On 2/20/25 12:38 AM, Richard Biener wrote:
On Wed, 19 Feb 2025, Jeff Law wrote:
On 2/15/25 6:36 AM, Richard Biener wrote:
The PR indicates a very specific issue with regard to SSA coalescing
failures because there's a pre IV increment loop exit test. While
IVOPTs created the desired IL we later simplify the exit test into
the undesirable form again. The following fixes this up during RTL
expansion where we try to improve coalescing of IVs. That seems
easier that trying to avoid the simplification with some weird
heuristics (it could also have been written this way).
Ugh. I think we've got hacks in multiple places to deal with similar issues.
One could ask the question if one or more of those could be removed, though
clearly that's gcc-16 material.
I think they are all in this place (and rightfully so). If you
remember others elsewhere I'd like to know ;)
There's "simple_iv_increment_p" and its uses in DOM. But I think that
was inherited from somewhere else, though perhaps those other cases have
since been removed.
Thanks, pushed (clearing through old regressins assigned to me...)
I'm going through them as well (as you probably guessed). Though I'm
not terribly selective. Whatever looks like it might be solvable.
jeff
