[PATCH] D138872: [InstCombine] canonicalize trunc + insert as bitcast + shuffle, part 1

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri accepted this revision.
lebedev.ri added a comment.

In D138872#3960604 <https://reviews.llvm.org/D138872#3960604>, @spatel wrote:

> Patch updated:
>
> 1. Added documentation comment for the general transform.
> 2. Added TODO for one-use restriction.

Actually, i guess i was thinking about canonicalizing all insertelements @ constant idx into shuffles
(+the shuffle to convert the scalar into an appropriately-sized vector),
but i guess that is almost borderline bad?
So LG i suppose.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138872/new/

https://reviews.llvm.org/D138872