[LLVMdev] Transforming SwitchInst to BranchInst (original) (raw)

Pete Cooper peter_cooper at apple.com
Fri Jul 24 11:05:23 PDT 2015

Hi Zhoulai

If you just don’t want any switch statements, then take a look at LowerSwitch.cpp. I think it will do what you want.

You can also invoke it with ‘opt -lowerswitch ...’.

Thanks, Pete

On Jul 24, 2015, at 10:46 AM, Zhoulai <zell08v at gmail.com> wrote:

Hi, Are there some built-in LLVM transformation pass, or written library code that transforms LLVM::SwitchInst into if-condition statements (LLVM:: BranchInst)? The purpose of the transformation is that we have a legacy program analyzer that includes an LLVM pass manipulating if-condition statements. Statements of LLVM::SwithchInst should have been handled in the same manner but was not done. Thus to transform these SwitchInst to if-condition looks a viable alternative for us. To illustrate, I give a simple C snippet with 'switch' and the expected transformation. ---------------------------------------- Original program: char grade; ... switch(grade) { case 'A' : printf("Excellent!\n" ); break; case 'B' : printf("Well done\n" ); break; default : printf("Invalid grade\n" ); } may be transformed to something like if (grad=='A') printf("Excellent!\n" ); else if (grad=='B') printf("Well done\n" ); else printf("Invalid grade\n" ); ------------------------------------------------- Are you aware of such a transformation pass ? Thanks. Zhoulai

LLVM Developers mailing list LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150724/c7053060/attachment.html>

More information about the llvm-dev mailing list