Fix occasional incorrect solution bound on maximization problems#76
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aliceb-nv wants to merge 3 commits intobranch-25.08from
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Fix occasional incorrect solution bound on maximization problems#76aliceb-nv wants to merge 3 commits intobranch-25.08from
aliceb-nv wants to merge 3 commits intobranch-25.08from
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<!-- Thank you for contributing to cuOpt :) Here are some guidelines to help the review process go smoothly. 1. Please write a description in this text box of the changes that are being made. 2. Please ensure that you have written units tests for the changes made/features added. 3. If you are closing an issue please use one of the automatic closing words as noted here: https://help.github.com/articles/closing-issues-using-keywords/ 4. If your pull request is not ready for review but you want to make use of the continuous integration testing facilities please label it with `[WIP]`. 5. If your pull request is ready to be reviewed without requiring additional work on top of it, then remove the `[WIP]` label (if present) and replace it with `[REVIEW]`. If assistance is required to complete the functionality, for example when the C/C++ code of a feature is complete but Python bindings are still required, then add the label `[HELP-REQ]` so that others can triage and assist. The additional changes then can be implemented on top of the same PR. If the assistance is done by members of the rapidsAI team, then no additional actions are required by the creator of the original PR for this, otherwise the original author of the PR needs to give permission to the person(s) assisting to commit to their personal fork of the project. If that doesn't happen then a new PR based on the code of the original PR can be opened by the person assisting, which then will be the PR that will be merged. 6. Once all work has been done and review has taken place please do not add features or make changes out of the scope of those requested by the reviewer (doing this just add delays as already reviewed code ends up having to be re-reviewed/it is hard to tell what is new etc!). Further, please do not rebase your branch on main/force push/rewrite history, doing any of these causes the context of any comments made by reviewers to be lost. If conflicts occur against main they should be resolved by merging main into the branch used for making the pull request. Many thanks in advance for your cooperation! --> During the PDLP LP relaxation phase, the solution bound was incorrectly converted to a user objective value twice, yielding an incorrect sign on maximizations problems. This only occurs before B&B updates the bound further, which explains why this bug only occurs in specific scenarios (short runs, large problems). This also fixes optimality not being reported on simple maximizations problems. closes #76
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…DIA#83) <!-- Thank you for contributing to cuOpt :) Here are some guidelines to help the review process go smoothly. 1. Please write a description in this text box of the changes that are being made. 2. Please ensure that you have written units tests for the changes made/features added. 3. If you are closing an issue please use one of the automatic closing words as noted here: https://help.github.com/articles/closing-issues-using-keywords/ 4. If your pull request is not ready for review but you want to make use of the continuous integration testing facilities please label it with `[WIP]`. 5. If your pull request is ready to be reviewed without requiring additional work on top of it, then remove the `[WIP]` label (if present) and replace it with `[REVIEW]`. If assistance is required to complete the functionality, for example when the C/C++ code of a feature is complete but Python bindings are still required, then add the label `[HELP-REQ]` so that others can triage and assist. The additional changes then can be implemented on top of the same PR. If the assistance is done by members of the rapidsAI team, then no additional actions are required by the creator of the original PR for this, otherwise the original author of the PR needs to give permission to the person(s) assisting to commit to their personal fork of the project. If that doesn't happen then a new PR based on the code of the original PR can be opened by the person assisting, which then will be the PR that will be merged. 6. Once all work has been done and review has taken place please do not add features or make changes out of the scope of those requested by the reviewer (doing this just add delays as already reviewed code ends up having to be re-reviewed/it is hard to tell what is new etc!). Further, please do not rebase your branch on main/force push/rewrite history, doing any of these causes the context of any comments made by reviewers to be lost. If conflicts occur against main they should be resolved by merging main into the branch used for making the pull request. Many thanks in advance for your cooperation! --> During the PDLP LP relaxation phase, the solution bound was incorrectly converted to a user objective value twice, yielding an incorrect sign on maximizations problems. This only occurs before B&B updates the bound further, which explains why this bug only occurs in specific scenarios (short runs, large problems). This also fixes optimality not being reported on simple maximizations problems. closes NVIDIA#76
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During the PDLP LP relaxation phase, the solution bound was incorrectly converted to a user objective value twice, yielding an incorrect sign on maximizations problems. This only occurs before B&B updates the bound further, which explains why this bug only occurs in specific scenarios (short runs, large problems).
This also fixes optimality not being reported on simple maximizations problems.