[PATCH] D32086: [DAG] Improve store merge candidate pruning.

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

The limitations of store merging aren't clear to me. Can you add a code comment about why this is necessary? I would have assumed that we'd merge the later consecutive stores when visiting them because we visited them first.
Also, it would be better to add a more obvious test case. I think this should work as an x86 test:

  ; Don't let a non-consecutive store thwart merging of the last two.
  define void @almost_consecutive_stores(i8* %p) {
  store i8 0, i8* %p
  %p1 = getelementptr i8, i8* %p, i64 42
  store i8 1, i8* %p1
  %p2 = getelementptr i8, i8* %p, i64 2
  store i8 2, i8* %p2
  %p3 = getelementptr i8, i8* %p, i64 3
  store i8 3, i8* %p3
  ret void
  }

If that's correct, can you add that test as an NFC change ahead of this patch, so we just see the diff from your patch? Thanks.


https://reviews.llvm.org/D32086