[InstCombine] add helper for icmp with dominator; NFC
There's a potential small enhancement to this code that could
solve the cases currently under proposal in D54827 via SimplifyCFG.
Whether instcombine should be doing this kind of semi-non-local
analysis in the first place is an open question, but separating
the logic out can only help if/when we decide to move it to a
different pass.
AFAICT, any proposal to do this in SimplifyCFG could also be seen
as an overreach + it would be incomplete to start the fold from a
branch rather than an icmp.
There's another question here about the code for processUGT_ADDCST_ADD().
That part may be completely dead after rL234638 ?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348273 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed