opt dot-cfg source code


I am using the opt tool in llvm to help me generate the cfg from the llvm bitcode. Something like below

Node0x9453f70:s0 → Node0x94545e0;
Node0x9453f70:s1 → Node0x9454630;

First, I would like to know what does the address mean? 0x9453f70. Is it randomly generated or some specific meaning.

Second, what does s0 and s1 mean…why the same address may have two node.

Third, which is the most important to me. Are there any methods that I can get the source line information. Here I can only draw a graph based on LLVM IR level. Can we get the source line information? Any option or do I have to write a specific LLVM Pass. Many Thanks