Autodiff Codegen Part 1: Expressions

This patch adds the 'Expression' class, which is a fundamental
building block of automatic code generation. The expressions can
be used as scalar types for cost functors as well as Jets.
Dynamic branching is not yet supported.

Change-Id: I8c61bee5c307e0eec20fd39382683ea90f720dff
This commit is contained in:
Darius Rueckert
2019-10-02 12:45:59 +02:00
parent ba62397d80
commit 4247d420fa
10 changed files with 1116 additions and 12 deletions
+203
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
//
//
// This file contains the basic expression type, which is used during code
// generation. Only assignment expressions of the following form are supported:
//
// result = [constant|binary_expr|functioncall]
//
// Examples:
// v_78 = v_28 / v_62;
// v_97 = exp(v_20);
// v_89 = 3.000000;
//
//
#ifndef CERES_PUBLIC_EXPRESSION_H_
#define CERES_PUBLIC_EXPRESSION_H_
#include <string>
#include <vector>
namespace ceres {
namespace internal {
using ExpressionId = int;
static constexpr ExpressionId kInvalidExpressionId = -1;
enum class ExpressionType {
// v_0 = 3.1415;
COMPILE_TIME_CONSTANT,
// For example a local member of the cost-functor.
// v_0 = _observed_point_x;
RUNTIME_CONSTANT,
// Input parameter
// v_0 = parameters[1][5];
PARAMETER,
// Output Variable Assignemnt
// residual[0] = v_51;
OUTPUT_ASSIGNMENT,
// Trivial Assignment
// v_1 = v_0;
ASSIGNMENT,
// Binary Arithmetic Operations
// v_2 = v_0 + v_1
PLUS,
MINUS,
MULTIPLICATION,
DIVISION,
// Unary Arithmetic Operation
// v_1 = -(v_0);
// v_2 = +(v_1);
UNARY_MINUS,
UNARY_PLUS,
// Binary Comparison. (<,>,&&,...)
// This is the only expressions which returns a 'bool'.
// const bool v_2 = v_0 < v_1
BINARY_COMPARISON,
// The !-operator on logical expression.
LOGICAL_NEGATION,
// General Function Call.
// v_5 = f(v_0,v_1,...)
FUNCTION_CALL,
// The ternary ?-operator. Separated from the general function call for easier
// access.
// v_3 = ternary(v_0,v_1,v_2);
TERNARY,
// No Operation. A placeholder for an 'empty' expressions which will be
// optimized out during code generation.
NOP
};
// This class contains all data that is required to generate one line of code.
// Each line has the following form:
//
// lhs = rhs;
//
// The left hand side is the variable name given by its own id. The right hand
// side depends on the ExpressionType. For example, a COMPILE_TIME_CONSTANT
// expressions with id 4 generates the following line:
// v_4 = 3.1415;
//
// Objects of this class are created indirectly using the static CreateXX
// methods. During creation, the Expression objects are added to the
// ExpressionGraph (see expression_graph.h).
class Expression {
public:
// These functions create the corresponding expression, add them to an
// internal vector and return a reference to them.
static ExpressionId CreateCompileTimeConstant(double v);
static ExpressionId CreateRuntimeConstant(const std::string& name);
static ExpressionId CreateParameter(const std::string& name);
static ExpressionId CreateOutputAssignment(ExpressionId v,
const std::string& name);
static ExpressionId CreateAssignment(ExpressionId v);
static ExpressionId CreateBinaryArithmetic(ExpressionType type,
ExpressionId l,
ExpressionId r);
static ExpressionId CreateUnaryArithmetic(ExpressionType type,
ExpressionId v);
static ExpressionId CreateBinaryCompare(const std::string& name,
ExpressionId l,
ExpressionId r);
static ExpressionId CreateLogicalNegation(ExpressionId v);
static ExpressionId CreateFunctionCall(
const std::string& name, const std::vector<ExpressionId>& params);
static ExpressionId CreateTernary(ExpressionId condition,
ExpressionId if_true,
ExpressionId if_false);
// Returns true if the expression type is one of the basic math-operators:
// +,-,*,/
bool IsArithmetic() const;
// If this expression is the compile time constant with the given value.
// Used during optimization to collapse zero/one arithmetic operations.
// b = a + 0; -> b = a;
bool IsCompileTimeConstantAndEqualTo(double constant) const;
// Checks if "other" is identical to "this" so that one of the epxressions can
// be replaced by a trivial assignment. Used during common subexpression
// elimination.
bool IsReplaceableBy(const Expression& other) const;
// Replace this expression by 'other'.
// The current id will be not replaced. That means other experssions
// referencing this one stay valid.
void Replace(const Expression& other);
// If this expression has 'other' as an argument.
bool DirectlyDependsOn(ExpressionId other) const;
// Converts this expression into a NOP
void MakeNop();
private:
// Only ExpressionGraph is allowed to call the constructor, because it manages
// the memory and ids.
friend class ExpressionGraph;
// Private constructor. Use the "CreateXX" functions instead.
Expression(ExpressionType type, ExpressionId id);
ExpressionType type_ = ExpressionType::NOP;
const ExpressionId id_ = kInvalidExpressionId;
// Expressions have different number of arguments. For example a binary "+"
// has 2 parameters and a function call to "sin" has 1 parameter. Here, a
// reference to these paratmers is stored. Note: The order matters!
std::vector<ExpressionId> arguments_;
// Depending on the type this name is one of the following:
// (type == FUNCTION_CALL) -> the function name
// (type == PARAMETER) -> the parameter name
// (type == OUTPUT_ASSIGN) -> the output variable name
// (type == BINARY_COMPARE)-> the comparison symbol "<","&&",...
// else -> unused
std::string name_;
// Only valid if type == COMPILE_TIME_CONSTANT
double value_ = 0;
};
} // namespace internal
} // namespace ceres
#endif
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
#ifndef CERES_PUBLIC_EXPRESSION_TREE_H_
#define CERES_PUBLIC_EXPRESSION_TREE_H_
#include <vector>
#include "expression.h"
namespace ceres {
namespace internal {
// A directed, acyclic, unconnected graph containing all expressions of a
// program.
//
// The expression graph is stored linear in the expressions_ array. The order is
// identical to the execution order. Each expression can have multiple children
// and multiple parents.
// A is child of B <=> B has A as a parameter <=> B.DirectlyDependsOn(A)
// A is parent of B <=> A has B as a parameter <=> A.DirectlyDependsOn(B)
class ExpressionGraph {
public:
// Creates an expression and adds it to expressions_.
// The returned reference will be invalid after this function is called again.
Expression& CreateExpression(ExpressionType type);
// Checks if A depends on B.
// -> B is a descendant of A
bool DependsOn(ExpressionId A, ExpressionId B) const;
Expression& ExpressionForId(ExpressionId id) { return expressions_[id]; }
const Expression& ExpressionForId(ExpressionId id) const {
return expressions_[id];
}
int Size() const { return expressions_.size(); }
private:
// All Expressions are referenced by an ExpressionId. The ExpressionId is the
// index into this array. Each expression has a list of ExpressionId as
// arguments. These references form the graph.
std::vector<Expression> expressions_;
};
// After calling this method, all operations on 'ExpressionRef' objects will be
// recorded into an ExpressionGraph. You can obtain this graph by calling
// StopRecordingExpressions.
//
// Performing expression operations before calling StartRecordingExpressions or
// calling StartRecodring. twice is an error.
void StartRecordingExpressions();
// Stops recording and returns all expressions that have been executed since the
// call to StartRecordingExpressions. The internal ExpressionGraph will be
// invalidated and a second consecutive call to this method results in an error.
ExpressionGraph StopRecordingExpressions();
// Returns a pointer to the active expression tree.
// Normal users should not use this functions.
ExpressionGraph* GetCurrentExpressionGraph();
} // namespace internal
} // namespace ceres
#endif
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
//
// TODO: Documentation
#ifndef CERES_PUBLIC_EXPRESSION_REF_H_
#define CERES_PUBLIC_EXPRESSION_REF_H_
#include <string>
#include "ceres/jet.h"
#include "expression.h"
namespace ceres {
namespace internal {
// This class represents a scalar value that creates new expressions during
// evaluation. ExpressionRef can be used as template parameter for cost functors
// and Jets.
//
// ExpressionRef should be passed by value.
struct ExpressionRef {
ExpressionRef() = default;
// Create a compile time constant expression directly from a double value.
// This is important so that we can write T(3.14) in our code and
// it's automatically converted to the correct expression.
explicit ExpressionRef(double compile_time_constant);
// Returns v_id
std::string ToString() const;
// Compound operators
ExpressionRef& operator+=(ExpressionRef x);
ExpressionRef& operator-=(ExpressionRef x);
ExpressionRef& operator*=(ExpressionRef x);
ExpressionRef& operator/=(ExpressionRef x);
// The index into the ExpressionGraph data array.
ExpressionId id = kInvalidExpressionId;
static ExpressionRef Create(ExpressionId id);
};
// Arithmetic Operators
ExpressionRef operator-(ExpressionRef x);
ExpressionRef operator+(ExpressionRef x);
ExpressionRef operator+(ExpressionRef x, ExpressionRef y);
ExpressionRef operator-(ExpressionRef x, ExpressionRef y);
ExpressionRef operator*(ExpressionRef x, ExpressionRef y);
ExpressionRef operator/(ExpressionRef x, ExpressionRef y);
// Functions
// TODO: Add all function supported by Jet.
ExpressionRef sin(ExpressionRef x);
// This additonal type is required, so that we can detect invalid conditions
// during compile time. For example, the following should create a compile time
// error:
//
// ExpressionRef a(5);
// CERES_IF(a){ // Error: Invalid conversion
// ...
//
// Following will work:
//
// ExpressionRef a(5), b(7);
// ComparisonExpressionRef c = a < b;
// CERES_IF(c){
// ...
struct ComparisonExpressionRef {
ExpressionId id;
explicit ComparisonExpressionRef(ExpressionRef ref) : id(ref.id) {}
};
ExpressionRef Ternary(ComparisonExpressionRef c,
ExpressionRef a,
ExpressionRef b);
// Comparison operators
ComparisonExpressionRef operator<(ExpressionRef a, ExpressionRef b);
ComparisonExpressionRef operator<=(ExpressionRef a, ExpressionRef b);
ComparisonExpressionRef operator>(ExpressionRef a, ExpressionRef b);
ComparisonExpressionRef operator>=(ExpressionRef a, ExpressionRef b);
ComparisonExpressionRef operator==(ExpressionRef a, ExpressionRef b);
ComparisonExpressionRef operator!=(ExpressionRef a, ExpressionRef b);
// Logical Operators
ComparisonExpressionRef operator&&(ComparisonExpressionRef a,
ComparisonExpressionRef b);
ComparisonExpressionRef operator||(ComparisonExpressionRef a,
ComparisonExpressionRef b);
ComparisonExpressionRef operator!(ComparisonExpressionRef a);
// This struct is used to mark numbers which are constant over
// multiple invocations but can differ between instances.
template <typename T>
struct RuntimeConstant {
using ReturnType = T;
static inline ReturnType Get(double v, const char* name) { return v; }
};
template <typename G, int N>
struct RuntimeConstant<Jet<G, N>> {
using ReturnType = Jet<G, N>;
static inline Jet<G, N> Get(double v, const char* name) {
return Jet<G, N>(v);
}
};
template <int N>
struct RuntimeConstant<Jet<ExpressionRef, N>> {
using ReturnType = Jet<ExpressionRef, N>;
static inline ReturnType Get(double v, const char* name) {
// Note: The scalar value of v will be thrown away, because we don't need it
// during code generation.
(void)v;
return Jet<ExpressionRef, N>(Expression::CreateRuntimeConstant(name));
}
};
template <typename T>
inline typename RuntimeConstant<T>::ReturnType MakeRuntimeConstant(
double v, const char* name) {
return RuntimeConstant<T>::Get(v, name);
}
#define CERES_EXPRESSION_RUNTIME_CONSTANT(_v) \
ceres::internal::MakeRuntimeConstant<T>(_v, #_v)
} // namespace internal
// See jet.h for more info on this type.
template <>
struct ComparisonReturnType<internal::ExpressionRef> {
using type = internal::ComparisonExpressionRef;
};
} // namespace ceres
#endif
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@@ -168,6 +168,20 @@
namespace ceres {
// The return type of a Jet comparison, for example from <, &&, ==.
//
// In the context of traditional Ceres Jet operations, this would
// always be a bool. However, in the autodiff code generation context,
// the return is always an expression, and so a different type must be
// used as a return from comparisons.
//
// In the autodiff codegen context, this function is overloaded so that 'type'
// is one of the autodiff code generation expression types.
template <typename T>
struct ComparisonReturnType {
using type = bool;
};
template <typename T, int N>
struct Jet {
enum { DIMENSION = N };
@@ -353,18 +367,21 @@ inline Jet<T, N> operator/(const Jet<T, N>& f, T s) {
}
// Binary comparison operators for both scalars and jets.
#define CERES_DEFINE_JET_COMPARISON_OPERATOR(op) \
template <typename T, int N> \
inline bool operator op(const Jet<T, N>& f, const Jet<T, N>& g) { \
return f.a op g.a; \
} \
template <typename T, int N> \
inline bool operator op(const T& s, const Jet<T, N>& g) { \
return s op g.a; \
} \
template <typename T, int N> \
inline bool operator op(const Jet<T, N>& f, const T& s) { \
return f.a op s; \
#define CERES_DEFINE_JET_COMPARISON_OPERATOR(op) \
template <typename T, int N> \
inline typename ComparisonReturnType<T>::type operator op( \
const Jet<T, N>& f, const Jet<T, N>& g) { \
return f.a op g.a; \
} \
template <typename T, int N> \
inline typename ComparisonReturnType<T>::type operator op( \
const T& s, const Jet<T, N>& g) { \
return s op g.a; \
} \
template <typename T, int N> \
inline typename ComparisonReturnType<T>::type operator op( \
const Jet<T, N>& f, const T& s) { \
return f.a op s; \
}
CERES_DEFINE_JET_COMPARISON_OPERATOR(<) // NOLINT
CERES_DEFINE_JET_COMPARISON_OPERATOR(<=) // NOLINT
@@ -374,6 +391,26 @@ CERES_DEFINE_JET_COMPARISON_OPERATOR(==) // NOLINT
CERES_DEFINE_JET_COMPARISON_OPERATOR(!=) // NOLINT
#undef CERES_DEFINE_JET_COMPARISON_OPERATOR
// A function equivalent to the ternary ?-operator.
// This function is required, because in the context of code generation a
// comparison returns an expression type which is not convertible to bool.
template <typename T>
inline T Ternary(bool c, T a, T b) {
return c ? a : b;
}
template <typename T, int N>
inline Jet<T, N> Ternary(typename ComparisonReturnType<T>::type c,
const Jet<T, N>& f,
const Jet<T, N>& g) {
Jet<T, N> r;
r.a = Ternary(c, f.a, g.a);
for (int i = 0; i < N; ++i) {
r.v[i] = Ternary(c, f.v[i], g.v[i]);
}
return r;
}
// Pull some functions from namespace std.
//
// This is necessary because we want to use the same name (e.g. 'sqrt') for
+5
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@@ -82,6 +82,9 @@ set(CERES_INTERNAL_SRC
dynamic_sparse_normal_cholesky_solver.cc
evaluator.cc
eigensparse.cc
expression.cc
expression_graph.cc
expression_ref.cc
file.cc
float_suitesparse.cc
float_cxsparse.cc
@@ -433,6 +436,8 @@ if (BUILD_TESTING AND GFLAGS)
ceres_test(dynamic_sparsity)
ceres_test(evaluation_callback)
ceres_test(evaluator)
ceres_test(expression)
ceres_test(expression_graph)
ceres_test(fixed_array)
ceres_test(gradient_checker)
ceres_test(gradient_checking_cost_function)
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@@ -0,0 +1,178 @@
// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
#include "ceres/internal/expression.h"
#include <algorithm>
#include "ceres/internal/expression_graph.h"
#include "glog/logging.h"
namespace ceres {
namespace internal {
static Expression& MakeExpression(ExpressionType type) {
auto pool = GetCurrentExpressionGraph();
CHECK(pool)
<< "The ExpressionGraph has to be created before using Expressions. This "
"is achieved by calling ceres::StartRecordingExpressions.";
return pool->CreateExpression(type);
}
ExpressionId Expression::CreateCompileTimeConstant(double v) {
auto& expr = MakeExpression(ExpressionType::COMPILE_TIME_CONSTANT);
expr.value_ = v;
return expr.id_;
}
ExpressionId Expression::CreateRuntimeConstant(const std::string& name) {
auto& expr = MakeExpression(ExpressionType::RUNTIME_CONSTANT);
expr.name_ = name;
return expr.id_;
}
ExpressionId Expression::CreateParameter(const std::string& name) {
auto& expr = MakeExpression(ExpressionType::PARAMETER);
expr.name_ = name;
return expr.id_;
}
ExpressionId Expression::CreateAssignment(ExpressionId v) {
auto& expr = MakeExpression(ExpressionType::ASSIGNMENT);
expr.arguments_.push_back(v);
return expr.id_;
}
ExpressionId Expression::CreateUnaryArithmetic(ExpressionType type,
ExpressionId v) {
auto& expr = MakeExpression(type);
expr.arguments_.push_back(v);
return expr.id_;
}
ExpressionId Expression::CreateOutputAssignment(ExpressionId v,
const std::string& name) {
auto& expr = MakeExpression(ExpressionType::OUTPUT_ASSIGNMENT);
expr.arguments_.push_back(v);
expr.name_ = name;
return expr.id_;
}
ExpressionId Expression::CreateFunctionCall(
const std::string& name, const std::vector<ExpressionId>& params) {
auto& expr = MakeExpression(ExpressionType::FUNCTION_CALL);
expr.arguments_ = params;
expr.name_ = name;
return expr.id_;
}
ExpressionId Expression::CreateTernary(ExpressionId condition,
ExpressionId if_true,
ExpressionId if_false) {
auto& expr = MakeExpression(ExpressionType::TERNARY);
expr.arguments_.push_back(condition);
expr.arguments_.push_back(if_true);
expr.arguments_.push_back(if_false);
return expr.id_;
}
ExpressionId Expression::CreateBinaryCompare(const std::string& name,
ExpressionId l,
ExpressionId r) {
auto& expr = MakeExpression(ExpressionType::BINARY_COMPARISON);
expr.arguments_.push_back(l);
expr.arguments_.push_back(r);
expr.name_ = name;
return expr.id_;
}
ExpressionId Expression::CreateLogicalNegation(ExpressionId v) {
auto& expr = MakeExpression(ExpressionType::LOGICAL_NEGATION);
expr.arguments_.push_back(v);
return expr.id_;
}
ExpressionId Expression::CreateBinaryArithmetic(ExpressionType type,
ExpressionId l,
ExpressionId r) {
auto& expr = MakeExpression(type);
expr.arguments_.push_back(l);
expr.arguments_.push_back(r);
return expr.id_;
}
Expression::Expression(ExpressionType type, ExpressionId id)
: type_(type), id_(id) {}
bool Expression::IsArithmetic() const {
switch (type_) {
case ExpressionType::PLUS:
case ExpressionType::MULTIPLICATION:
case ExpressionType::DIVISION:
case ExpressionType::MINUS:
case ExpressionType::UNARY_MINUS:
case ExpressionType::UNARY_PLUS:
return true;
default:
return false;
}
}
bool Expression::IsReplaceableBy(const Expression& other) const {
// Check everything except the id.
return (type_ == other.type_ && name_ == other.name_ &&
value_ == other.value_ && arguments_ == other.arguments_);
}
void Expression::Replace(const Expression& other) {
if (other.id_ == id_) {
return;
}
type_ = other.type_;
arguments_ = other.arguments_;
name_ = other.name_;
value_ = other.value_;
}
bool Expression::DirectlyDependsOn(ExpressionId other) const {
return (std::find(arguments_.begin(), arguments_.end(), other) !=
arguments_.end());
}
bool Expression::IsCompileTimeConstantAndEqualTo(double constant) const {
return type_ == ExpressionType::COMPILE_TIME_CONSTANT && value_ == constant;
}
void Expression::MakeNop() {
type_ = ExpressionType::NOP;
arguments_.clear();
}
} // namespace internal
} // namespace ceres
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
#include "ceres/internal/expression_graph.h"
#include "glog/logging.h"
namespace ceres {
namespace internal {
static ExpressionGraph* expression_pool = nullptr;
void StartRecordingExpressions() {
CHECK(expression_pool == nullptr)
<< "Expression recording must be stopped before calling "
"StartRecordingExpressions again.";
expression_pool = new ExpressionGraph;
}
ExpressionGraph StopRecordingExpressions() {
CHECK(expression_pool)
<< "Expression recording hasn't started yet or you tried "
"to stop it twice.";
ExpressionGraph result = std::move(*expression_pool);
delete expression_pool;
expression_pool = nullptr;
return result;
}
ExpressionGraph* GetCurrentExpressionGraph() { return expression_pool; }
Expression& ExpressionGraph::CreateExpression(ExpressionType type) {
auto id = expressions_.size();
Expression expr(type, id);
expressions_.push_back(expr);
return expressions_.back();
}
bool ExpressionGraph::DependsOn(ExpressionId A, ExpressionId B) const {
// Depth first search on the expression graph
// Equivalent Recursive Implementation:
// if (A.DirectlyDependsOn(B)) return true;
// for (auto p : A.params_) {
// if (pool[p.id].DependsOn(B, pool)) return true;
// }
std::vector<ExpressionId> stack = ExpressionForId(A).arguments_;
while (!stack.empty()) {
auto top = stack.back();
stack.pop_back();
if (top == B) {
return true;
}
auto& expr = ExpressionForId(top);
stack.insert(stack.end(), expr.arguments_.begin(), expr.arguments_.end());
}
return false;
}
} // namespace internal
} // namespace ceres
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
//
// Test expression creation and logic.
#include "ceres/internal/expression_graph.h"
#include "ceres/internal/expression_ref.h"
#include "gtest/gtest.h"
namespace ceres {
namespace internal {
TEST(ExpressionGraph, Creation) {
using T = ExpressionRef;
ExpressionGraph graph;
StartRecordingExpressions();
graph = StopRecordingExpressions();
EXPECT_EQ(graph.Size(), 0);
StartRecordingExpressions();
T a(1);
T b(2);
T c = a + b;
graph = StopRecordingExpressions();
EXPECT_EQ(graph.Size(), 3);
}
TEST(ExpressionGraph, Dependencies) {
using T = ExpressionRef;
StartRecordingExpressions();
T unused(6);
T a(2), b(3);
T c = a + b;
T d = c + a;
auto tree = StopRecordingExpressions();
// Recursive dependency check
ASSERT_TRUE(tree.DependsOn(d.id, c.id));
ASSERT_TRUE(tree.DependsOn(d.id, a.id));
ASSERT_TRUE(tree.DependsOn(d.id, b.id));
ASSERT_FALSE(tree.DependsOn(d.id, unused.id));
}
} // namespace internal
} // namespace ceres
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
#include "ceres/internal/expression_ref.h"
#include "assert.h"
#include "ceres/internal/expression.h"
namespace ceres {
namespace internal {
ExpressionRef ExpressionRef::Create(ExpressionId id) {
ExpressionRef ref;
ref.id = id;
return ref;
}
std::string ExpressionRef::ToString() const { return std::to_string(id); }
ExpressionRef::ExpressionRef(double compile_time_constant) {
(*this) = ExpressionRef::Create(
Expression::CreateCompileTimeConstant(compile_time_constant));
}
// Compound operators
ExpressionRef& ExpressionRef::operator+=(ExpressionRef y) {
*this = *this + y;
return *this;
}
ExpressionRef& ExpressionRef::operator-=(ExpressionRef y) {
*this = *this - y;
return *this;
}
ExpressionRef& ExpressionRef::operator*=(ExpressionRef y) {
*this = *this * y;
return *this;
}
ExpressionRef& ExpressionRef::operator/=(ExpressionRef y) {
*this = *this / y;
return *this;
}
// Arith. Operators
ExpressionRef operator-(ExpressionRef x) {
return ExpressionRef::Create(
Expression::CreateUnaryArithmetic(ExpressionType::UNARY_MINUS, x.id));
}
ExpressionRef operator+(ExpressionRef x) {
return ExpressionRef::Create(
Expression::CreateUnaryArithmetic(ExpressionType::UNARY_PLUS, x.id));
}
ExpressionRef operator+(ExpressionRef x, ExpressionRef y) {
return ExpressionRef::Create(
Expression::CreateBinaryArithmetic(ExpressionType::PLUS, x.id, y.id));
}
ExpressionRef operator-(ExpressionRef x, ExpressionRef y) {
return ExpressionRef::Create(
Expression::CreateBinaryArithmetic(ExpressionType::MINUS, x.id, y.id));
}
ExpressionRef operator/(ExpressionRef x, ExpressionRef y) {
return ExpressionRef::Create(
Expression::CreateBinaryArithmetic(ExpressionType::DIVISION, x.id, y.id));
}
ExpressionRef operator*(ExpressionRef x, ExpressionRef y) {
return ExpressionRef::Create(Expression::CreateBinaryArithmetic(
ExpressionType::MULTIPLICATION, x.id, y.id));
}
// Functions
ExpressionRef sin(ExpressionRef x) {
return ExpressionRef::Create(Expression::CreateFunctionCall("sin", {x.id}));
}
ExpressionRef Ternary(ComparisonExpressionRef c,
ExpressionRef a,
ExpressionRef b) {
return ExpressionRef::Create(Expression::CreateTernary(c.id, a.id, b.id));
}
#define CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(op) \
ComparisonExpressionRef operator op(ExpressionRef a, ExpressionRef b) { \
return ComparisonExpressionRef(ExpressionRef::Create( \
Expression::CreateBinaryCompare(#op, a.id, b.id))); \
}
#define CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(op) \
ComparisonExpressionRef operator op(ComparisonExpressionRef a, \
ComparisonExpressionRef b) { \
return ComparisonExpressionRef(ExpressionRef::Create( \
Expression::CreateBinaryCompare(#op, a.id, b.id))); \
}
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(<)
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(<=)
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(>)
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(>=)
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(==)
CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(!=)
CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(&&)
CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(||)
#undef CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR
#undef CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR
ComparisonExpressionRef operator!(ComparisonExpressionRef a) {
return ComparisonExpressionRef(
ExpressionRef::Create(Expression::CreateLogicalNegation(a.id)));
}
} // namespace internal
} // namespace ceres
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// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2019 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: darius.rueckert@fau.de (Darius Rueckert)
//
#include "ceres/internal/expression_graph.h"
#include "ceres/internal/expression_ref.h"
#include "gtest/gtest.h"
namespace ceres {
namespace internal {
TEST(Expression, IsArithmetic) {
using T = ExpressionRef;
StartRecordingExpressions();
T a(2), b(3);
T c = a + b;
T d = c + a;
auto graph = StopRecordingExpressions();
ASSERT_FALSE(graph.ExpressionForId(a.id).IsArithmetic());
ASSERT_FALSE(graph.ExpressionForId(b.id).IsArithmetic());
ASSERT_TRUE(graph.ExpressionForId(c.id).IsArithmetic());
ASSERT_TRUE(graph.ExpressionForId(d.id).IsArithmetic());
}
TEST(Expression, IsCompileTimeConstantAndEqualTo) {
using T = ExpressionRef;
StartRecordingExpressions();
T a(2), b(3);
T c = a + b;
auto graph = StopRecordingExpressions();
ASSERT_TRUE(graph.ExpressionForId(a.id).IsCompileTimeConstantAndEqualTo(2));
ASSERT_FALSE(graph.ExpressionForId(a.id).IsCompileTimeConstantAndEqualTo(0));
ASSERT_TRUE(graph.ExpressionForId(b.id).IsCompileTimeConstantAndEqualTo(3));
ASSERT_FALSE(graph.ExpressionForId(c.id).IsCompileTimeConstantAndEqualTo(0));
}
TEST(Expression, IsReplaceableBy) {
using T = ExpressionRef;
StartRecordingExpressions();
// a2 should be replaceable by a
T a(2), b(3), a2(2);
// two redundant expressions
// -> d should be replaceable by c
T c = a + b;
T d = a + b;
auto graph = StopRecordingExpressions();
ASSERT_TRUE(graph.ExpressionForId(a2.id).IsReplaceableBy(
graph.ExpressionForId(a.id)));
ASSERT_TRUE(
graph.ExpressionForId(d.id).IsReplaceableBy(graph.ExpressionForId(c.id)));
ASSERT_FALSE(graph.ExpressionForId(d.id).IsReplaceableBy(
graph.ExpressionForId(a2.id)));
}
TEST(Expression, DirectlyDependsOn) {
using T = ExpressionRef;
StartRecordingExpressions();
T unused(6);
T a(2), b(3);
T c = a + b;
T d = c + a;
auto graph = StopRecordingExpressions();
ASSERT_FALSE(graph.ExpressionForId(a.id).DirectlyDependsOn(unused.id));
ASSERT_TRUE(graph.ExpressionForId(c.id).DirectlyDependsOn(a.id));
ASSERT_TRUE(graph.ExpressionForId(c.id).DirectlyDependsOn(b.id));
ASSERT_TRUE(graph.ExpressionForId(d.id).DirectlyDependsOn(a.id));
ASSERT_FALSE(graph.ExpressionForId(d.id).DirectlyDependsOn(b.id));
ASSERT_TRUE(graph.ExpressionForId(d.id).DirectlyDependsOn(c.id));
}
// Todo: remaining functions of Expression
} // namespace internal
} // namespace ceres