[PATCH] D30446: [IndVars] Do not branch on poison

[Sanjoy Das via Phabricator via llvm-commits]

sanjoy created this revision.
Herald added a subscriber: mcrosier.

Earlier, LFTR would introduce branches on values that could
potentially be poison.  This change fixes the issue by demoting the
value LFTR is about to introduce a branch on to a non-poison variant
of itself whenever it cannot statically prove that it isn't poison.

Fixes PR31181.


https://reviews.llvm.org/D30446

Files:
  include/llvm/ADT/STLExtras.h
  lib/Transforms/Scalar/IndVarSimplify.cpp
  test/Transforms/IndVarSimplify/PR31181.ll
  test/Transforms/IndVarSimplify/widen-nsw.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D30446.89979.patch
Type: text/x-patch
Size: 8989 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170228/762206b7/attachment-0001.bin>