similar to: [NewGVN] Plan for GVNPRE?

Hi Daniel, Thank you for your detailed reply, and thank you for working on GVNPRE. I’d more than happy to test/evaluate it with our benchmark once it is ready. Please let me know if you need any help. Thanks, Taewook From: Daniel Berlin <dberlin at dberlin.org> Date: Tuesday, April 4, 2017 at 6:13 PM To: Taewook Oh <twoh at fb.com> Cc: "llvm-dev at lists.llvm.org"

Hi Daniel, Got it. If that's the case, can I implement it under the guidance of your insights/prototype? I think I can spend more time on implementation. Thanks, Taewook ________________________________ From: Daniel Berlin <dberlin at dberlin.org> Sent: Tuesday, April 4, 2017 9:41:30 PM To: Taewook Oh Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] [NewGVN] Plan for GVNPRE? Of

Hi LLVMers, I am a PHD student in CS dept in UIUC, I am doing a project for Vikram's course, it is about PRE. I would like to know why you didn't choose SSAPRE in LLVM, since it seems to be more suitable for LLVM (it can operate directly on SSA form and avoid the conversion between SSA and bit-vector). Can anyone tell me the reason? Xuehai

On Fri, Apr 4, 2008 at 2:38 AM, Bill Wendling <isanbard at gmail.com> wrote: > On Apr 2, 2008, at 10:11 PM, Xuehai Qian wrote: > > Hi LLVMers, > > I am a PHD student in CS dept in UIUC, I am doing a project for > > Vikram's course, it is about PRE. I would like to know why you didn't > > choose SSAPRE in LLVM, since it seems to be more suitable for

i wish to develop llvm SSAPRE compiler optimization for my engineering academic project .for,that i have a sample c++ program and its .ll file.anyone have SSAPRE implementation in c++. if anyone have, please give me that implementation immediately. joseykollam at gmail.com josey @ 9895685353 elw technologies cochin -------------- next part -------------- An HTML attachment was scrubbed... URL:

On Fri, Nov 25, 2011 at 6:41 AM, josey's...JJ frm kollam nw @ calicut.... <joseykollam at gmail.com> wrote: > i wish to develop llvm SSAPRE compiler optimization for my engineering > academic project .for,that i have a sample c++ program and its .ll > file.anyone have SSAPRE implementation in c++. if anyone have, please give > me that implementation immediately. In the old

On Apr 4, 2008, at 4:51 PM, Daniel Berlin wrote: > On Fri, Apr 4, 2008 at 2:38 AM, Bill Wendling <isanbard at gmail.com> > wrote: >> On Apr 2, 2008, at 10:11 PM, Xuehai Qian wrote: >>> Hi LLVMers, >>> I am a PHD student in CS dept in UIUC, I am doing a project for >>> Vikram's course, it is about PRE. I would like to know why you >>>

It's basically ready to commit; the reviewers were fairly happy with it. It needs rebasing on top of NewGVN and any bugs that shakes out fixed, but that's about it. I want to get around to it soon-ish, but I've wanted that for a while! On Wed, 26 Apr 2017 at 16:50, Hongbin Zheng <etherzhhb at gmail.com> wrote: > Hi James, > > I have an ad-hoc solution in mind to solve

Hi Danny, Thanks for that :) However I've just updated the prototype patch to NewGVN and it didn't need any API changes - all I rely on is GVNExpression. Hongbin, I wanted to explain a little about what GVNSink can currently do, what it was designed for and hopefully how to make it handle your testcase. *Background* Common code sinking is more difficult to efficently do than one might

Is there a reason this is better than the modified algorithm created by Ferrante? It looks like yours has as bad a worst case time bound in reality. That is, the algorithm runs in O(sum of the size of all the dominance frontiers). http://www.cs.rice.edu/~keith/Embed/dom.pdf See figure 5. It will only touch nodes actually in the dominance frontier. This is what GCC uses. There are actually real

Hi Hal, In that case what is the best way to query whether there is a loop carried dependence between B[j] and A[j] at i-loop level? We were operating under the assumption of 'conservatively correct' behavior of alias analysis in the function scope? Thanks, Pankaj From: Finkel, Hal J. <hfinkel at anl.gov> Sent: Tuesday, March 17, 2020 11:50 AM To: Hiroshi Yamauchi <yamauchi at

There is a phi-node "%phi = phi i64 [%cast1, %if], [%cast2, %else]" in the common successor. The actual control flow is a bit more complex, but there is a common successor block, and %cast1 and %cast2 are the two values that the phi node in the common successor takes. Does the existence of the phi node affect optimization? Thanks, Taewook From: <mats.o.petersson at

It seems the GVNPRE pass has been removed from the main trunk, though it is present in the 2.6 release. From the llvm-commits archive, I found that it was removed  with this checkin: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090928/088214.html "remove the GVNPRE pass. It has been subsumed by the GVN pass." Does the GVN pass optimize all the partial redundancies

and by "right thing" i mean it can hoist if you want and it can prove it will not extend the live range. Note that VBE (very busy expressions) is a code size optimization only. It does not save time. On Tue, Feb 9, 2016 at 12:26 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > This GVN does not do that, this is correct. It is a very simple GVN. All > phi nodes are

Hi, I'm not able to answer your question. I'm wondering if you can create your own if it is just your own hobby project, or a project that you don't have to commit to the main repository. Creating DominatorFrontier seems to be expensive. However, if you are using bit-vector to represent a basic-block-set, I guess it can be done in linear time in practice. Following is the

Hello, I found that GVN doesn't promote identical sequence of instructions in if and else branch to their common predecessors. For example, for the following code snippet pred: … br i1 %cmp, label %if, label %else if: %incdec.ptr.1 = getelementptr inbounds i8, i8* %ptr, i64 1 %cast1 = ptrtoint i8* %incdec.ptr.1 to i64 … else: %incdec.ptr.2 = getelementptr inbounds i8, i8* %ptr,

Hi everybody. NewGVN was recently committed and a few minute ago I added a flag to enable the new experimental pass. For the brave soul, passing `-mllvm -enable-newgvn` should do the trick. We'll be happy to receive bug reports to analyze/fix, bonus point if they contain a synthetic/reduced testcase. Open a bug linked to https://llvm.org/bugs/show_bug.cgi?id=30995 would be probably best so

Hi all, Does anyone know how to recreate the DominanceFronter and PostDominanceFrontier structures using the API of the latest release? To my knowledge, these are needed to implement a PRE pass (as done in the past<https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_13/lib/Transforms/Scalar/PRE.cpp>), but they were removed a while ago for efficiency reasons. Is there a better way to

> > --- Algorithmic differences with the Machine Outliner ---- > > There was a lot of confusion on how exactly the algorithm I am > proposing differs from what is available in the Machine Outliner. The > similarities of the two outliners lie in the usage of a string matching > algorithm and candidate pruning. The first step in the algorithm is to > basically do

> On 6 Jan 2018, at 04:53, Daniel Berlin via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > > On Fri, Jan 5, 2018 at 8:39 PM, Andrew Kelley via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > Greetings, > > I just found a bug in NewGVN: https://bugs.llvm.org/show_bug.cgi?id=35839