[PATCH] D35035: [InstCombine] Prevent memcpy generation for small data size

[JF Bastien via Phabricator via llvm-commits]

jfb added a comment.

In https://reviews.llvm.org/D35035#1282236, @spatel wrote:

> In https://reviews.llvm.org/D35035#1281462, @lebedev.ri wrote:
>
> > Not sure what is the general consensus wrt this patch, but i guess it now consistently uses bytes.
>
>
> Agree - the code change looks like what I expected now.
>
> So:
>
> 1. Is @jfb objecting to this as an intermediate improvement?


My concern is here: https://reviews.llvm.org/D35035#inline-464768
This uses an unrelated constant to drive optimization decisions. Create a new per-target constant.

> 2. If not, there are unanswered comments about the test diffs.
> 3. There was also an unanswered request for the targets and size/perf improvements for this change (presumably some 32-bit target shows wins).
> 4. Are there any updates on the perf for the ideal change (removing this expansion completely)?

I do want to see size and perf results.


Repository:
  rL LLVM

https://reviews.llvm.org/D35035