[LLVMdev] How to unroll loop with non-constant boundary

Benjamin Kramer benny.kra at googlemail.com
Tue Feb 28 05:41:16 PST 2012

On 27.02.2012, at 20:17, Duncan Sands wrote:

> Hi Benjamin,
>> LLVM misses this optimization because ScalarEvolution's ComputeExitLimitFromICmp doesn't handle signed<= (SLE) and thus can't compute the number of times the loop is executed. I wonder if there's a reason for this, it seems like something simple to add.
> instsimplify could also be enhanced to clean it up in this particular case, but
> it would be better to make scev smarter.

I filed http://llvm.org/bugs/show_bug.cgi?id=12110 to track this.

- Ben

> Ciao, Duncan.
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

More information about the llvm-dev mailing list