blob: 52b7e0ba95e63875d316f619dfbfda74b9ae09cd [file] [log] [blame]
// 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/codegen/internal/expression_ref.h"
#include "ceres/codegen/internal/expression_graph.h"
#include "glog/logging.h"
namespace ceres {
namespace internal {
ExpressionRef AddExpressionToGraph(const Expression& expression) {
ExpressionGraph* graph = GetCurrentExpressionGraph();
CHECK(graph)
<< "The ExpressionGraph has to be created before using Expressions. This "
"is achieved by calling ceres::StartRecordingExpressions.";
return ExpressionRef::Create(graph->InsertBack(expression));
}
ExpressionRef ExpressionRef::Create(ExpressionId id) {
ExpressionRef ref;
ref.id = id;
return ref;
}
ExpressionRef::ExpressionRef(double compile_time_constant) {
id = AddExpressionToGraph(
Expression::CreateCompileTimeConstant(compile_time_constant))
.id;
}
ExpressionRef::ExpressionRef(const ExpressionRef& other) { *this = other; }
ExpressionRef& ExpressionRef::operator=(const ExpressionRef& other) {
// Assigning an uninitialized variable to another variable is an error.
CHECK(other.IsInitialized()) << "Uninitialized Assignment.";
if (IsInitialized()) {
// Create assignment from other -> this
AddExpressionToGraph(Expression::CreateAssignment(this->id, other.id));
} else {
// Create a new variable and
// Create assignment from other -> this
// Passing kInvalidExpressionId to CreateAssignment generates a new
// variable name which we store in the id.
id = AddExpressionToGraph(
Expression::CreateAssignment(kInvalidExpressionId, other.id))
.id;
}
return *this;
}
ExpressionRef::ExpressionRef(ExpressionRef&& other) {
*this = std::move(other);
}
ExpressionRef& ExpressionRef::operator=(ExpressionRef&& other) {
// Assigning an uninitialized variable to another variable is an error.
CHECK(other.IsInitialized()) << "Uninitialized Assignment.";
if (IsInitialized()) {
// Create assignment from other -> this
AddExpressionToGraph(Expression::CreateAssignment(id, other.id));
} else {
// Special case: 'this' is uninitialized and other is an rvalue.
// -> Implement copy elision by only setting the reference
// This reduces the number of generated expressions roughly by a factor
// of 2. For example, in the following statement:
// T c = a + b;
// The result of 'a + b' is an rvalue reference to ExpressionRef.
// Therefore, the move constructor of 'c' is called. Since 'c' is also
// uninitialized, this branch here is taken and the copy is removed. After
// this function 'c' will just point to the temporary created by the 'a +
// b' expression. This is valid, because we don't have any scoping
// information and therefore assume global scope for all temporary
// variables. The generated code for the single statement above, is:
// v_2 = v_0 + v_1; // With c.id = 2
// Without this move constructor the following two lines would be
// generated:
// v_2 = v_0 + v_1;
// v_3 = v_2; // With c.id = 3
id = other.id;
}
other.id = kInvalidExpressionId;
return *this;
}
// Compound operators
ExpressionRef& ExpressionRef::operator+=(const ExpressionRef& x) {
*this = *this + x;
return *this;
}
ExpressionRef& ExpressionRef::operator-=(const ExpressionRef& x) {
*this = *this - x;
return *this;
}
ExpressionRef& ExpressionRef::operator*=(const ExpressionRef& x) {
*this = *this * x;
return *this;
}
ExpressionRef& ExpressionRef::operator/=(const ExpressionRef& x) {
*this = *this / x;
return *this;
}
// Arith. Operators
ExpressionRef operator-(const ExpressionRef& x) {
return AddExpressionToGraph(Expression::CreateUnaryArithmetic("-", x.id));
}
ExpressionRef operator+(const ExpressionRef& x) {
return AddExpressionToGraph(Expression::CreateUnaryArithmetic("+", x.id));
}
ExpressionRef operator+(const ExpressionRef& x, const ExpressionRef& y) {
return AddExpressionToGraph(
Expression::CreateBinaryArithmetic("+", x.id, y.id));
}
ExpressionRef operator-(const ExpressionRef& x, const ExpressionRef& y) {
return AddExpressionToGraph(
Expression::CreateBinaryArithmetic("-", x.id, y.id));
}
ExpressionRef operator/(const ExpressionRef& x, const ExpressionRef& y) {
return AddExpressionToGraph(
Expression::CreateBinaryArithmetic("/", x.id, y.id));
}
ExpressionRef operator*(const ExpressionRef& x, const ExpressionRef& y) {
return AddExpressionToGraph(
Expression::CreateBinaryArithmetic("*", x.id, y.id));
}
ExpressionRef Ternary(const ComparisonExpressionRef& c,
const ExpressionRef& x,
const ExpressionRef& y) {
return AddExpressionToGraph(
Expression::CreateScalarFunctionCall("Ternary", {c.id, x.id, y.id}));
}
#define CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR(op) \
ComparisonExpressionRef operator op(const ExpressionRef& x, \
const ExpressionRef& y) { \
return ComparisonExpressionRef(AddExpressionToGraph( \
Expression::CreateBinaryCompare(#op, x.id, y.id))); \
}
#define CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(op) \
ComparisonExpressionRef operator op(const ComparisonExpressionRef& x, \
const ComparisonExpressionRef& y) { \
return ComparisonExpressionRef(AddExpressionToGraph( \
Expression::CreateBinaryCompare(#op, x.id, y.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(||)
CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(&)
CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR(|)
#undef CERES_DEFINE_EXPRESSION_COMPARISON_OPERATOR
#undef CERES_DEFINE_EXPRESSION_LOGICAL_OPERATOR
ComparisonExpressionRef operator!(const ComparisonExpressionRef& x) {
return ComparisonExpressionRef(
AddExpressionToGraph(Expression::CreateLogicalNegation(x.id)));
}
} // namespace internal
} // namespace ceres