similar to: [LLVMdev] Range Analysis GSoC 2011 Proposal

Dear Douglas, Comments below. On 3/23/11 8:06 AM, Douglas do Couto Teixeira wrote: > Dear LLVM community, > > I would like to contribute to LLVM in the Google Summer of Code > project. My proposal is listed below. Please let me know your comments. > > > Adding Range Analysis to LLVM > > > > Abstract > > The objective of this work is patch our

On Wed, Mar 23, 2011 at 6:24 PM, John Criswell <criswell at illinois.edu> wrote: > > > On 3/23/11 8:06 AM, Douglas do Couto Teixeira wrote: > > > > the execution of a program. Thus, for each integer variable, a range > > analysis determines its lower and upper limits. A very simple range analysis > > > would, for instance, map each variable to the limits

Hi guys, I have an analysis that is able to answer questions like this: given an integer variable, what is the interval of values that this variable can assume during the program's execution? I want to integrate this analysis into LLVM and it seems LVI (Lazy Value Info) is the best place to do this kind of stuff. Can someone give some hints about what I have to do to integrate my analysis

Hi Douglas, On 21.02.2011 20:27, Douglas do Couto Teixeira wrote: > My work is not part of the LLVM mainline yet. But I would be happy to > contribute with the code of my range analysis implementation if it can help > you in something else. We were thinking of adding VRP to LLVM too, though we were mostly interested in Patterson's approach (i.e. not connected with SSI form). It

Hi, Andrey, sorry for the delay: I made a page with the code available for download: http://homepages.dcc.ufmg.br/~douglas/projects/RangeAnalysis/RangeAnalysis.html Feel free to get it, and if you need some help, I will be happy to tell you how to set the analysis up, in case the explanation in the page is not good. I also have a report describing the implementation here: (

Can't read your paper because the permission is not set. Chuck On 2/25/2011 12:16 PM, Douglas do Couto Teixeira wrote: > Hi, Andrey, > > sorry for the delay: I made a page with the code available for > download: > http://homepages.dcc.ufmg.br/~douglas/projects/RangeAnalysis/RangeAnalysis.html >

Hi guys, I am trying to figure out how to use your Lazy Value Info pass, but I am having some questions. First, it seems that the implementation contains infra-structure to deal with range intervals, but the main interface only gives the client information about which values are constants. Is this true? Second, reading the code I see that the ranges are being computed, but I could not tell if

Does llvm have a pass that minimizes the bitwidth of llvm instructions? For instance:   %8 = and i32 %7, 63 63 is 111111 in binary. So the 'and' instruction only requires 6 bits. We could rewrite the above code as:   %8 = trunc i32 %7 to i6   %9 = and i6 %8, 63 Since we only need the lower 6 bits we could also propagate this change backwards to reduce the bitwidth of prior

Hi! I'm a student who would like to participate on Google SOC for LLVM, and was thinking about what project to pick. I saw on the "Open projects" page that Value Range Propagation is not implemented and thought about doing it, based on a paper by Patterson (it's also used by GCC). But then I saw that last year someone did a Range Analysis pass that seems to do pretty much the

Hi, Gratian, I did that Summer of Code. I used a different algorithm than Patterson's. It is a constraint system by Su and Wagner, which is more modern, and has some advantages over older works. In particular, it is non-iterative. I found it very hard to compare it with Patterson's analysis, because there is not much description in that paper. However, there is another paper, by

----- Original Message ----- > From: "Daniel Berlin via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Joerg Sonnenberger" <joerg at britannica.bec.de>, "llvm-dev" > <llvm-dev at lists.llvm.org> > Sent: Thursday, January 14, 2016 10:38:10 AM > Subject: Re: [llvm-dev] High memory use and LVI/Correlated Value > Propagation > On

Hi John, thanks for your feedback. I'll try to answer your comments bellow. On Mon, Apr 2, 2012 at 10:59 AM, John Criswell <criswell at illinois.edu> wrote: > On 3/30/12 7:07 PM, Douglas do Couto Teixeira wrote: >> >> Hi guys, >> >> I'm an undergraduate computer science student and I've been working >> with pointer analysis this semester under

On Mon, Jan 24, 2011 at 3:01 PM, Nick Lewycky <nicholas at mxc.ca> wrote: > On 01/24/2011 04:41 AM, Douglas do Couto Teixeira wrote: > >> Hi, >> >> Nick, thanks for the reply. >> I still have a problem: I only need to "clone" an Instruction, changing >> its type. That is, I would like to keep all characteristics of the old >> Instruction

Yeah, that change is completely unrelated, that is about correctness, this is about optimization. I'm working on a proposal to just fix assume at some point to deal with the former issue. The problem with this testcase is that all the ways assume is propagate expect the variable in the assume to later be used. <This is the main way assume constants are propagated> bool

Hi Andrey, > On 21.02.2011 20:27, Douglas do Couto Teixeira wrote: >> My work is not part of the LLVM mainline yet. But I would be happy to >> contribute with the code of my range analysis implementation if it can help >> you in something else. > We were thinking of adding VRP to LLVM too, though we were mostly > interested in Patterson's approach (i.e. not

Maybe. It may not fix it directly because you never use %1 or %2 again. I haven't looked to see how good the lookup is. On Fri, Jun 10, 2016, 3:45 PM Josh Klontz <josh.klontz at gmail.com> wrote: > Thanks Daniel, with that knowledge I think I can at least work around the > issue in my frontend. > > Ignoring GVN for a second though, and just looking at Early CSE, it seems

Hi, Nick, thanks for the reply. I still have a problem: I only need to "clone" an Instruction, changing its type. That is, I would like to keep all characteristics of the old Instruction and create a new one only with a different type. I am trying create a new Instruction thus: %3 = add nsw i32 %1, %2 ; <i16> [#uses=2] //Old Instruction Value* Op0 = I->getOperand(0); Value*

Hi, guys, Thanks a lot for your help. As you know, I am trying to implement something to change the types of the instructions. And I chose the trunc's approach because it seems be simple. But I still have some problems and questions. Would be great if you can help me. I have used the results of my range analysis implementation to change the intermediate representation. I am using

Hi everybody, I saw that there are some instructions in the programs in which the flag nsw or nuw is placed. I wonder what rules does LLVM follows to put these flags in some instructions. Best, Douglas -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110112/e696af22/attachment.html>

On 1/24/11 12:05 PM, Douglas do Couto Teixeira wrote: > > > On Mon, Jan 24, 2011 at 3:01 PM, Nick Lewycky <nicholas at mxc.ca > <mailto:nicholas at mxc.ca>> wrote: > > On 01/24/2011 04:41 AM, Douglas do Couto Teixeira wrote: > > Hi, > > Nick, thanks for the reply. > I still have a problem: I only need to "clone" an