#include "BasicBlock.h"
#include "Constant.h"
#include "Function.h"
#include "IRStmtBuilder.h"
#include "Module.h"
#include "Type.h"

#include <iostream>
#include <memory>

#ifdef DEBUG  // 用于调试信息,大家可以在编译过程中通过" -DDEBUG"来开启这一选项
#define DEBUG_OUTPUT std::cout << __LINE__ << std::endl;  // 输出行号的简单示例
#else
#define DEBUG_OUTPUT
#endif

#define CONST_INT(num) \
    ConstantInt::create(num, module)

#define CONST_FP(num) \
    ConstantFloat::create(num, module) // 得到常数值的表示,方便后面多次用到

using namespace SysYF::IR;

int main(){
    auto module = Module::create("sysYF while");
    auto builder = IRStmtBuilder::create(nullptr, module);
    SysYF::Ptr<Type> Int32Type = Type::get_int32_type(module);
    auto zero_initializer = ConstantZero::create(Int32Type, module);
    auto b = GlobalVariable::create("b", module, Int32Type, false, zero_initializer);//int b=0;
    auto a = GlobalVariable::create("a", module, Int32Type, false, CONST_INT(3));//int a=3;
    //main函数

    auto mainFunTy = FunctionType::create(Int32Type, {});//main函数没有参数
    auto mainFun = Function::create(mainFunTy, "main", module);//创建main函数

    auto bb = BasicBlock::create(module, "entry",mainFun);//创建一个名为entry的基本块
    builder->set_insert_point(bb);                        // 一个BB的开始,将当前插入指令点的位置设在bb
    // while(a>0){	
	// 	b = b+a;
	// 	a = a-1;
	// }
	// return b;
    builder->create_store(CONST_INT(0), b);//b=0
    builder->create_store(CONST_INT(3), a);//a=3
    auto condBB = BasicBlock::create(module, "condBB", mainFun);
    auto whileBB = BasicBlock::create(module, "trueBB_while", mainFun);
    auto falseBB = BasicBlock::create(module, "falseBB_while", mainFun);

    //无条件br
    builder->create_br(condBB);//goto condBB
    //condBB
    builder->set_insert_point(condBB);
    auto aLoad = builder->create_load(a);//a
    auto icmp = builder->create_icmp_gt(aLoad, CONST_INT(0));//a>0
    //条件br
    builder->create_cond_br(icmp, whileBB, falseBB);//if(a>0) goto whileBB; else goto falseBB;
    
    //whileBB
    builder->set_insert_point(whileBB);
    auto bLoad = builder->create_load(b);//b
    //b = b+a
    auto bAdda = builder->create_iadd(bLoad, aLoad);//b+a
    builder->create_store(bAdda, b);//b=b+a
    //a = a-1
    auto aSub1 = builder->create_isub(aLoad, CONST_INT(1));//a-1
    builder->create_store(aSub1, a);//a=a-1
    //无条件br
    builder->create_br(condBB);//goto condBB

    //falseBB
    builder->set_insert_point(falseBB);
    auto bLoadr = builder->create_load(b);//b
    builder->create_ret(bLoadr);//return b

    std::cout << module->print();
    return 0;
}