- User Since
- Jul 7 2012, 2:54 PM (394 w, 3 d)
Dec 26 2019
Can we add an LLVM test w/ the metadata so that we have an entirely LLVM test flow that ensures the pass builder DTRT?
Dec 16 2019
Just wanted to say thanks for the performance data! I know it was hard to get, but it is really, really useful to help folks evaluate these kinds of changes with actual data around the options available.
Dec 10 2019
I just want to mention here, that my comment on the original patch still stands and really needs to be addressed:
Dec 3 2019
I'm seeing lots of updates to fix bugs, but no movement for many days on both my meta comments and (in some ways more importantly) James's meta comments. (And thanks Philip for chiming in too!)
Nov 30 2019
Nov 24 2019
Minor nits around redundant predicates for SROA. With thouse fixed, LGTM.
(Just a reminder that we need to have both performance and code size numbers for this patch. And given that there are a few options, may need a few examples.)
Nov 13 2019
Thanks for sending this out!
Oct 23 2019
A few minor further tweaks.
More fixes from Manuel.
Address feedback from Manuel.
Oct 17 2019
Generally very happy with this. Would like Eric to check this as well to think about the C API and other things that we maybe should be doing while unbuilding this....
Oct 13 2019
FWIW, the adjustments I'm suggesting around tightening the logic can easily be in a follow-up patch if you like. I think generally the code LGTM and I'd just like us to pin down exactly what changes we expect to happen w/ the handles as much as possible to avoid subtle latent bugs creeping in and never getting noticed.
Oct 11 2019
(Tried to get this out last weekend, but was blocked by the Phab down time... Sorry about that ...)
Oct 5 2019
Adding Alina so she is aware of the change and can comment if she spots anything I'm missing...
Sep 11 2019
Sep 7 2019
LGTM to fix folks broken by this.
Sep 3 2019
This also makes sense to me why it would OOM. I suspect we're building a massive list, and at best we get lucky and they get de-duped later. At worst, this is actually fixing a serious functionality problem. We had the same thing w/ normal ASan before too. Since this pass doesn't need to be a function pass anyways, this seems totally fine. Thanks for tracking it down.
This idea isn't fundamentally flawed, its a good idea and something we've discussed many times.
Aug 28 2019
FWIW, LGTM. Thanks for all the work figuring out the right way to manage this at each step, and seeing it through, I think this is really great.
Aug 27 2019
Aug 20 2019
Thanks to Joerg for some useful discussion on IRC -- there was a concern I hadn't thought about that is exactly right: we somewhat want this pass to minimally disrupt things but also to be reasonably self contained.
Some nits below. LGTM with those fixed!
Aug 16 2019
This seems .... somewhat unfortunate. Adding Chris Bieneman to see if this is really the right thing to do or there are any other alternatives.
Aug 14 2019
As we discussed in person, we should refactor this so that when we enable MemorySSA we actually check the the loop passes in question mnanage to preserve it.
Also LGTM for cherrypick to the release branch.
Aug 13 2019
This approach is broken for another reason, which also motivated the LoopSink approach David mentioned.
This too LGTM, and again, thanks for driving this all the way through.
We should specifically call this out in release notes as well (before we forget) as a bunch of downstream people will discover it in LLVM 10.
Aug 12 2019
Aug 5 2019
One high level point that is at least worth clarifying, and maybe others will want to suggest a different approach:
Aug 3 2019
Generally, I do like the approach. Two high level comments:
Aug 1 2019
LGTM! Thanks for fixing this nasty bug (and sorry I wrote it).
LGTM with two nits addressed, thanks!
Jul 31 2019
Jul 11 2019
Just to make sure we're on the same page (and sorry I didn't jump in sooner)...
Sorry for the delay here.
LGTM, thanks so much for sticking through this, I know it was ... nontrivial!
Jul 2 2019
Pointing out the (serious) bug in this change below.
Jul 1 2019
The used thing still seems like there is an underlynig bug here. See below.
Since this review is ongoing, please revert the original patch to unblock people. There is no harm in reverting and landing with the fix once it is ready. =]
Jun 28 2019
Ok, now I've made a full pass through this. Mostly I think the first thing to do is tighten up the design around the core run function template and how reducers work with it. Documenting that design in detail will be really helpful I think.
(Also, really sorry, I mashed send button too soon, I'm still going through the code. Feel free to start on anything i posted, but sorry for the very random subset of comments)
I'd suggest enhancing the main description to include an overview of the code structure and organization to help reviewers follow the implementation design here. Think of it like a mini design doc for the *implementation* itself.
Jun 24 2019
Personally, I'd suggest the name llvm-reduce for the tool.
Jun 21 2019
FWIW, I think we can wait for a bug to be filed or report come in with some functional test case before we change any behavior here.
Jun 20 2019
Eh, this seems close enough now. I'd like a better approach for the x86 builtins, but no idea what it will end up being.
See inline comment, but I think we should just drop the testing of the function attribute bit here rather than adjusting the pipeline.
(Will likely need more eyes than just mine -- RPATH is mostly a mystery to me...)
Jun 19 2019
just a minor comment on one of these...
LGTM, again, really nice. Tiny tweak below.
Jun 18 2019
FWIW, this LGTM. We may want to tweak the behavior around flattening, but that can happen as a follow-up, and this seems to get us to a better state.
OMG, I'm so sorry, I had no idea that the tests would explode like that... Yeah, I don't think that's useful....
Jun 12 2019
LGTM. Bit annoying that we need to do this at O0, but fine...
Code change LGTM, but again, let's update the test to check both ways.
I understand the change to explicitly say -O2. I also understand the change to add an explicit -fno-experimental-new-pass-manager to a RUN line when we have another RUN line that explicitly uses -fexperiemntal-new-pass-manager.
Let's update the test to explicitly run w/ both PMs to make sure this keeps working. LGTM with that change.
Code change LGTM. Can you update at least one of the tests to explicitly run both PMs so that we'll notice if this breaks in some weird way? Feel free to submit with that change.
This really confused me. We shouldn't be seeing this kind of difference in the new PM.
This was a lot easier for me to understand too, thanks. Somewhat minor code changes below.
Jun 10 2019
I think this is somewhat the wrong approach.
I think this ultimately needs to be split up into smaller patches. A bunch of these things can be landed independently. Here is my first cut at things to split out, each one into its own patch.
I would just change this to have the module pass loop over the functions -- that seems like it'll be much cleaner.
Jun 8 2019
Any chance you can add a test that shows one of the problems where verifying MemorySSA fails because we get a "preserved" copy after a loop pass that doesn't actually preserve it?
Jun 6 2019
Joerg points out in IRC that we need control flow pruning to be symmetric w/ true and false.
(For posterity, this also should be in the implementation of SimplifyInstruction itself, not in the pass. The pass only ever calls that.)
I think this isn't quite right (if I've understood what it is doing correctly).
May 22 2019
Sorry I've been a bit slow to respond here...
May 18 2019
May 17 2019
Ok, I'm fine with this going in temporarily while we try to flip this flag acros sthe board (or figure out a heuristic that lets us get the best of both worlds). So, LGTM, but yeah, let's try to remove this too.
Eh, I'd like long term to have a way of testing this field in LLVM, but I think this is fine for now to unblock the Clang changes and other changes.
We should get folks to figure out why this regresses them, but making the two PMs behave the same seems fine for now.
One edge case left I think, but otherwise this LGTM. Happy for you to submit with the suggested change and a test case.
May 15 2019
I think you mentioned that there is already a test case that checks a global initialized with blockaddress? If I've mis-remembered, we should definitely add one and check that it *doesn't* inline (today). We can update it if/when we add support. If it is possible to add one that directly works w/ callbr, that'd be great.
LGTM as long as Eli is ok with the testing arriving after the fact.
May 10 2019
SLH bits LGTM.
May 7 2019
(Sorry for still more comments)
The file name of the test seems odd? How about vectorize-loops.c? I'd also make it a C test and put it in test/CodeGen instead of a C++ test.
May 6 2019
(To be explicit, this LGTM, just letting George mark it as accepted when he's happy too.)