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Add LP format reader; accept .lp wherever .mps is accepted #1120

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cab0b59
refactor(mps_parser): extract finalize_problem into a shared helper
mlubin Apr 17, 2026
fee3214
feat(mps_parser): add LP format parser
mlubin Apr 17, 2026
892e317
feat(cuopt): accept LP files wherever MPS files are accepted
mlubin Apr 17, 2026
daa05cd
docs: document LP file support
mlubin Apr 17, 2026
db2dd95
fix for failing tests
mlubin Apr 20, 2026
c8194c1
test(mps_parser): consolidate LP and MPS parser tests
mlubin Apr 20, 2026
56dabd8
feat(mps_parser): broaden LP parser syntax and tighten bound/quadrati…
mlubin Apr 20, 2026
e48dcfb
feat(mps_parser): reject Lazy Constraints LP sections
mlubin Apr 21, 2026
4023242
docs(mps_parser): drop Gurobi-specific LP dialect references
mlubin Apr 21, 2026
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24 changes: 14 additions & 10 deletions cpp/cuopt_cli.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -38,13 +38,13 @@ static char cuda_module_loading_env[] = "CUDA_MODULE_LOADING=EAGER";
* @brief Command line interface for solving Linear Programming (LP) and Mixed Integer Programming
* (MIP) problems using cuOpt
*
* This CLI provides a simple interface to solve LP/MIP problems using cuOpt. It accepts MPS format
* input files and various solver parameters.
* This CLI provides a simple interface to solve LP/MIP problems using cuOpt. It accepts MPS or LP
* format input files (dispatched automatically by extension) and various solver parameters.
*
* Usage:
* ```
* cuopt_cli <mps_file_path> [OPTIONS]
* cuopt_cli [OPTIONS] <mps_file_path>
* cuopt_cli <input_file_path> [OPTIONS]
* cuopt_cli [OPTIONS] <input_file_path>
* ```
*
* Required arguments:
Expand Down Expand Up @@ -84,7 +84,9 @@ inline cuopt::init_logger_t dummy_logger(

/**
* @brief Run a single file
* @param file_path Path to the MPS format input file containing the optimization problem
* @param file_path Path to the input file in MPS or LP format. Dispatched by
* extension: a ".lp" suffix routes to the LP parser; anything
* else (.mps, .mps.gz, .mps.bz2, or extensionless) to MPS.
* @param initial_solution_file Path to initial solution file in SOL format
* @param settings Merged solver settings (config file loaded in main, then CLI overrides applied)
*/
Expand All @@ -98,22 +100,21 @@ int run_single_file(const std::string& file_path,

std::string base_filename = file_path.substr(file_path.find_last_of("/\\") + 1);

constexpr bool input_mps_strict = false;
cuopt::mps_parser::mps_data_model_t<int, double> mps_data_model;
bool parsing_failed = false;
auto timer = cuopt::timer_t(settings.get_parameter<double>(CUOPT_TIME_LIMIT));
{
CUOPT_LOG_INFO("Reading file %s", base_filename.c_str());
try {
mps_data_model = cuopt::mps_parser::parse_mps<int, double>(file_path, input_mps_strict);
mps_data_model = cuopt::mps_parser::parse_optimization_file<int, double>(file_path);
} catch (const std::logic_error& e) {
CUOPT_LOG_ERROR("MPS parser execption: %s", e.what());
CUOPT_LOG_ERROR("Parser exception: %s", e.what());
parsing_failed = true;
}
}
if (parsing_failed) {
auto log = dummy_logger(settings);
CUOPT_LOG_ERROR("Parsing MPS failed. Exiting!");
CUOPT_LOG_ERROR("Parsing input file failed. Exiting!");
return -1;
}
CUOPT_LOG_INFO("Read file %s in %.2f seconds", base_filename.c_str(), timer.elapsed_time());
Expand Down Expand Up @@ -279,7 +280,10 @@ int main(int argc, char* argv[])
argparse::ArgumentParser program("cuopt_cli", version_string);

// Define all arguments with appropriate defaults and help messages
program.add_argument("filename").help("input mps file").nargs(1).required();
program.add_argument("filename")
.help("input MPS or LP file (dispatched by .lp / .mps extension)")
.nargs(1)
.required();

// FIXME: use a standard format for initial solution file
program.add_argument("--initial-solution")
Expand Down
10 changes: 7 additions & 3 deletions cpp/include/cuopt/linear_programming/cuopt_c.h
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Expand Up @@ -100,12 +100,16 @@ cuopt_int_t cuOptGetVersion(cuopt_int_t* version_major,
cuopt_int_t* version_patch);

/**
* @brief Read an optimization problem from an MPS file.
* @brief Read an optimization problem from an MPS or LP file.
*
* @param[in] filename - The path to the MPS file.
* The file format is dispatched on the extension: a case-insensitive ".lp"
* suffix is parsed as LP format; everything else (including ".mps",
* ".mps.gz", ".mps.bz2", or no extension) is parsed as MPS.
*
* @param[in] filename - The path to the MPS or LP file.
*
* @param[out] problem_ptr - A pointer to a cuOptOptimizationProblem. On output
* the problem will be created and initialized with the data from the MPS file
* the problem will be created and initialized with the data from the input file.
*
* @return A status code indicating success or failure.
*/
Expand Down
1 change: 1 addition & 0 deletions cpp/libmps_parser/CMakeLists.txt
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Expand Up @@ -71,6 +71,7 @@ add_library(mps_parser SHARED
src/data_model_view.cpp
src/mps_data_model.cpp
src/mps_parser.cpp
src/lp_parser.cpp
src/mps_writer.cpp
src/parser.cpp
src/writer.cpp
Expand Down
36 changes: 36 additions & 0 deletions cpp/libmps_parser/include/mps_parser/lp_parser.hpp
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@@ -0,0 +1,36 @@
/* clang-format off */
/*
* SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*/
/* clang-format on */

#pragma once

#include <mps_parser/mps_data_model.hpp>

#include <string>

namespace cuopt::mps_parser {

/**
* @brief Reads a linear, mixed-integer, or quadratic optimization problem from
* a file in LP format.
*
* The LP format is a human-readable alternative to MPS format. This parser
* supports the conventional LP dialect implemented by most commercial
* optimization solvers (not the lpsolve variant, which has a different
* syntax).
*
* Scope: LP, MIP, and QP problems are supported. SOS constraints, PWL
* objectives, semi-continuous variables, general constraints, and user cuts
* cause a ValidationError when encountered.
*
* @param[in] lp_file_path Path to the LP file.
* @return mps_data_model_t A fully formed LP/MIP/QP problem representing the
* given file.
*/
template <typename i_t, typename f_t>
mps_data_model_t<i_t, f_t> parse_lp(const std::string& lp_file_path);

} // namespace cuopt::mps_parser
36 changes: 35 additions & 1 deletion cpp/libmps_parser/include/mps_parser/parser.hpp
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@@ -1,14 +1,18 @@
/* clang-format off */
/*
* SPDX-FileCopyrightText: Copyright (c) 2023-2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*/
/* clang-format on */

#pragma once

#include <mps_parser/lp_parser.hpp>
#include <mps_parser/mps_data_model.hpp>

#include <string>
#include <string_view>

namespace cuopt::mps_parser {

/**
Expand All @@ -35,4 +39,34 @@ template <typename i_t, typename f_t>
mps_data_model_t<i_t, f_t> parse_mps(const std::string& mps_file_path,
bool fixed_mps_format = false);

/**
* @brief Reads an optimization problem from a file, dispatching on the file
* extension.
*
* Case-insensitive `.lp` suffix routes to parse_lp(). Everything else —
* including `.mps`, `.mps.gz`, `.mps.bz2`, and extensionless files — routes
* to parse_mps() (with free-format parsing). This is the entry point of
* choice for user-facing tools (CLI, C API) that want both formats to
* "just work" without an explicit format flag.
*
* @param[in] path Path to the input file.
* @return mps_data_model_t The parsed problem.
*/
template <typename i_t, typename f_t>
inline mps_data_model_t<i_t, f_t> parse_optimization_file(const std::string& path)
{
constexpr std::string_view lp_suffix = ".lp";
auto ends_with_ci = [](std::string_view s, std::string_view suffix) {
if (s.size() < suffix.size()) return false;
for (size_t i = 0; i < suffix.size(); ++i) {
char a = s[s.size() - suffix.size() + i];
if (a >= 'A' && a <= 'Z') a = static_cast<char>(a - 'A' + 'a');
if (a != suffix[i]) return false;
}
return true;
};
if (ends_with_ci(path, lp_suffix)) return parse_lp<i_t, f_t>(path);
return parse_mps<i_t, f_t>(path);
}

} // namespace cuopt::mps_parser
5 changes: 4 additions & 1 deletion cpp/libmps_parser/include/mps_parser/utilities/cython_mps_parser.hpp
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@@ -1,6 +1,6 @@
/* clang-format off */
/*
* SPDX-FileCopyrightText: Copyright (c) 2023-2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*/
/* clang-format on */
Expand All @@ -17,5 +17,8 @@ namespace cython {
std::unique_ptr<cuopt::mps_parser::mps_data_model_t<int, double>> call_parse_mps(
const std::string& mps_file_path, bool fixed_mps_format);

std::unique_ptr<cuopt::mps_parser::mps_data_model_t<int, double>> call_parse_lp(
const std::string& lp_file_path);

} // namespace cython
} // namespace cuopt
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