xref: /llvm-project/mlir/lib/Bindings/Python/ExecutionEngineModule.cpp (revision 784a5bccfd2bffd698be18ad13cdcd2162c981e2)
1 //===- ExecutionEngineModule.cpp - Python module for execution engine -----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "mlir-c/ExecutionEngine.h"
10 #include "mlir/Bindings/Python/PybindAdaptors.h"
11 
12 namespace py = pybind11;
13 using namespace mlir;
14 using namespace mlir::python;
15 
16 namespace {
17 
18 /// Owning Wrapper around an ExecutionEngine.
19 class PyExecutionEngine {
20 public:
21   PyExecutionEngine(MlirExecutionEngine executionEngine)
22       : executionEngine(executionEngine) {}
23   PyExecutionEngine(PyExecutionEngine &&other)
24       : executionEngine(other.executionEngine) {
25     other.executionEngine.ptr = nullptr;
26   }
27   ~PyExecutionEngine() {
28     if (!mlirExecutionEngineIsNull(executionEngine))
29       mlirExecutionEngineDestroy(executionEngine);
30   }
31   MlirExecutionEngine get() { return executionEngine; }
32 
33   void release() {
34     executionEngine.ptr = nullptr;
35     referencedObjects.clear();
36   }
37   pybind11::object getCapsule() {
38     return py::reinterpret_steal<py::object>(
39         mlirPythonExecutionEngineToCapsule(get()));
40   }
41 
42   // Add an object to the list of referenced objects whose lifetime must exceed
43   // those of the ExecutionEngine.
44   void addReferencedObject(const pybind11::object &obj) {
45     referencedObjects.push_back(obj);
46   }
47 
48   static pybind11::object createFromCapsule(pybind11::object capsule) {
49     MlirExecutionEngine rawPm =
50         mlirPythonCapsuleToExecutionEngine(capsule.ptr());
51     if (mlirExecutionEngineIsNull(rawPm))
52       throw py::error_already_set();
53     return py::cast(PyExecutionEngine(rawPm), py::return_value_policy::move);
54   }
55 
56 private:
57   MlirExecutionEngine executionEngine;
58   // We support Python ctypes closures as callbacks. Keep a list of the objects
59   // so that they don't get garbage collected. (The ExecutionEngine itself
60   // just holds raw pointers with no lifetime semantics).
61   std::vector<py::object> referencedObjects;
62 };
63 
64 } // namespace
65 
66 /// Create the `mlir.execution_engine` module here.
67 PYBIND11_MODULE(_mlirExecutionEngine, m) {
68   m.doc() = "MLIR Execution Engine";
69 
70   //----------------------------------------------------------------------------
71   // Mapping of the top-level PassManager
72   //----------------------------------------------------------------------------
73   py::class_<PyExecutionEngine>(m, "ExecutionEngine", py::module_local())
74       .def(py::init<>([](MlirModule module, int optLevel,
75                          const std::vector<std::string> &sharedLibPaths) {
76              llvm::SmallVector<MlirStringRef, 4> libPaths;
77              for (const std::string &path : sharedLibPaths)
78                libPaths.push_back({path.c_str(), path.length()});
79              MlirExecutionEngine executionEngine = mlirExecutionEngineCreate(
80                  module, optLevel, libPaths.size(), libPaths.data());
81              if (mlirExecutionEngineIsNull(executionEngine))
82                throw std::runtime_error(
83                    "Failure while creating the ExecutionEngine.");
84              return new PyExecutionEngine(executionEngine);
85            }),
86            py::arg("module"), py::arg("opt_level") = 2,
87            py::arg("shared_libs") = py::list(),
88            "Create a new ExecutionEngine instance for the given Module. The "
89            "module must contain only dialects that can be translated to LLVM. "
90            "Perform transformations and code generation at the optimization "
91            "level `opt_level` if specified, or otherwise at the default "
92            "level of two (-O2). Load a list of libraries specified in "
93            "`shared_libs`.")
94       .def_property_readonly(MLIR_PYTHON_CAPI_PTR_ATTR,
95                              &PyExecutionEngine::getCapsule)
96       .def("_testing_release", &PyExecutionEngine::release,
97            "Releases (leaks) the backing ExecutionEngine (for testing purpose)")
98       .def(MLIR_PYTHON_CAPI_FACTORY_ATTR, &PyExecutionEngine::createFromCapsule)
99       .def(
100           "raw_lookup",
101           [](PyExecutionEngine &executionEngine, const std::string &func) {
102             auto *res = mlirExecutionEngineLookupPacked(
103                 executionEngine.get(),
104                 mlirStringRefCreate(func.c_str(), func.size()));
105             return reinterpret_cast<uintptr_t>(res);
106           },
107           py::arg("func_name"),
108           "Lookup function `func` in the ExecutionEngine.")
109       .def(
110           "raw_register_runtime",
111           [](PyExecutionEngine &executionEngine, const std::string &name,
112              py::object callbackObj) {
113             executionEngine.addReferencedObject(callbackObj);
114             uintptr_t rawSym =
115                 py::cast<uintptr_t>(py::getattr(callbackObj, "value"));
116             mlirExecutionEngineRegisterSymbol(
117                 executionEngine.get(),
118                 mlirStringRefCreate(name.c_str(), name.size()),
119                 reinterpret_cast<void *>(rawSym));
120           },
121           py::arg("name"), py::arg("callback"),
122           "Register `callback` as the runtime symbol `name`.")
123       .def(
124           "dump_to_object_file",
125           [](PyExecutionEngine &executionEngine, const std::string &fileName) {
126             mlirExecutionEngineDumpToObjectFile(
127                 executionEngine.get(),
128                 mlirStringRefCreate(fileName.c_str(), fileName.size()));
129           },
130           py::arg("file_name"), "Dump ExecutionEngine to an object file.");
131 }
132