[PATCH] D21720: Unroll for uncountable loops

[Evgeny Stupachenko via Phabricator via llvm-commits]

evstupac added a comment.

Hi Michael,

>> but we shouldn't forget about the increased source code complexity.

The patch mostly reuse existing code for full unroll.

Regarding PHI Cycle it even improve current heuristic, as full unroll consider
"s^=1;" is constant "1" at all iterations >0. However it is 0 on even and 1 on odd.
And I'm ok to drop this part to make code shorter.

Maybe we can add uncountable loops unroll under -O3?

Thanks,
Evgeny


Repository:
  rL LLVM

https://reviews.llvm.org/D21720