Created
December 12, 2012 17:38
-
-
Save jeremyroman/4269878 to your computer and use it in GitHub Desktop.
llvm-brainfuck: Simple operations
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <cstdio> | |
#include <llvm/LLVMContext.h> | |
#include <llvm/Module.h> | |
#include <llvm/Support/IRBuilder.h> | |
#include <llvm/Support/raw_ostream.h> | |
using namespace llvm; | |
static const uint64_t DATA_SIZE = 30000; | |
static const char *DATA_NAME = "data"; | |
static const char *PTR_NAME = "ptr"; | |
int main() { | |
// LLVM context. | |
LLVMContext &Context = getGlobalContext(); | |
Module MainModule("brainfuck program", Context); | |
IRBuilder<> Builder(Context); | |
// Some useful constants. | |
const IntegerType *CellType = Type::getInt8Ty(Context); | |
Constant *One = ConstantInt::get(CellType, 1); | |
// Global data for a brainfuck program. | |
ArrayType *DataType = ArrayType::get(CellType, DATA_SIZE); | |
GlobalVariable *Data = new GlobalVariable( | |
MainModule, DataType, false /* constant */, | |
GlobalVariable::InternalLinkage, Constant::getNullValue(DataType), | |
DATA_NAME); | |
Value *DataPtr = Builder.CreateConstInBoundsGEP2_32(Data, 0, 0, PTR_NAME); | |
(void) DataPtr; // unused | |
// Main function definition. | |
FunctionType *MainFunctionType = FunctionType::get( | |
Type::getVoidTy(Context) /* return type */, | |
std::vector<const Type *>() /* argument types */, | |
false /* var args */); | |
Function *MainFunction = Function::Create(MainFunctionType, | |
Function::ExternalLinkage, "brainfuck_main", &MainModule); | |
BasicBlock *MainBlock = BasicBlock::Create(Context, "entry", MainFunction); | |
Builder.SetInsertPoint(MainBlock); | |
// Code generation. | |
int c; | |
Value *Value; | |
while ((c = getchar()) != EOF) { | |
switch (c) { | |
case '>': | |
DataPtr = Builder.CreateConstGEP1_32(DataPtr, 1, PTR_NAME); | |
break; | |
case '<': | |
DataPtr = Builder.CreateConstGEP1_32(DataPtr, -1, PTR_NAME); | |
break; | |
case '+': | |
Value = Builder.CreateLoad(DataPtr); | |
Value = Builder.CreateAdd(Value, One); | |
Builder.CreateStore(Value, DataPtr); | |
break; | |
case '-': | |
Value = Builder.CreateLoad(DataPtr); | |
Value = Builder.CreateSub(Value, One); | |
Builder.CreateStore(Value, DataPtr); | |
break; | |
} | |
} | |
// Finish off brainfuck_main and dump. | |
Builder.CreateRetVoid(); | |
MainModule.print(outs(), NULL /* assembly annotation writer */); | |
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
PROGRAM := llvm-brainfuck | |
OBJECTS := main.o | |
CXX := clang++ | |
CXXFLAGS := $(shell llvm-config --cppflags) -Wall -Werror -pedantic | |
LDFLAGS := $(shell llvm-config --ldflags --libs core) | |
all: $(PROGRAM) $(SHIM) | |
$(PROGRAM): $(OBJECTS) | |
$(CXX) -o $@ $^ $(LDFLAGS) | |
clean: | |
rm -f $(PROGRAM) $(OBJECTS) | |
.PHONY: clean all |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment