Home | History | Annotate | Download | only in Chapter2 
      1 //===----- KaleidoscopeJIT.h - A simple JIT for Kaleidoscope ----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // Contains a simple JIT definition for use in the kaleidoscope tutorials.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
     15 #define LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
     16 
     17 #include "llvm/ADT/STLExtras.h"
     18 #include "llvm/ExecutionEngine/ExecutionEngine.h"
     19 #include "llvm/ExecutionEngine/RuntimeDyld.h"
     20 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
     21 #include "llvm/ExecutionEngine/Orc/CompileUtils.h"
     22 #include "llvm/ExecutionEngine/Orc/JITSymbol.h"
     23 #include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
     24 #include "llvm/ExecutionEngine/Orc/IRTransformLayer.h"
     25 #include "llvm/ExecutionEngine/Orc/LambdaResolver.h"
     26 #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
     27 #include "llvm/IR/DataLayout.h"
     28 #include "llvm/IR/Mangler.h"
     29 #include "llvm/Support/DynamicLibrary.h"
     30 #include "llvm/Support/raw_ostream.h"
     31 #include "llvm/Target/TargetMachine.h"
     32 #include <algorithm>
     33 #include <memory>
     34 #include <string>
     35 #include <vector>
     36 
     37 namespace llvm {
     38 namespace orc {
     39 
     40 class KaleidoscopeJIT {
     41 private:
     42   std::unique_ptr<TargetMachine> TM;
     43   const DataLayout DL;
     44   ObjectLinkingLayer<> ObjectLayer;
     45   IRCompileLayer<decltype(ObjectLayer)> CompileLayer;
     46 
     47   typedef std::function<std::unique_ptr<Module>(std::unique_ptr<Module>)>
     48     OptimizeFunction;
     49 
     50   IRTransformLayer<decltype(CompileLayer), OptimizeFunction> OptimizeLayer;
     51 
     52 public:
     53   typedef decltype(OptimizeLayer)::ModuleSetHandleT ModuleHandle;
     54 
     55   KaleidoscopeJIT()
     56       : TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()),
     57         CompileLayer(ObjectLayer, SimpleCompiler(*TM)),
     58         OptimizeLayer(CompileLayer,
     59                       [this](std::unique_ptr<Module> M) {
     60                         return optimizeModule(std::move(M));
     61                       }) {
     62     llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
     63   }
     64 
     65   TargetMachine &getTargetMachine() { return *TM; }
     66 
     67   ModuleHandle addModule(std::unique_ptr<Module> M) {
     68     // Build our symbol resolver:
     69     // Lambda 1: Look back into the JIT itself to find symbols that are part of
     70     //           the same "logical dylib".
     71     // Lambda 2: Search for external symbols in the host process.
     72     auto Resolver = createLambdaResolver(
     73         [&](const std::string &Name) {
     74           if (auto Sym = OptimizeLayer.findSymbol(Name, false))
     75             return Sym.toRuntimeDyldSymbol();
     76           return RuntimeDyld::SymbolInfo(nullptr);
     77         },
     78         [](const std::string &Name) {
     79           if (auto SymAddr =
     80                 RTDyldMemoryManager::getSymbolAddressInProcess(Name))
     81             return RuntimeDyld::SymbolInfo(SymAddr, JITSymbolFlags::Exported);
     82           return RuntimeDyld::SymbolInfo(nullptr);
     83         });
     84 
     85     // Build a singlton module set to hold our module.
     86     std::vector<std::unique_ptr<Module>> Ms;
     87     Ms.push_back(std::move(M));
     88 
     89     // Add the set to the JIT with the resolver we created above and a newly
     90     // created SectionMemoryManager.
     91     return OptimizeLayer.addModuleSet(std::move(Ms),
     92                                       make_unique<SectionMemoryManager>(),
     93                                       std::move(Resolver));
     94   }
     95 
     96   JITSymbol findSymbol(const std::string Name) {
     97     std::string MangledName;
     98     raw_string_ostream MangledNameStream(MangledName);
     99     Mangler::getNameWithPrefix(MangledNameStream, Name, DL);
    100     return OptimizeLayer.findSymbol(MangledNameStream.str(), true);
    101   }
    102 
    103   void removeModule(ModuleHandle H) {
    104     OptimizeLayer.removeModuleSet(H);
    105   }
    106 
    107 private:
    108 
    109   std::unique_ptr<Module> optimizeModule(std::unique_ptr<Module> M) {
    110     // Create a function pass manager.
    111     auto FPM = llvm::make_unique<legacy::FunctionPassManager>(M.get());
    112 
    113     // Add some optimizations.
    114     FPM->add(createInstructionCombiningPass());
    115     FPM->add(createReassociatePass());
    116     FPM->add(createGVNPass());
    117     FPM->add(createCFGSimplificationPass());
    118     FPM->doInitialization();
    119 
    120     // Run the optimizations over all functions in the module being added to
    121     // the JIT.
    122     for (auto &F : *M)
    123       FPM->run(F);
    124 
    125     return M;
    126   }
    127 
    128 };
    129 
    130 } // end namespace orc
    131 } // end namespace llvm
    132 
    133 #endif // LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
    134