This is a latent bug that's been hanging around for a while. For a loop-invariant
pointer, expandBounds would return the range {Ptr, Ptr}, but this was interpreted
as a half-open range, not a closed range. So we ended up planting incorrect
bounds checks. Even worse, they were tautological, so we ended up incorrectly
executing the optimized loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299526 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If LAA expands a bound that is loop invariant, but not hoisted out
of the loop body, it used to use that value anyway, causing a
non-domination error, because the memcheck block is of course not
dominated by the scalar loop body. Detect this situation and expand
the SCEV expression instead.
Fixes PR31251
Reviewers: anemet
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D27397
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288705 91177308-0d34-0410-b5e6-96231b3b80d8
