[PATCH] D62144: [LoopUnroll] Add FlagNUW for backedge count

[Sam Parker via Phabricator via llvm-commits]

samparker created this revision.
samparker added reviewers: anna, dmgreen, mkazantsev.
Herald added subscribers: sanjoy, zzheng.
samparker added a parent revision: D61934: [SCEV] Add wrap flags while expanding Add.

While performing runtime unrolling, we assign the backedge taken count as TripCount - 1. So, if we can prove that TripCount > 0, then we know that the backedge count is nuw.


https://reviews.llvm.org/D62144

Files:
  lib/Transforms/Utils/LoopUnrollRuntime.cpp
  test/Transforms/IndVarSimplify/lftr.ll
  test/Transforms/LoopUnroll/nuw-backedge.ll
  test/Transforms/LoopUnroll/runtime-unroll-remainder.ll
  test/Transforms/LoopUnrollAndJam/unroll-and-jam.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D62144.200288.patch
Type: text/x-patch
Size: 5094 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190520/b4645e1c/attachment.bin>