def create_derivative(f: NativeFunction, formula: str, var_names: Tuple[str, ...]) -> Derivative:
original_formula = formula
arguments: List[NamedCType] = [a.nctype.remove_const_ref() for a in cpp_arguments(f)]
return_names = tuple(n if n != 'self' else 'result' for n in cpp.return_names(f))
return_types = tuple(cpp.return_type(r).remove_const_ref() for r in f.func.returns)
named_returns = [NamedCType(name, type) for name, type in zip(return_names, return_types)]
formula, saved_inputs = saved_variables(formula, arguments, var_names)
formula, saved_outputs = saved_variables(formula, named_returns, var_names)
# Check that the referenced derivatives in the formula are in bounds
for i in used_gradient_indices(formula):
if i >= len(f.func.returns):
raise RuntimeError(
f'Out of bounds grads access: derivative formula for {cpp.name(f.func)} '
f'used grads[{i}], but the forward only returns {len(f.func.returns)} outputs.'
)
return Derivative(
formula=formula,
original_formula=original_formula,
var_names=var_names,
saved_inputs=saved_inputs,
saved_outputs=saved_outputs,
)
def create_derivative(f: NativeFunction, formula: str,
var_names: Tuple[str, ...]) -> Derivative:
arguments = cpp_arguments(f)
argument_names = tuple(a.name for a in arguments)
argument_types = tuple(a.type for a in arguments)
return_names = tuple(n if n != 'self' else 'result'
for n in cpp.return_names(f))
return_types = tuple(cpp.return_type(r) for r in f.func.returns)
formula, saved_inputs = saved_variables(formula, argument_names,
argument_types, var_names)
formula, saved_outputs = saved_variables(formula, return_names,
return_types, var_names)
# Check that the referenced derivatives in the formula are in bounds
for i in used_gradient_indices(formula):
if i >= len(f.func.returns):
raise RuntimeError(
f'Out of bounds grads access: derivative formula for {cpp.name(f.func)} '
f'used grads[{i}], but the forward only returns {len(f.func.returns)} outputs.'
)
return Derivative(
formula=formula,
var_names=var_names,
saved_inputs=saved_inputs,
saved_outputs=saved_outputs,
)