title: Is there an llvm function to find the set of live variables at each program point?
body: <p>I am writing an analysis pass for partially dead variables. For doing so I need the information about the live variables at a given program point. Is there an LLVM function that can return the set of live variables at a given program point? or do I have to write my own liveness analysis pass?</p>
  <p>Searching for such function lead me to the documentation of isLiveIn() and isLiveOut() functions but I am not able to understand how do I use them. Also these function return a bool saying whether a reg is live or not but instead I need to know all set of registers/variables that are live at a program point. So it does not solve my problem either.</p>
  <p>P:I am a newbie in writing llvm passes.</p>