examples/LLJITExamples/LLJITWithObjectCache/LLJITWithObjectCache.cpp

   1 //===--- LLJITWithObjectCache.cpp - An LLJIT example with an ObjectCache --===//
   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 "llvm/ADT/StringMap.h"
  10 #include "llvm/ExecutionEngine/ObjectCache.h"
  11 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
  12 #include "llvm/IR/Function.h"
  13 #include "llvm/IR/IRBuilder.h"
  14 #include "llvm/IR/Module.h"
  15 #include "llvm/Support/InitLLVM.h"
  16 #include "llvm/Support/TargetSelect.h"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 #include "../ExampleModules.h"
  20
  21 using namespace llvm;
  22 using namespace llvm::orc;
  23
  24 ExitOnError ExitOnErr;
  25
  26 class MyObjectCache : public ObjectCache {
  27 public:
  28   void notifyObjectCompiled(const Module *M,
  29                             MemoryBufferRef ObjBuffer) override {
  30     CachedObjects[M->getModuleIdentifier()] = MemoryBuffer::getMemBufferCopy(
  31         ObjBuffer.getBuffer(), ObjBuffer.getBufferIdentifier());
  32   }
  33
  34   std::unique_ptr<MemoryBuffer> getObject(const Module *M) override {
  35     auto I = CachedObjects.find(M->getModuleIdentifier());
  36     if (I == CachedObjects.end()) {
  37       dbgs() << "No object for " << M->getModuleIdentifier()
  38              << " in cache. Compiling.\n";
  39       return nullptr;
  40     }
  41
  42     dbgs() << "Object for " << M->getModuleIdentifier()
  43            << " loaded from cache.\n";
  44     return MemoryBuffer::getMemBuffer(I->second->getMemBufferRef());
  45   }
  46
  47 private:
  48   StringMap<std::unique_ptr<MemoryBuffer>> CachedObjects;
  49 };
  50
  51 void runJITWithCache(ObjectCache &ObjCache) {
  52
  53   // Create an LLJIT instance with a custom CompileFunction.
  54   auto J = ExitOnErr(
  55       LLJITBuilder()
  56           .setCompileFunctionCreator(
  57               [&](JITTargetMachineBuilder JTMB)
  58                   -> Expected<IRCompileLayer::CompileFunction> {
  59                 auto TM = JTMB.createTargetMachine();
  60                 if (!TM)
  61                   return TM.takeError();
  62                 return IRCompileLayer::CompileFunction(
  63                     TMOwningSimpleCompiler(std::move(*TM), &ObjCache));
  64               })
  65           .create());
  66
  67   auto M = ExitOnErr(parseExampleModule(Add1Example, "add1"));
  68
  69   ExitOnErr(J->addIRModule(std::move(M)));
  70
  71   // Look up the JIT'd function, cast it to a function pointer, then call it.
  72   auto Add1Sym = ExitOnErr(J->lookup("add1"));
  73   int (*Add1)(int) = (int (*)(int))Add1Sym.getAddress();
  74
  75   int Result = Add1(42);
  76   outs() << "add1(42) = " << Result << "\n";
  77 }
  78
  79 int main(int argc, char *argv[]) {
  80   // Initialize LLVM.
  81   InitLLVM X(argc, argv);
  82
  83   InitializeNativeTarget();
  84   InitializeNativeTargetAsmPrinter();
  85
  86   cl::ParseCommandLineOptions(argc, argv, "HowToUseLLJIT");
  87   ExitOnErr.setBanner(std::string(argv[0]) + ": ");
  88
  89   MyObjectCache MyCache;
  90
  91   runJITWithCache(MyCache);
  92   runJITWithCache(MyCache);
  93
  94   return 0;
  95 }