How to transform loop to if-else using LLVM?

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1

Hello everyone,

Sorry to bother you. I’m an undergraduate, and I’m trying to finish my graduation project using LLVM. In this project, I hope to transform all loop in program to condition statement. For example,
Before transformation: for (int i = 0; i < 5; i++) a++;
After transformation: int i = 0; if (i < 5) a++; i++;
The idea is very clear, however, I’m a newbie to LLVM. After read code of some LLVM’s transformation, I still have no idea of how to implement this idea.
Hope you can give me some hint. Thank you very much!

2

Hi, Zhiyuan Yang,

Are you trying to replace the for-loop with equivalent if-goto loop? In this case, do you also need a goto after i++?
LLVM IR in fact already contains exactly the goto-form of any loop, because IR has no high-level constructs like for or while.

  • D.

2013/4/17 zhiyuan yang <sjtu.yzy@gmail.com>