similar to: questionabout loop rotation

Hi Stefanos, Thanks for your comments. I added both as reviewer. > One question though. Are you sure that this: > This helps with LICM when instructions inside a conditional is loop invariant  > is not achieved with the current LoopRotate pass? Because AFAIK, it does. Basically it inserts > a guard (that branches to the preheader) and then passes like LICM hoist invariant

Hi, Aditya, I took a look but I was hoping for a simpler example. And something that is more "usual". As Florian mentioned, these branches are on undefs. But thank you. Best, Stefanos Στις Δευ, 23 Μαρ 2020 στις 1:16 μ.μ., ο/η Florian Hahn < florian_hahn at apple.com> έγραψε: > > > > On Mar 21, 2020, at 23:13, Aditya K via llvm-dev < > llvm-dev at

Michael makes a great point about aliasing here and different indexing that accesses the same element! Another note: x = A[0][2] is fundamentally different depending on the type of `A`. If e.g. A was declared: int A[10][20], there's only _one_ load. A is a (and is treated as) a linear buffer, and GEPs only pinpoint the specific position of A[0][2] in this buffer (i.e. 0*10 + 2). But if A was

Hi Raphael, Thanks for the clarification. I note that in this case, I also think that Benson should preferably find a different project as that would probably be better for everybody. Best, Stefanos Baziotis On Wed, Mar 18, 2020, 12:24 Raphael “Teemperor” Isemann <teemperor at gmail.com> wrote: > Just to clarify my point about the “asking if there is already another > student

Hi Hal, > Documentation updates should also be reviewed. Of course, I meant that I'll open a patch in Phabricator. :) I didn't know about code-review patch, thanks. I'll defer the update of developer policy until the other patch is committed so we can have a clearer picture. Kind regards, Stefanos Στις Κυρ, 1 Μαρ 2020 στις 6:17 μ.μ., ο/η Finkel, Hal J. <hfinkel at anl.gov>

Hi Nick, What you said makes sense, but it's not called a call graph. :) You're essentially referring to what LoopInfo does which makes sense, but as I mentioned earlier, this is already done in the LoopInfo. Now, how much one will be able to use it in a LoopNestPass is another issue, which is certainly something that mentors could help you with. Best, Stefanos Στις Τρί, 17 Μαρ 2020

> > IMHO, you do. :) Lol, you have too much faith in me. On a more serious note, how do I know what issue can be solved in a reasonable amount of time/how do I search for one? > Please feel free to email me or Ettore if you encounter any blockers, or > have further questions. Hi Whitney, thanks for the video link and info. I was a bit busy today, but I will work tomorrow and get

Hi to both, > I'm not applying for GSoC but that's a hint if other students are applying to help them get started. Yes I agree, thanks for bringing up the topic. > On a more serious note, how do I know what issue can be solved in a reasonable amount of time/how do I search for one? Well, usually you don't. If you're lucky, someone will be able to provide you with some

On Sun, Apr 5, 2020 at 6:34 PM Stefanos Baziotis < stefanos.baziotis at gmail.com> wrote: > Hi Craig, > > > Adding a nuw to the add -8 is incorrect. > Yeah, I didn't mean to say it was correct. It was just an observation that > with nuw the optimization was happened and I asked if someone thought it > was somehow connected. > > > From the perspective of the

> Yes that's correct. Well, now that I saw the LoopNestAnalysis* files, they try to do sth similar. So, I hope it helped. > My idea was similar but using the call graph directly Personally I don't see how the call graph can help you, since well... it's a call graph. :) You care about loops in a specific function. What can help you is the Control-Flow graph, which is basically

Hi everyone, > I probably do not have the time to get a patch through. IMHO, you do. :) First of all, @Benson sorry but I'm not at all familiar with LLDB so I can't help there. Other than that, I'll also disappoint you both probably because I'm not that familiar with the creation of passes and the problem at hand. I'll try to help as I can. > Is there a specific

Hi Michael, Thanks for the reply. I've seen but have not used it. FWIW, the problem is not how to generate the runtime checks (although it'd be good if we can get it for free), but how to clean up the SCEVs. Does PSE do that ? Cheers, Stefanos Στις Δευ, 21 Σεπ 2020 στις 11:59 π.μ., ο/η Michael Kruse < llvmdev at meinersbur.de> έγραψε: > Have you looked into

Adding a nuw to the add -8 is incorrect. From the perspective of the unsigned math, -8 is treated a very large positive number. The input to the add is [8,13) and adding a large positive number to it wraps around past 0. So that is guaranteed unsigned wrap. On the other hand, a sub nuw 8 would be correct. ~Craig On Sun, Apr 5, 2020 at 3:27 PM Stefanos Baziotis via llvm-dev < llvm-dev at

Thanks to both! I'll update the docs. Best, Stefanos Στις Κυρ, 1 Μαρ 2020 στις 5:24 μ.μ., ο/η Florian Hahn < florian_hahn at apple.com> έγραψε: > Hi, > > > On 1 Mar 2020, at 14:44, Stefanos Baziotis via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > I recently was granted commit access, but I'm not really sure what is the > process. > The

Hi Rithik, I CC'd the 2 other mentors and hopefully you'll get answer. Sorry, but I don't know of any other way to help. :/ You may also try to contact them privately. Best, Stefanos Στις Τρί, 24 Μαρ 2020 στις 7:35 μ.μ., ο/η RITHIK SHARMA via llvm-dev < llvm-dev at lists.llvm.org> έγραψε: > Ping! > I'm bit concern about the approaching deadline next week, some

Hello, Following up on last week's LLVM-Dev meeting where we discussed MemorySSA related topics, I created the following google doc <https://docs.google.com/document/d/1-uEEZfmRdPThZlctOq9eXlmUaSSAAi8oKxhrPY_lpjk/edit#> with some of the meeting notes and planning for future meetings. For those who participated, please feel free to add items I may have missed into the document and cc

Np, good luck! :) - Stefanos Στις Τρί, 24 Μαρ 2020 στις 8:55 μ.μ., ο/η RITHIK SHARMA < rithiksh02 at gmail.com> έγραψε: > Many thanks, Stefanos! I really appreciate your help :) I heard from > Whitney. > > Best, > Rithik > > On Tue, 24 Mar 2020 at 23:08, Stefanos Baziotis < > stefanos.baziotis at gmail.com> wrote: > >> Hi Rithik, >> >> I

Hi, > I think the IR in both of your examples makes things harder for the compiler than expected from the original C source. Note that both versions are from clang with -O2. The first is with version 9.0 and the second is with the trunk. > but in the branch only %0 is used. Sinking the lshr too early made the analysis harder. Yes, exactly! That's what I figured too. > The version

> On Apr 5, 2020, at 22:20, Stefanos Baziotis <stefanos.baziotis at gmail.com> wrote: > > > Any idea about how the compiler could remove the lshr and use a add -16? > Actually, I just figured that doing this test is like solving this: > > 8 <= x/2 <= 13 > 16 <= x <= 26 > 0 <= x - 16 <= 10 => 0 <= x < 11 > The left part is know since

Indeed you're right, thanks! I need a nuw (which I have to invent, with a run-time check, since it doesn't exist in the original but anyway). Best, Stefanos Στις Παρ, 31 Ιουλ 2020 στις 12:36 μ.μ., ο/η Florian Hahn < florian_hahn at apple.com> έγραψε: > > > > On Jul 30, 2020, at 21:03, Stefanos Baziotis via llvm-dev < > llvm-dev at lists.llvm.org> wrote: >