forked from OSchip/llvm-project
83 lines
2.8 KiB
C++
83 lines
2.8 KiB
C++
//===-- examples/HowToUseJIT/HowToUseJIT.cpp - An example use of the JIT --===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ExecutionEngine/Orc/LLJIT.h"
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Support/InitLLVM.h"
|
|
#include "llvm/Support/TargetSelect.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
|
|
using namespace llvm;
|
|
using namespace llvm::orc;
|
|
|
|
ExitOnError ExitOnErr;
|
|
|
|
ThreadSafeModule createDemoModule() {
|
|
auto Context = std::make_unique<LLVMContext>();
|
|
auto M = std::make_unique<Module>("test", *Context);
|
|
|
|
// Create the add1 function entry and insert this entry into module M. The
|
|
// function will have a return type of "int" and take an argument of "int".
|
|
Function *Add1F =
|
|
Function::Create(FunctionType::get(Type::getInt32Ty(*Context),
|
|
{Type::getInt32Ty(*Context)}, false),
|
|
Function::ExternalLinkage, "add1", M.get());
|
|
|
|
// Add a basic block to the function. As before, it automatically inserts
|
|
// because of the last argument.
|
|
BasicBlock *BB = BasicBlock::Create(*Context, "EntryBlock", Add1F);
|
|
|
|
// Create a basic block builder with default parameters. The builder will
|
|
// automatically append instructions to the basic block `BB'.
|
|
IRBuilder<> builder(BB);
|
|
|
|
// Get pointers to the constant `1'.
|
|
Value *One = builder.getInt32(1);
|
|
|
|
// Get pointers to the integer argument of the add1 function...
|
|
assert(Add1F->arg_begin() != Add1F->arg_end()); // Make sure there's an arg
|
|
Argument *ArgX = &*Add1F->arg_begin(); // Get the arg
|
|
ArgX->setName("AnArg"); // Give it a nice symbolic name for fun.
|
|
|
|
// Create the add instruction, inserting it into the end of BB.
|
|
Value *Add = builder.CreateAdd(One, ArgX);
|
|
|
|
// Create the return instruction and add it to the basic block
|
|
builder.CreateRet(Add);
|
|
|
|
return ThreadSafeModule(std::move(M), std::move(Context));
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
// Initialize LLVM.
|
|
InitLLVM X(argc, argv);
|
|
|
|
InitializeNativeTarget();
|
|
InitializeNativeTargetAsmPrinter();
|
|
|
|
cl::ParseCommandLineOptions(argc, argv, "HowToUseLLJIT");
|
|
ExitOnErr.setBanner(std::string(argv[0]) + ": ");
|
|
|
|
// Create an LLJIT instance.
|
|
auto J = ExitOnErr(LLJITBuilder().create());
|
|
auto M = createDemoModule();
|
|
|
|
ExitOnErr(J->addIRModule(std::move(M)));
|
|
|
|
// Look up the JIT'd function, cast it to a function pointer, then call it.
|
|
auto Add1Sym = ExitOnErr(J->lookup("add1"));
|
|
int (*Add1)(int) = (int (*)(int))Add1Sym.getAddress();
|
|
|
|
int Result = Add1(42);
|
|
outs() << "add1(42) = " << Result << "\n";
|
|
|
|
return 0;
|
|
}
|