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