[IndVars] Preserve LCSSA in `eliminateIdentitySCEV`
Summary:
After r249211, SCEV can see through some LCSSA phis. Add a
`replacementPreservesLCSSAForm` check before replacing uses of these phi
nodes with a simplified use of the induction variable to avoid breaking
LCSSA.
Fixes 25047.
Depends on D13460.
Reviewers: atrick, hfinkel
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13461
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249575 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed