用verilog语言编写的CLA_4文件。CLA_4是4位超前进位加法器的源代码，该代码验证后功能正确，读者可以自行编写testbench代码进行验证。-With verilog language CLA 4 files. CLA 4 is a four-ahead adder source code after the code verification function correctly, readers can write their own testbench code for verification.