TMBad::global::Operator< ninput_, noutput_ > Struct Template Reference

Operator with input/output dimension known at compile time. More...

#include <global.hpp>

Public Member Functions
void	dependencies_updating (Args<> &args, Dependencies &dep) const
	Default implementation of OperatorPure::dependencies_updating()
void *	operator_data ()
	Return operator specific dynamic information (optional)
OperatorPure *	other_fuse (OperatorPure *self, OperatorPure *other)
	How to fuse this operator (self) with another (other)
void	print (print_config cfg)
	Print this operator (optional)

Static Public Attributes
static const bool	add_forward_replay_copy = false
	Should this operator replay it self by invoking the copy CTOR ?
static const bool	add_static_identifier = false
	Should this operator have a static identifier ?
static const bool	allow_remap = true
	Is it safe to remap the inputs of this operator? More...
static const int	dependent_variable = false
	Is output of this operator a dependent variable ?
static const bool	dynamic = false
	Does this operator require dynamic allocation ?
static const bool	elimination_protected = false
	Protect this operator from elimination by the tape optimizer ?
static const bool	have_dependencies = false
	Have dependencies member been defined ?
static const bool	have_eval = false
	Does this class have an eval member from which to define forward ?
static const bool	have_forward_incr_reverse_decr = false
	Have forward_incr and reverse_incr members been defined ?
static const bool	have_forward_mark_reverse_mark = false
	Have forward_mark and reverse_mark members been defined ?
static const bool	have_forward_reverse = true
	Have forward and reverse members been defined ?
static const bool	have_increment_decrement = false
	Have increment and decrement members been defined ?
static const bool	have_input_size_output_size = false
	Have input_size and output_size members been defined ?
static const bool	implicit_dependencies = false
	Does this operator have implicit dependencies? More...
static const int	independent_variable = false
	Is output of this operator an independent variable ?
static const bool	is_constant = false
	Is this a constant operator ?
static const bool	is_linear = false
	Is this a linear operator ?
static const int	max_fuse_depth = 2
	How many times can this operator be doubled ?
static const int	ninput = ninput_
	Number of operator inputs.
static const int	noutput = noutput_
	Number of operator outputs.
static const bool	smart_pointer = false
	Is this operator a 'smart pointer' (with reference counting) ?
static const bool	updating = false
	This operator may update existing variables ? More...

Detailed Description

template<int ninput_, int noutput_ = 1>
struct TMBad::global::Operator< ninput_, noutput_ >

Operator with input/output dimension known at compile time.

Definition at line 1491 of file global.hpp.

Member Data Documentation

allow_remap

template<int ninput_, int noutput_ = 1>

const bool TMBad::global::Operator< ninput_, noutput_ >::allow_remap = true

static

Is it safe to remap the inputs of this operator?

In general it is illegal to remap operators that assume a certain memory layout of its inputs, e.g. BLAS routines. Make sure to set to false for those cases.

Definition at line 1519 of file global.hpp.

implicit_dependencies

template<int ninput_, int noutput_ = 1>

const bool TMBad::global::Operator< ninput_, noutput_ >::implicit_dependencies = false

static

Does this operator have implicit dependencies?

Signify that this operator uses indirect inputs

• and that all these inputs are available through the dependencies() function (in particular have_dependencies must be true in this case)
• and that these indirect dependencies should be used to auto implement the marker routines forward_mark_reverse_mark.

  Note

  FIXME: I think allow_remap can eventually be deprecated?

Definition at line 1530 of file global.hpp.

updating

template<int ninput_, int noutput_ = 1>

const bool TMBad::global::Operator< ninput_, noutput_ >::updating = false

static

This operator may update existing variables ?

An 'updating' operator is allowed to update (increment/decrement) certain ('updatable') variables already on the tape. In general this property breaks basic principles of reverse mode AD unless the following extra requirement is satisfied:

• Once an updatable variable have been read it may no longer be updated.

This requrement always holds for the derivative variables during reverse replay. We note that 'updating' operators are considered an extension to the standard AD framework. In particular, a more complex dependency anlysis is required:

• Updating operators must have implicit_dependencies=true.
• The updating flag must be inherited by derivatives.
• The updating flag signifies that necessary derivative workspaces are added to the tape prior to any reverse replay.
• An updating operator must implement the member dependencies_updating() defining which variables are updated.

Definition at line 1574 of file global.hpp.

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The documentation for this struct was generated from the following file:

• global.hpp