search for: attributor

Hi Farad, > I tried to do this for the NoUnwind attribute Hmm, I don't have experience with this attribute but it seems like a good starting point since it doesn't do much. First of all, be sure that you run with: opt -passes=attributor -attributor-disable=false This uses the new pass manager which is another discussion. Now, to the point: If you open nounwind.ll, it has a bunch of test cases and I don't think it's a good idea to run Attributor in all of them at first. So, break it into individual tests. First of all, note...

Hi Fahad, > > Improve dynamic memory related capabilities of Attributor. For example > Improve HeapToStackConversions. Maybe such deductions can help safety > (dis)provers. For example, can we improve the use-after-free bug detection > using some attributes? > Stefan should know more about H2S. Regarding the use-after-free, I don't > think there'...

...e written small toy inter-procedural dataflow analysis (like taint analysis, reaching definitions, etc) for JAVA programs using SOOT tool *[5].* I am familiar with the theory of inter-procedural analysis (I’ve read some chapters of [1], [2] and [3] for this). I am trying to understand the LLVM’s Attributor framework. I am interested in these 3 aspects: 1. How Attributor can help for standard inter-procedural and intra-procedural analysis passes of LLVm. I’ve seen the tutorial [4]. I would like to discuss ways of improving other optimization passes similarly (or some examples which ha...

[AMD Official Use Only - Internal Distribution Only] Hi , There seems to be some issue with attributor, exactly in File Attributor.cpp, Function Attributor::rewriteFunctionSignatures(), Line No: 1600 (approrimate). The llvm source code at above address is as follows: // Eliminate the instructions *after* we visited all of them. for (auto &CallSitePair : CallSitePairs) { CallBa...

...er header of Internal and Official use only. > > Thanks > M Suresh > > From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Mani, Suresh via llvm-dev > Sent: Friday, May 15, 2020 4:37 PM > To: llvm-dev at lists.llvm.org > Subject: [llvm-dev] Issues with new Attributor (replaceAllUses fails with type mismatch) > > [CAUTION: External Email] > > [AMD Official Use Only - Internal Distribution Only] > > Hi , > > There seems to be some issue with attributor, exactly in File Attributor.cpp, Function Attributor::rewriteFunctionSignatures(), Li...

Hi all, What's the current status of Attributor? How far is it from being enabled by default? Thanks, Alexey -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200828/0abd04c3/attachment.html>

On 03/16, Fahad Nayyar wrote: > I can see that Johanned have put up some issues for GSOC aspirants. I think > that [2] <https://github.com/llvm/llvm-project/issues/179> ([Attributor] > Cleanup and upstream `Attribute::MaxObjectSize`) will be a very good issue > for me, It seems doable and I can get familiar with the whole process of > writing a patch for an issue. How should I indicate to the community that I > have started working towards this issue (should I comm...

Thank you Hal and Stefan! Bug report is filed: https://bugs.llvm.org/show_bug.cgi?id=46717 And Stefan, I think 'attributor' is a really nice pass, and can infer more precise and useful attributes, which may give more opportunities for optimization. But we shouldn't depend on 'attributor' to correct wrong function attributes, because we cannot run 'attributor' after every pass, right? Thanks, Fa...

...a llvm-dev wrote: > > On 7/14/20 11:28 AM, Fangqing Du wrote: >> Thank you Hal and Stefan! >> >> Bug report is filed: https://bugs.llvm.org/show_bug.cgi?id=46717 >> <https://bugs.llvm.org/show_bug.cgi?id=46717> >> >> And Stefan, >> I think 'attributor' is a really nice pass, and can infer more >> precise and useful attributes, which may give more opportunities for >> optimization. >> But we shouldn't depend on 'attributor' to correct wrong function >> attributes, because we cannot run 'attributor...

...parate address space. Is there a preferable environment? In any case, I am thinking of containerizing the build, so OS X system paths don't interfere with include paths - have you received feedback from other developers on whether the include paths interfere with OS X LLVM system build? 2. The attributor pass refactoring gives some specific direction as a startup project - so that's great. Let me study this pass and I will get back to you with more questions. 3. Yes, I will stick to the style guide (Baaaah...Stanford is strict on code styling and so are you guys :)) for sure. On Thu, Mar 26,...

...e `readonly` and `readnone`. Readonly > implies no side effects (no writes), and readnone implies no memory > dependencies at all. The return value is a pure function of the arguments. > Two calls with the same arguments can be folded together. > > There are a couple of passes (Attributor, FunctionAttrs, I'm not > up-to-date) that will infer these attributes if they can see a precise > definition of the function body. Learning anything interesting usually > requires expanding the scope of analysis with LTO, so these passes can look > across translation unit boun...

I am a grad CS student at Stanford and wanted to engage with EJ Park, Giorgis Georgakoudis, Johannes Doerfert to further develop the Machine Learning and Compiler Optimization concept. My background is in machine learning, cluster computing, distributed systems etc. I am a good C/C++ developer and have a strong background in algorithms and data structure. I am also taking an advanced compiler

...er developers on whether the include paths > > interfere with OS X LLVM system build? > > > Setup sounds good. > > I have never used OS X but people do and I would expect it to be OK. > > I don't think you need to worry about this right now. > > > > 2. The attributor pass refactoring gives some specific direction as a > > startup project - so that's great. Let me study this pass and I will get > > back to you with more questions. > > Sure. > > > > 3. Yes, I will stick to the style guide (Baaaah...Stanford is strict on > >...

Hi Johannes. My name is Hideto Ueno. I’m interested in working on GSoC project, “Improve (function) attribute inference”. As far as I see [0] and related patches, you have already implemented algorithms for many of the deducible function attributes with the new framework “Attributor”. I doubt whether there is still room for improvement as a GSoC project. If there is, let me know. Thanks. Hideto Ueno [0] http://lists.llvm.org/pipermail/llvm-dev/2019-April/131483.html -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pi...

...ti-step are missing in the 1pass, and 67 from 1pass are missing in the multistep. These appear to be opt flags, since they cause an error when trying to use them with clang (e.g. -x86-fixup-LEAs) and when used with opt causes a crash with stack dump and request to submit a bug report. Others like -attributor appear to work with opt. I'm currently blindly trying to add the 67 different flags to the opt step to see which work, and hopefully that subset will produce the same result as clang -O3. It seems like there must be an easier / more exact way of getting the opt -O3 multi-step to match the cla...

Hi all, Let's see an example (from Alexandre Isoard) first: **************************************************************************************** ; RUN: opt -ipsccp -deadargelim -licm -O2 -S < %s @g = internal global i32 0 ; Function Attrs: argmemonly define internal void @foo(i32* nonnull dereferenceable(4) %arg, i32 %val) #0 { entry: store i32 %val, i32* %arg ret void } define

...gt;> > >> > >> Setup sounds good. > >> > >> I have never used OS X but people do and I would expect it to be OK. > >> > >> I don't think you need to worry about this right now. > >> > >> > >>> 2. The attributor pass refactoring gives some specific direction as a > >>> startup project - so that's great. Let me study this pass and I > will get > >>> back to you with more questions. > >> > >> Sure. > >> > >> > >>> 3. Yes, I...

Hi All I am writing a pass which requires checking dependences, and am having trouble dealing with function calls. Specifically, I want to be able to know when a called function does not have any side effects (e.g. math library functions like sqrt), and was wondering if there are attributes that specify this behavior (I know there is the ‘noread’ attribute but wasn’t sure if there’s something

...re missing in the >> multistep. >> >> These appear to be opt flags, since they cause an error when trying to >> use them with clang (e.g. -x86-fixup-LEAs) and when used with opt causes >> a crash with stack dump and request to submit a bug report. Others like >> -attributor appear to work with opt. >> >> I'm currently blindly trying to add the 67 different flags to the opt >> step to see which work, and hopefully that subset will produce the same >> result as clang -O3. >> >> It seems like there must be an easier / more exact wa...

...e "used" on the call site though*. And you can place it on the callee (f) if it was internal or you copy it to make it internal. So the optimization potential is still there, even if it is a little trickier. * FWIW, one-level of selective context sensitive propagaton is planned for the Attributor. > we would say the return value of f(null, 1) is poison. But if you > inline the function you get UB. Inlining has to continue to be correct > without exceptions. The attributes will just never represent the possible UB exhaustively. I mean, inlining is still correct and the UB that...