[PATCH] D48584: [InstCombine] Delay foldICmpUsingKnownBits until simple transforms are done

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In https://reviews.llvm.org/D48584#1143257, @mkazantsev wrote:

> In https://reviews.llvm.org/D48584#1143240, @lebedev.ri wrote:
>
> > This only moves the `foldICmpUsingKnownBits()` call later on,
> >  but in PR37636 <https://bugs.llvm.org/show_bug.cgi?id=37636#c4> @spatel suggests it *might* expose more problems.
> >  Does this expose any problems?
>
>
> From my point of view, no. We use different predicates in some cases, I am not convinced that either of them is better (at least less/greater predicates are more useful for SCEV analysis than ne/eq).
>  I'll fix the comments.


The test diffs here show what I was concerned about. It's not clear to me if/when the predicate/constant changes in these compares are wins or not. It's probably in the noise, but we should check for regressions on test-suite or some other benchmark?


https://reviews.llvm.org/D48584