[PATCH] D43876: [LoopUnroll] Peel off iterations if it makes conditions true/false.

[Jun Bum Lim via Phabricator via llvm-commits]

junbuml added a comment.

> My transform selects a region of conditionally executed blocks and then attempts to hoist conditional statements into the head block of that region.

Will your pass merge some blocks under same condition into a group in the loop? I'm curious if the conditional branch is removed in the loop?

> Just FYI, I am also currently working on a pass to handle slightly more generic cases within the loop body, such like:
> 
>   for (unsigned i = 0; i; i < 1000; ++i) {
>     if (i < M)
>       ... something
>     else
>       ... something else
>   }
> 
> My transformation operates on the unrolled version and also attempts to remove selects if the loop body has been simplified into one block. Hopefully I will be able to get an initial version up for review and discussion next week.

I'm not sure if I fully understand what your pass will do. It would be great if you can show how this code would be transformed after your pass ?


https://reviews.llvm.org/D43876