| // Ceres Solver - A fast non-linear least squares minimizer | |
| // Copyright 2020 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 | |
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| // 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_CODEGEN_INTERNAL_ELIMINATE_NOPS_H_ | |
| #define CERES_PUBLIC_CODEGEN_INTERNAL_ELIMINATE_NOPS_H_ | |
| #include "ceres/codegen/internal/expression_graph.h" | |
| #include "ceres/codegen/internal/optimization_pass_summary.h" | |
| namespace ceres { | |
| namespace internal { | |
| // [OptimizationPass] NOP Cleanup | |
| // | |
| // Short Description: | |
| // Removes all expression with type==ExpressionType::NOP. | |
| // | |
| // Description: | |
| // Removing an expression not at the end requires reindexing of all later | |
| // expressions. Therefore, other optimization passes replace expression with | |
| // NOP instead of removing them. This optimization pass removes all NOPs back | |
| // to front. | |
| // The returned value is equal to the number of removed NOPs. | |
| // | |
| // Example: | |
| // v_0 = 1; | |
| // // NOP | |
| // v_2 = 2; | |
| // v_3 = v_0 + v_2 | |
| // Transforms to: | |
| // v_0 = 1; | |
| // v_1 = 2; | |
| // v_2 = v_0 + v_1; | |
| OptimizationPassSummary EliminateNops(ExpressionGraph* graph); | |
| } // namespace internal | |
| } // namespace ceres | |
| #endif // CERES_PUBLIC_CODEGEN_INTERNAL_ELIMINATE_NOPS_H_ |