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

[Benjamin Kramer]

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.
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