gcc源码分析GIMPLIFY相关四、GIMPLIFY相关4.1gcc全局符号表与符号分析4.1.1全局符号表4.1.2函数节点的gimplify4.2gimple高端化4.2.1gimplify_body函数4.2.2gimplify_stmt4.3gimple低端化4.3.1pass_lower_cf4.3.2pass_build_cfg4.3.3p