tree c42e2fe80d04fddd3e9b6e2e78f5de16088eb7ec
parent 5865df5baae7b74fa87311ce3867244183cc1325
author Max Kazantsev <max.kazantsev@azul.com> 1547729470 +0000
committer Max Kazantsev <max.kazantsev@azul.com> 1547729470 +0000

[LoopSimplifyCFG] Form LCSSA when a parent loop becomes a sibling

During the transforms in LoopSimplifyCFG, when we remove a dead exiting edge, the
parent loop may stop being reachable from the child loop, and therefore they become
siblings. If the former child loop had uses of some values from its former parent loop,
now such uses will require LCSSA Phis, even if they weren't needed before. So we must
form LCSSA for all loops that stopped being ancestors of the current loop in this case.

Differential Revision: https://reviews.llvm.org/D56144
Reviewed By: fedor.sergeev


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351434 91177308-0d34-0410-b5e6-96231b3b80d8