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#include "BasicBlock.h"
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#include "Constant.h"
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#include "Function.h"
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#include "IRStmtBuilder.h"
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#include "Module.h"
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#include "Type.h"
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#include <iostream>
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#include <memory>
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#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
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#define DEBUG_OUTPUT std::cout << __LINE__ << std::endl; // 输出行号的简单示例
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#else
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#define DEBUG_OUTPUT
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#endif
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#define CONST_INT(num) \
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ConstantInt::create(num, module)
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#define CONST_FP(num) \
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ConstantFloat::create(num, module) // 得到常数值的表示,方便后面多次用到
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using namespace SysYF::IR;
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int main() {
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auto module = Module::create("if_test.sy"); // module name是if_test
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auto builder = IRStmtBuilder::create(nullptr, module);
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SysYF::Ptr<Type> Int32Type = Type::get_int32_type(module);
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// 生成全局变量a, b
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auto zero_initializer = ConstantZero::create(Int32Type, module);
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auto a = GlobalVariable::create("a", module, Int32Type, false, zero_initializer);
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auto b = GlobalVariable::create("b", module, Int32Type, false, zero_initializer);
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// 生成main函数
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auto mainFun = Function::create(FunctionType::create(Int32Type, {}),
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"main", module);
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// 生成一个基本块并进入
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auto entry = BasicBlock::create(module, "entry", mainFun);
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builder->set_insert_point(entry);
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// 给b,a赋值0,3
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builder->create_store(CONST_INT(0), b);
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builder->create_store(CONST_INT(3), a);
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// 设置三个BasicBlock
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auto while_cond = BasicBlock::create(module, "while_cond", mainFun);
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auto while_body = BasicBlock::create(module, "while_body", mainFun);
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auto while_end = BasicBlock::create(module, "while_end", mainFun);
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// 跳转while_cond
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builder->create_br(while_cond);
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// while_cond
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builder->set_insert_point(while_cond);
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// 把a加载到寄存器
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auto aReg = builder->create_load(a);
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// 创造一个比较语句，就是说a>0
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auto icmp = builder->create_icmp_gt(aReg, CONST_INT(0)); // n和4的比较
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// 创建一个分支br
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builder->create_cond_br(icmp, while_body, while_end);
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// while_body
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builder->set_insert_point(while_body);
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// b = b + 1
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auto aReg2 = builder->create_load(a);
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auto bReg2 = builder->create_load(b);
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auto abReg = builder->create_iadd(aReg2, bReg2);
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builder->create_store(abReg, b);
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// a = a - 1，此时可以优化编译流程，不重新加载a
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auto aReg3 = builder->create_isub(aReg2, CONST_INT(1));
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builder->create_store(aReg3, a);
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// 跳转
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builder->create_br(while_cond);
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// while_body
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builder->set_insert_point(while_end);
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// 构建假的返回
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auto bReg3 = builder->create_load(b);
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builder->create_ret(bReg3);
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std::cout << module->print();
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return 0;
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}
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