[PATCH] D27004: Set unroll remainder to epilog if profitable

[Michael Zolotukhin via Phabricator via llvm-commits]

mzolotukhin added inline comments.


================
Comment at: test/Transforms/LoopUnroll/epilog_const_phi.ll:4
+; Epilog unroll allows to keep PHI constant value.
+; For the test this means that inscombine can completle eliminate XOR.
+
----------------
s/inscombine/instcombine/
s/completle/completely/

I'd rather not rely on other passes (instcombine) to check loop-unroll. Can we check the CFG instead? That'll make the test smaller (since it'll be enough to have a minimal loop) and more robust to unrelated changes (say, instcombine for some reason stopped to simplify XOR through phis). It would be also nice to have a test, in which we don't use epilog (i.e. arguments of phis are not constant), to check that we're not doing it everywhere.


Repository:
  rL LLVM

https://reviews.llvm.org/D27004