":
cell.topological_dimension(),
"to_reference_coords":
to_reference_coordinates_body(ufl_coordinate_element, parameters),
"init_X":
init_X(element.cell, parameters),
"max_iteration_count":
1 if is_affine(ufl_coordinate_element) else 16,
"convergence_epsilon":
1e-12,
"dX_norm_square":
dX_norm_square(cell.topological_dimension()),
"X_isub_dX":
X_isub_dX(cell.topological_dimension()),
"IntType":
as_cstr(IntType),
}
evaluate_template_c = """#include <math.h>
#include <stdio.h>
#include <petsc.h>
static inline void to_reference_coords_kernel(PetscScalar *X, const PetscScalar *x0, const PetscScalar *C)
{
const int space_dim = %(geometric_dimension)d;
/*
* Mapping coordinates from physical to reference space
*/
%(init_X)s
double x[space_dim];
int converged = 0;
for (int it = 0; !converged && it < %(max_iteration_count)d; it++) {
double dX[%(topological_dimension)d] = { 0.0 };
%(to_reference_coords)s
if (%(dX_norm_square)s < %(convergence_epsilon)g * %(convergence_epsilon)g) {
converged = 1;
}
%(X_isub_dX)s
}
}"""
return evaluate_template_c % code
def compile_element(expression, coordinates, parameters=None):
"""Generates C code for point evaluations.
:arg expression: UFL expression
:arg coordinates: coordinate field
:arg parameters: form compiler parameters
:returns: C code as string
"""
if parameters is None:
parameters = default_parameters()
else:
_ = default_parameters()
_.update(parameters)
parameters = _
# No arguments, please!
if extract_arguments(expression):
return ValueError("Cannot interpolate UFL expression with Arguments!")
# Apply UFL preprocessing
expression = tsfc.ufl_utils.preprocess_expression(
expression, complex_mode=utils.complex_mode)
# Collect required coefficients
coefficient, = extract_coefficients(expression)
# Point evaluation of mixed coefficients not supported here
if type(coefficient.ufl_element()) == MixedElement:
raise NotImplementedError("Cannot point evaluate mixed elements yet!")
# Replace coordinates (if any)
domain = expression.ufl_domain()
assert coordinates.ufl_domain() == domain
# Initialise kernel builder
builder = firedrake_interface.KernelBuilderBase(utils.ScalarType_c)
builder.domain_coordinate[domain] = coordinates
x_arg = builder._coefficient(coordinates, "x")
f_arg = builder._coefficient(coefficient, "f")
# TODO: restore this for expression evaluation!
# expression = ufl_utils.split_coefficients(expression, builder.coefficient_split)
# Translate to GEM
cell = domain.ufl_cell()
dim = cell.topological_dimension()
point = gem.Variable('X', (dim, ))
point_arg = ast.Decl(utils.ScalarType_c, ast.Symbol('X', rank=(dim, )))
config = dict(interface=builder,
ufl_cell=coordinates.ufl_domain().ufl_cell(),
point_indices=(),
point_expr=point,
scalar_type=utils.ScalarType)
# TODO: restore this for expression evaluation!
# config["cellvolume"] = cellvolume_generator(coordinates.ufl_domain(), coordinates, config)
context = tsfc.fem.GemPointContext(**config)
# Abs-simplification
expression = tsfc.ufl_utils.simplify_abs(expression, utils.complex_mode)
# Translate UFL -> GEM
translator = tsfc.fem.Translator(context)
result, = map_expr_dags(translator, [expression])
tensor_indices = ()
if expression.ufl_shape:
tensor_indices = tuple(gem.Index() for s in expression.ufl_shape)
return_variable = gem.Indexed(gem.Variable('R', expression.ufl_shape),
tensor_indices)
result_arg = ast.Decl(utils.ScalarType_c,
ast.Symbol('R', rank=expression.ufl_shape))
result = gem.Indexed(result, tensor_indices)
else:
return_variable = gem.Indexed(gem.Variable('R', (1, )), (0, ))
result_arg = ast.Decl(utils.ScalarType_c, ast.Symbol('R', rank=(1, )))
# Unroll
max_extent = parameters["unroll_indexsum"]
if max_extent:
def predicate(index):
return index.extent <= max_extent
result, = gem.optimise.unroll_indexsum([result], predicate=predicate)
# Translate GEM -> COFFEE
result, = gem.impero_utils.preprocess_gem([result])
impero_c = gem.impero_utils.compile_gem([(return_variable, result)],
tensor_indices)
body = generate_coffee(impero_c, {}, utils.ScalarType)
# Build kernel tuple
kernel_code = builder.construct_kernel(
"evaluate_kernel", [result_arg, point_arg, x_arg, f_arg], body)
# Fill the code template
extruded = isinstance(cell, TensorProductCell)
code = {
"geometric_dimension": cell.geometric_dimension(),
"layers_arg": ", int const *__restrict__ layers" if extruded else "",
"layers": ", layers" if extruded else "",
"extruded_define": "1" if extruded else "0",
"IntType": as_cstr(IntType),
"scalar_type": utils.ScalarType_c,
}
# if maps are the same, only need to pass one of them
if coordinates.cell_node_map() == coefficient.cell_node_map():
code[
"wrapper_map_args"] = "%(IntType)s const *__restrict__ coords_map" % code
code["map_args"] = "f->coords_map"
else:
code[
"wrapper_map_args"] = "%(IntType)s const *__restrict__ coords_map, %(IntType)s const *__restrict__ f_map" % code
code["map_args"] = "f->coords_map, f->f_map"
evaluate_template_c = """
static inline void wrap_evaluate(%(scalar_type)s* const result, %(scalar_type)s* const X, %(IntType)s const start, %(IntType)s const end%(layers_arg)s,
%(scalar_type)s const *__restrict__ coords, %(scalar_type)s const *__restrict__ f, %(wrapper_map_args)s);
int evaluate(struct Function *f, double *x, %(scalar_type)s *result)
{
struct ReferenceCoords reference_coords;
%(IntType)s cell = locate_cell(f, x, %(geometric_dimension)d, &to_reference_coords, &to_reference_coords_xtr, &reference_coords);
if (cell == -1) {
return -1;
}
if (!result) {
return 0;
}
#if %(extruded_define)s
int layers[2] = {0, 0};
int nlayers = f->n_layers;
layers[1] = cell %% nlayers + 2;
cell = cell / nlayers;
#endif
wrap_evaluate(result, reference_coords.X, cell, cell+1%(layers)s, f->coords, f->f, %(map_args)s);
return 0;
}
"""
return (evaluate_template_c % code) + kernel_code.gencode()
