1 //===- jit-runner.cpp - MLIR CPU Execution Driver Library -----------------===//
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 // This is a library that provides a shared implementation for command line
10 // utilities that execute an MLIR file on the CPU by translating MLIR to LLVM
11 // IR before JIT-compiling and executing the latter.
12 //
13 // The translation can be customized by providing an MLIR to MLIR
14 // transformation.
15 //===----------------------------------------------------------------------===//
16 
17 #include "mlir/ExecutionEngine/JitRunner.h"
18 
19 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
20 #include "mlir/ExecutionEngine/ExecutionEngine.h"
21 #include "mlir/ExecutionEngine/OptUtils.h"
22 #include "mlir/IR/BuiltinTypes.h"
23 #include "mlir/IR/MLIRContext.h"
24 #include "mlir/Parser.h"
25 #include "mlir/Support/FileUtilities.h"
26 
27 #include "llvm/ADT/STLExtras.h"
28 #include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h"
29 #include "llvm/IR/IRBuilder.h"
30 #include "llvm/IR/LLVMContext.h"
31 #include "llvm/IR/LegacyPassNameParser.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/FileUtilities.h"
34 #include "llvm/Support/SourceMgr.h"
35 #include "llvm/Support/StringSaver.h"
36 #include "llvm/Support/ToolOutputFile.h"
37 #include <cstdint>
38 #include <numeric>
39 
40 using namespace mlir;
41 using llvm::Error;
42 
43 namespace {
44 /// This options struct prevents the need for global static initializers, and
45 /// is only initialized if the JITRunner is invoked.
46 struct Options {
47   llvm::cl::opt<std::string> inputFilename{llvm::cl::Positional,
48                                            llvm::cl::desc("<input file>"),
49                                            llvm::cl::init("-")};
50   llvm::cl::opt<std::string> mainFuncName{
51       "e", llvm::cl::desc("The function to be called"),
52       llvm::cl::value_desc("<function name>"), llvm::cl::init("main")};
53   llvm::cl::opt<std::string> mainFuncType{
54       "entry-point-result",
55       llvm::cl::desc("Textual description of the function type to be called"),
56       llvm::cl::value_desc("f32 | i32 | i64 | void"), llvm::cl::init("f32")};
57 
58   llvm::cl::OptionCategory optFlags{"opt-like flags"};
59 
60   // CLI list of pass information
61   llvm::cl::list<const llvm::PassInfo *, bool, llvm::PassNameParser> llvmPasses{
62       llvm::cl::desc("LLVM optimizing passes to run"), llvm::cl::cat(optFlags)};
63 
64   // CLI variables for -On options.
65   llvm::cl::opt<bool> optO0{"O0",
66                             llvm::cl::desc("Run opt passes and codegen at O0"),
67                             llvm::cl::cat(optFlags)};
68   llvm::cl::opt<bool> optO1{"O1",
69                             llvm::cl::desc("Run opt passes and codegen at O1"),
70                             llvm::cl::cat(optFlags)};
71   llvm::cl::opt<bool> optO2{"O2",
72                             llvm::cl::desc("Run opt passes and codegen at O2"),
73                             llvm::cl::cat(optFlags)};
74   llvm::cl::opt<bool> optO3{"O3",
75                             llvm::cl::desc("Run opt passes and codegen at O3"),
76                             llvm::cl::cat(optFlags)};
77 
78   llvm::cl::OptionCategory clOptionsCategory{"linking options"};
79   llvm::cl::list<std::string> clSharedLibs{
80       "shared-libs", llvm::cl::desc("Libraries to link dynamically"),
81       llvm::cl::ZeroOrMore, llvm::cl::MiscFlags::CommaSeparated,
82       llvm::cl::cat(clOptionsCategory)};
83 
84   /// CLI variables for debugging.
85   llvm::cl::opt<bool> dumpObjectFile{
86       "dump-object-file",
87       llvm::cl::desc("Dump JITted-compiled object to file specified with "
88                      "-object-filename (<input file>.o by default).")};
89 
90   llvm::cl::opt<std::string> objectFilename{
91       "object-filename",
92       llvm::cl::desc("Dump JITted-compiled object to file <input file>.o")};
93 };
94 
95 struct CompileAndExecuteConfig {
96   /// LLVM module transformer that is passed to ExecutionEngine.
97   llvm::function_ref<llvm::Error(llvm::Module *)> transformer;
98 
99   /// A custom function that is passed to ExecutionEngine. It processes MLIR
100   /// module and creates LLVM IR module.
101   llvm::function_ref<std::unique_ptr<llvm::Module>(ModuleOp,
102                                                    llvm::LLVMContext &)>
103       llvmModuleBuilder;
104 
105   /// A custom function that is passed to ExecutinEngine to register symbols at
106   /// runtime.
107   llvm::function_ref<llvm::orc::SymbolMap(llvm::orc::MangleAndInterner)>
108       runtimeSymbolMap;
109 };
110 
111 } // end anonymous namespace
112 
113 static OwningModuleRef parseMLIRInput(StringRef inputFilename,
114                                       MLIRContext *context) {
115   // Set up the input file.
116   std::string errorMessage;
117   auto file = openInputFile(inputFilename, &errorMessage);
118   if (!file) {
119     llvm::errs() << errorMessage << "\n";
120     return nullptr;
121   }
122 
123   llvm::SourceMgr sourceMgr;
124   sourceMgr.AddNewSourceBuffer(std::move(file), llvm::SMLoc());
125   return OwningModuleRef(parseSourceFile(sourceMgr, context));
126 }
127 
128 static inline Error make_string_error(const Twine &message) {
129   return llvm::make_error<llvm::StringError>(message.str(),
130                                              llvm::inconvertibleErrorCode());
131 }
132 
133 static Optional<unsigned> getCommandLineOptLevel(Options &options) {
134   Optional<unsigned> optLevel;
135   SmallVector<std::reference_wrapper<llvm::cl::opt<bool>>, 4> optFlags{
136       options.optO0, options.optO1, options.optO2, options.optO3};
137 
138   // Determine if there is an optimization flag present.
139   for (unsigned j = 0; j < 4; ++j) {
140     auto &flag = optFlags[j].get();
141     if (flag) {
142       optLevel = j;
143       break;
144     }
145   }
146   return optLevel;
147 }
148 
149 // JIT-compile the given module and run "entryPoint" with "args" as arguments.
150 static Error compileAndExecute(Options &options, ModuleOp module,
151                                StringRef entryPoint,
152                                CompileAndExecuteConfig config, void **args) {
153   Optional<llvm::CodeGenOpt::Level> jitCodeGenOptLevel;
154   if (auto clOptLevel = getCommandLineOptLevel(options))
155     jitCodeGenOptLevel =
156         static_cast<llvm::CodeGenOpt::Level>(clOptLevel.getValue());
157 
158   // If shared library implements custom mlir-runner library init and destroy
159   // functions, we'll use them to register the library with the execution
160   // engine. Otherwise we'll pass library directly to the execution engine.
161   SmallVector<StringRef, 4> libs(options.clSharedLibs.begin(),
162                                  options.clSharedLibs.end());
163 
164   // Libraries that we'll pass to the ExecutionEngine for loading.
165   SmallVector<StringRef, 4> executionEngineLibs;
166 
167   using MlirRunnerInitFn = void (*)(llvm::StringMap<void *> &);
168   using MlirRunnerDestroyFn = void (*)();
169 
170   llvm::StringMap<void *> exportSymbols;
171   SmallVector<MlirRunnerDestroyFn> destroyFns;
172 
173   // Handle libraries that do support mlir-runner init/destroy callbacks.
174   for (auto libPath : libs) {
175     auto lib = llvm::sys::DynamicLibrary::getPermanentLibrary(libPath.data());
176     void *initSym = lib.getAddressOfSymbol("__mlir_runner_init");
177     void *destroySim = lib.getAddressOfSymbol("__mlir_runner_destroy");
178 
179     // Library does not support mlir runner, load it with ExecutionEngine.
180     if (!initSym || !destroySim) {
181       executionEngineLibs.push_back(libPath);
182       continue;
183     }
184 
185     auto initFn = reinterpret_cast<MlirRunnerInitFn>(initSym);
186     initFn(exportSymbols);
187 
188     auto destroyFn = reinterpret_cast<MlirRunnerDestroyFn>(destroySim);
189     destroyFns.push_back(destroyFn);
190   }
191 
192   // Build a runtime symbol map from the config and exported symbols.
193   auto runtimeSymbolMap = [&](llvm::orc::MangleAndInterner interner) {
194     auto symbolMap = config.runtimeSymbolMap ? config.runtimeSymbolMap(interner)
195                                              : llvm::orc::SymbolMap();
196     for (auto &exportSymbol : exportSymbols)
197       symbolMap[interner(exportSymbol.getKey())] =
198           llvm::JITEvaluatedSymbol::fromPointer(exportSymbol.getValue());
199     return symbolMap;
200   };
201 
202   auto expectedEngine = mlir::ExecutionEngine::create(
203       module, config.llvmModuleBuilder, config.transformer, jitCodeGenOptLevel,
204       executionEngineLibs);
205   if (!expectedEngine)
206     return expectedEngine.takeError();
207 
208   auto engine = std::move(*expectedEngine);
209   engine->registerSymbols(runtimeSymbolMap);
210 
211   auto expectedFPtr = engine->lookup(entryPoint);
212   if (!expectedFPtr)
213     return expectedFPtr.takeError();
214 
215   if (options.dumpObjectFile)
216     engine->dumpToObjectFile(options.objectFilename.empty()
217                                  ? options.inputFilename + ".o"
218                                  : options.objectFilename);
219 
220   void (*fptr)(void **) = *expectedFPtr;
221   (*fptr)(args);
222 
223   // Run all dynamic library destroy callbacks to prepare for the shutdown.
224   llvm::for_each(destroyFns, [](MlirRunnerDestroyFn destroy) { destroy(); });
225 
226   return Error::success();
227 }
228 
229 static Error compileAndExecuteVoidFunction(Options &options, ModuleOp module,
230                                            StringRef entryPoint,
231                                            CompileAndExecuteConfig config) {
232   auto mainFunction = module.lookupSymbol<LLVM::LLVMFuncOp>(entryPoint);
233   if (!mainFunction || mainFunction.empty())
234     return make_string_error("entry point not found");
235   void *empty = nullptr;
236   return compileAndExecute(options, module, entryPoint, config, &empty);
237 }
238 
239 template <typename Type>
240 Error checkCompatibleReturnType(LLVM::LLVMFuncOp mainFunction);
241 template <>
242 Error checkCompatibleReturnType<int32_t>(LLVM::LLVMFuncOp mainFunction) {
243   auto resultType = mainFunction.getType()
244                         .cast<LLVM::LLVMFunctionType>()
245                         .getReturnType()
246                         .dyn_cast<IntegerType>();
247   if (!resultType || resultType.getWidth() != 32)
248     return make_string_error("only single i32 function result supported");
249   return Error::success();
250 }
251 template <>
252 Error checkCompatibleReturnType<int64_t>(LLVM::LLVMFuncOp mainFunction) {
253   auto resultType = mainFunction.getType()
254                         .cast<LLVM::LLVMFunctionType>()
255                         .getReturnType()
256                         .dyn_cast<IntegerType>();
257   if (!resultType || resultType.getWidth() != 64)
258     return make_string_error("only single i64 function result supported");
259   return Error::success();
260 }
261 template <>
262 Error checkCompatibleReturnType<float>(LLVM::LLVMFuncOp mainFunction) {
263   if (!mainFunction.getType()
264            .cast<LLVM::LLVMFunctionType>()
265            .getReturnType()
266            .isa<Float32Type>())
267     return make_string_error("only single f32 function result supported");
268   return Error::success();
269 }
270 template <typename Type>
271 Error compileAndExecuteSingleReturnFunction(Options &options, ModuleOp module,
272                                             StringRef entryPoint,
273                                             CompileAndExecuteConfig config) {
274   auto mainFunction = module.lookupSymbol<LLVM::LLVMFuncOp>(entryPoint);
275   if (!mainFunction || mainFunction.isExternal())
276     return make_string_error("entry point not found");
277 
278   if (mainFunction.getType().cast<LLVM::LLVMFunctionType>().getNumParams() != 0)
279     return make_string_error("function inputs not supported");
280 
281   if (Error error = checkCompatibleReturnType<Type>(mainFunction))
282     return error;
283 
284   Type res;
285   struct {
286     void *data;
287   } data;
288   data.data = &res;
289   if (auto error = compileAndExecute(options, module, entryPoint, config,
290                                      (void **)&data))
291     return error;
292 
293   // Intentional printing of the output so we can test.
294   llvm::outs() << res << '\n';
295 
296   return Error::success();
297 }
298 
299 /// Entry point for all CPU runners. Expects the common argc/argv arguments for
300 /// standard C++ main functions.
301 int mlir::JitRunnerMain(int argc, char **argv, const DialectRegistry &registry,
302                         JitRunnerConfig config) {
303   // Create the options struct containing the command line options for the
304   // runner. This must come before the command line options are parsed.
305   Options options;
306   llvm::cl::ParseCommandLineOptions(argc, argv, "MLIR CPU execution driver\n");
307 
308   Optional<unsigned> optLevel = getCommandLineOptLevel(options);
309   SmallVector<std::reference_wrapper<llvm::cl::opt<bool>>, 4> optFlags{
310       options.optO0, options.optO1, options.optO2, options.optO3};
311   unsigned optCLIPosition = 0;
312   // Determine if there is an optimization flag present, and its CLI position
313   // (optCLIPosition).
314   for (unsigned j = 0; j < 4; ++j) {
315     auto &flag = optFlags[j].get();
316     if (flag) {
317       optCLIPosition = flag.getPosition();
318       break;
319     }
320   }
321   // Generate vector of pass information, plus the index at which we should
322   // insert any optimization passes in that vector (optPosition).
323   SmallVector<const llvm::PassInfo *, 4> passes;
324   unsigned optPosition = 0;
325   for (unsigned i = 0, e = options.llvmPasses.size(); i < e; ++i) {
326     passes.push_back(options.llvmPasses[i]);
327     if (optCLIPosition < options.llvmPasses.getPosition(i)) {
328       optPosition = i;
329       optCLIPosition = UINT_MAX; // To ensure we never insert again
330     }
331   }
332 
333   MLIRContext context(registry);
334 
335   auto m = parseMLIRInput(options.inputFilename, &context);
336   if (!m) {
337     llvm::errs() << "could not parse the input IR\n";
338     return 1;
339   }
340 
341   if (config.mlirTransformer)
342     if (failed(config.mlirTransformer(m.get())))
343       return EXIT_FAILURE;
344 
345   auto tmBuilderOrError = llvm::orc::JITTargetMachineBuilder::detectHost();
346   if (!tmBuilderOrError) {
347     llvm::errs() << "Failed to create a JITTargetMachineBuilder for the host\n";
348     return EXIT_FAILURE;
349   }
350   auto tmOrError = tmBuilderOrError->createTargetMachine();
351   if (!tmOrError) {
352     llvm::errs() << "Failed to create a TargetMachine for the host\n";
353     return EXIT_FAILURE;
354   }
355 
356   auto transformer = mlir::makeLLVMPassesTransformer(
357       passes, optLevel, /*targetMachine=*/tmOrError->get(), optPosition);
358 
359   CompileAndExecuteConfig compileAndExecuteConfig;
360   compileAndExecuteConfig.transformer = transformer;
361   compileAndExecuteConfig.llvmModuleBuilder = config.llvmModuleBuilder;
362   compileAndExecuteConfig.runtimeSymbolMap = config.runtimesymbolMap;
363 
364   // Get the function used to compile and execute the module.
365   using CompileAndExecuteFnT =
366       Error (*)(Options &, ModuleOp, StringRef, CompileAndExecuteConfig);
367   auto compileAndExecuteFn =
368       StringSwitch<CompileAndExecuteFnT>(options.mainFuncType.getValue())
369           .Case("i32", compileAndExecuteSingleReturnFunction<int32_t>)
370           .Case("i64", compileAndExecuteSingleReturnFunction<int64_t>)
371           .Case("f32", compileAndExecuteSingleReturnFunction<float>)
372           .Case("void", compileAndExecuteVoidFunction)
373           .Default(nullptr);
374 
375   Error error = compileAndExecuteFn
376                     ? compileAndExecuteFn(options, m.get(),
377                                           options.mainFuncName.getValue(),
378                                           compileAndExecuteConfig)
379                     : make_string_error("unsupported function type");
380 
381   int exitCode = EXIT_SUCCESS;
382   llvm::handleAllErrors(std::move(error),
383                         [&exitCode](const llvm::ErrorInfoBase &info) {
384                           llvm::errs() << "Error: ";
385                           info.log(llvm::errs());
386                           llvm::errs() << '\n';
387                           exitCode = EXIT_FAILURE;
388                         });
389 
390   return exitCode;
391 }
392