similar to: [LLVMdev] Expressing ambiguous points-to info in AliasAnalysis::alias(...) results?

> > > The algorithm maintains a may-point-to graph. Unfortunately the > algorithm > > doesn't delete an "A-->B" edge when there's a strong update of "A" but > the > > value copied into "A" isn't a pointer. So the interpretation of "A" > having > > only one outbound edge (to "B") is a little

On Mon, Jun 15, 2015 at 1:43 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > > The AA algorithm uses dataflow analysis to monitor the possible > propagation > > of those values through the program code, and it represents those flows > by > > updates to the may-point-to graph. If at some code point CP, a > may-point-to > > graph vertex "B" has

On Thu, Aug 14, 2014 at 6:37 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > On Wed, Aug 13, 2014 at 8:35 PM, Jeremy Salwen <jeremysalwen at gmail.com> wrote: >> Hey Daniel, >> >> Thanks again for the help. I'm still a bit confused about the interface to >> the alias analysis. It seems like we are talking about different >> interfaces. >

> On 2015-Jun-13, at 09:12, David Blaikie <dblaikie at gmail.com> wrote: > > > > On Sat, Jun 13, 2015 at 12:52 AM, Chandler Carruth <chandlerc at gmail.com> wrote: > Greetings all, > > I'm working on refactoring the alias analysis layers to remove the usage of analysis groups and make the logic sharable between old and new pass managers, and I have a

On Mon, Jun 15, 2015 at 3:29 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > On Mon, Jun 15, 2015 at 10:33 AM, Christian Convey > <christian.convey at gmail.com> wrote: > > On Mon, Jun 15, 2015 at 11:02 AM, Daniel Berlin <dberlin at dberlin.org> > wrote: > Which paper are you using? > I'm mostly going from Robert Wilson's 1997 phd thesis,

Hi Hal, Thank you for your email, that makes a lot of sense to me. I am working on some tools to use memory profiling to speculatively replace memory loads and stores with value forwarding in hardware implementations. I'd like to compare the profiled data to static alias analysis, so it would be super useful if there was a way to answer the questions about aliasing across backedges that

Hi Daniel, Sorry for taking so long to respond. I spoke with a colleague more familiar with llvm who thought he could clear up my confusion, but we both came out of the conversation confused. I will try my best to explain the ambiguity. In an DAG, alias queries would be completely unambiguous. Every instruction would only be executed once, and every SSA value really would have a single static

Hi, I'm attempting to do some alias analysis & other memory inspection. I've written a pointless AliasAnalysis pass (that says everything must alias) to attempt to verify that my pass is getting picked up & run by opt. I run opt with: opt -load ~/Applications/llvm/lib/MustAA.so -must-aa -aa-eval -debug < trace0.ll I see my pass being initialized, but never being called (I see

Hey Daniel, Thanks again for the help. I'm still a bit confused about the interface to the alias analysis. It seems like we are talking about different interfaces. Has it changed from what the documentation says? As far as I can tell, the documentation takes a specific Value*, and no information about which dynamic execution it is talking about. When you say "Right. It's a

Hi Hal, Thanks. How about a symbol with two different immediate offsets - the Value* would be the same, right? I don't see how AliasAnalysis::Location would handle this... And BasicAliasAnalysis does if (V1 == V2) return MustAlias; , so I'm not sure how this would be done .. ? /Jonas > -----Original Message----- > From: Hal Finkel [mailto:hfinkel at anl.gov] > Sent:

On Mon, Jun 15, 2015 at 6:03 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > > From a personal perspective, I'm particularly interested in the maximum > > analytic precision each AA approach can take, almost without regard to > how > > much time or memory the computation takes to run. > > I'm wildly curious why. > One reason is that I'm simply

On Mon, Jun 15, 2015 at 9:31 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > >> I tried to find some subset i felt was worthwhile and where it was > >> okay, but gave up after a while. > > > > > > I'm not quite sure which things you're referring to in that statement. > > Would you mind clarifying? > > You can try to ameliorate it

On Mon, Jun 15, 2015 at 4:54 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > > I'm mostly going from Robert Wilson's 1997 phd thesis, although I'm > pretty > > sure I've seen a lot of the same ideas elsewhere as well. > > Yes, using summary/transfer functions has been tried a lot. > Note: the numbers in most of these phd thesis do *not* get born

On Mon, Jun 15, 2015 at 11:02 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > Points-to analysis on LLVM-IR itself is fine (see the current CFL-AA, > or the old deleted andersen's implementations), and giving may-alias > and no-alias results also works. Giving must-alias answers, however, > is difficult. > > In particular, i would not simply ignore some types of

On Apr 17, 2013, at 2:33 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> From: "Jonas Paulsson" <jonas.paulsson at ericsson.com> >> To: "Hal Finkel" <hfinkel at anl.gov> >> Cc: llvmdev at cs.uiuc.edu >> Sent: Wednesday, April 17, 2013 12:22:49 AM >> Subject: RE: [LLVMdev] alias analysis in backend

----- Original Message ----- > From: "Jonas Paulsson" <jonas.paulsson at ericsson.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: llvmdev at cs.uiuc.edu > Sent: Wednesday, April 17, 2013 12:22:49 AM > Subject: RE: [LLVMdev] alias analysis in backend > > Hi Hal, > > Thanks. How about a symbol with two different immediate offsets - the

Hello everyone, I am trying to find the alias between a store instruction's pointer operand and function arguments. This is the code, virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredTransitive<AliasAnalysis>(); AU.addPreserved<AliasAnalysis>(); } virtual bool runOnFunction(Function &F) { AliasAnalysis &AA =

> On 2015-Jun-15, at 16:29, Chandler Carruth <chandlerc at gmail.com> wrote: > > On Mon, Jun 15, 2015 at 3:56 PM Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote: > I like this colour: > > enum class AliasKind /* or AliasCategory? */ { > Null, > Unknown, > Partial, > Complete > }; > > So, the only

Hi again! Replying in chronological order: > On Thu, Jul 9, 2020 at 6:51 PM Shuai Wang <wangshuai901 at gmail.com > <mailto:wangshuai901 at gmail.com>> wrote: > > Hey Matt, > > That's awesome. Thank you very much for all the information and > clarification! Just a few follow up questions. Could you kindly shed > some lights on it? Thank

----- Original Message ----- > From: "Andrew Trick" <atrick at apple.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Jonas Paulsson" <jonas.paulsson at ericsson.com>, llvmdev at cs.uiuc.edu > Sent: Thursday, April 18, 2013 2:33:52 AM > Subject: Re: [LLVMdev] alias analysis in backend > > > On Apr 17, 2013, at 2:33 AM,