similar to: Possible bug of Alias Analysis?

> -----Original Message----- > From: meinersbur at googlemail.com [mailto:meinersbur at googlemail.com] On > Behalf Of Michael Kruse > Sent: Tuesday, October 17, 2017 3:26 PM > To: Song, Ruiling <ruiling.song at intel.com> > Cc: llvm at meinersbur.de; llvm-dev at lists.llvm.org > Subject: Re: Possible bug of Alias Analysis? > > 2017-10-17 8:45 GMT+02:00 Song,

Works for me On Thu, Jan 22, 2015 at 8:27 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > We should use graph edges, so we can do something better at set build time > :) > > > On Thu Jan 22 2015 at 5:20:46 PM George Burgess IV < > george.burgess.iv at gmail.com> wrote: > >> > Should we be added an edge from the inttoptr to all other pointer >>

So, I can make all these testcases work, but it's a little tricky (it involves tracking some things, like GEP byte range, and then checking bases and using getObjectSize, much like BasicAA does). Because i really don't want to put that much "not well tested" code in a bugfix, and honestly, i'm not sure we will catch any cases here that BasicAA does not, i've attached a

Updated testcases to have MayAlias/note issues as FIXME. On Tue Jan 20 2015 at 3:54:10 PM Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "Daniel Berlin" <dberlin at dberlin.org> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "Jiangning Liu" <Jiangning.Liu at arm.com>, "George

Without the patch is also returns the wrong answer for all of these, it just doesn't cause LICM to promote because it returns PartialAlias (which is still wrong). We return may-alias instead, and now suddenly it's happy to promote them. The broken noalias results exist both before and after my patch: ===== Alias Analysis Evaluator Report ===== 521 Total Alias Queries Performed

> -----Original Message----- > From: meinersbur at googlemail.com [mailto:meinersbur at googlemail.com] On > Behalf Of Michael Kruse > Sent: Wednesday, October 18, 2017 1:18 PM > To: Song, Ruiling <ruiling.song at intel.com> > Cc: Michael Kruse <llvm at meinersbur.de>; llvm-dev at lists.llvm.org > Subject: Re: Possible bug of Alias Analysis? > > 2017-10-18

No, i mean the actual store instruction looks like "store i16 %conv22, i16* getelementptr inbounds ([16 x i16]* @pA, i64 0, i64 12), align 2, !tbaa !1" Not that the pointer operand comes from a GEP, but it is a constantexpr, whose opcode is GEP. It sucks that there is such a complex thing to be handled as a store operand directly , but such is life ... CFL-AA *should* treat this

On Wed Jan 21 2015 at 12:30:50 PM Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "Daniel Berlin" <dberlin at dberlin.org> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "Jiangning Liu" <Jiangning.Liu at arm.com>, "George Burgess IV" < > george.burgess.iv at gmail.com>,

> Should we be added an edge from the inttoptr to all other pointer values? Is there a better way? We can add a special "Unknown" StratifiedAttr and query it before anything else, i.e: // in CFLAliasAnalysis::query, as the first potential return if (AttrsA[AttrUnknown] || AttrsB[AttrUnknown]) return MayAlias; The only *potential* issue with this approach would be that in the

Inline - George > On Jan 14, 2015, at 10:49 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > > > >> On Tue, Jan 13, 2015 at 11:26 PM, Nick Lewycky <nlewycky at google.com> wrote: >>> On 13 January 2015 at 22:11, Daniel Berlin <dberlin at dberlin.org> wrote: >>> This is caused by CFLAA returning PartialAlias for a query that BasicAA can

Oh, sorry, i didn't rebase it when i changed the fix, you would have had to apply the first on top of the second. Here is one against HEAD On Wed, Jan 14, 2015 at 12:32 PM, Ana Pazos <apazos at codeaurora.org> wrote: > Daniel, your patch does not apply cleanly. Are you on the tip? > > The code I see there is no line if (QueryResult == MayAlias|| QueryResult == PartialAlias)

(sorry for the wide distribution, but this impacts Clang users quite a bit) It's come up a few times in reviews of CFL-AA (a new alias analysis for LLVM), so I wanted to write down what I think the current state actually is for AA pass ordering, why, and how it should look eventually. I may have some bugs here, so please correct me if I miss anything. And I'd love thoughts about the end

On 13 January 2015 at 22:11, Daniel Berlin <dberlin at dberlin.org> wrote: > This is caused by CFLAA returning PartialAlias for a query that BasicAA > can prove is NoAlias. > One of them is wrong. Which one? I'm not sure from your description that this is a chaining issue. PartialAlias doesn't chain and isn't supposed to, it's a final answer just like NoAlias and

Inline George > On Jan 26, 2015, at 1:05 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > > George, given that, can you just build constexpr handling (it's not as easy as you think) as a separate funciton and have it use it in the right places? Will do. :) > FWIW, my current list of CFLAA issues is: > > 1. Unknown values (results from ptrtoint, incoming

----- Original Message ----- > From: "Daniel Berlin" <dberlin at dberlin.org> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Jiangning Liu" <Jiangning.Liu at arm.com>, "George Burgess IV" <george.burgess.iv at gmail.com>, "LLVM Developers > Mailing List" <llvmdev at cs.uiuc.edu>, "Nick Lewycky"

George, given that, can you just build constexpr handling (it's not as easy as you think) as a separate funciton and have it use it in the right places? FWIW, my current list of CFLAA issues is: 1. Unknown values (results from ptrtoint, incoming pointers, etc) are not treated as unknown. These should be done through graph edge (so that they can be one way, otherwise, you will unify

Yes. I've attached an updated patch that does the following: 1. Fixes the partialalias of globals/arguments 2. Enables partialalias for cases where nothing has been unified to a global/argument 3. Fixes that select was unifying the condition to the other pieces (the condition does not need to be processed :P). This was causing unnecessary aliasing. 4. Adds a regression test to

On Fri, Sep 21, 2012 at 3:08 PM, Welson Sun <welson.sun at gmail.com> wrote: > OK, with the restrict type qualifier, it is a little bit better: > > The IR's function signature becomes: > define void @foo(i32* noalias %a, i32* noalias %b, i32* noalias %c) nounwind > { > > Now the AA result: > Function: foo: 13 pointers, 0 call sites > NoAlias: i32* %a,

Hi, I am observing some incorrect behavior in basicaa, wherein two pointers that basicaa should determine to be MustAlias are ending up NoAlias - the other extreme :( I am blaming this on basicaa not handling inttoptr. Here is the relevant IR snippet. -------------------- %sunkaddr36 = ptrtoint %struct.BitParams* %bs to i32 %sunkaddr37 = add i32 %sunkaddr36, 16 %sunkaddr38 = inttoptr i32

Can you send me actual LLVM IR or a preprocessed source from using -E? I don't have a machine handy that has headers that target that arch. On Tue Jan 13 2015 at 4:33:29 PM Daniel Berlin <dberlin at dberlin.org> wrote: > Anything other than noalias or mustalias should be getting passed down the > stack, so either that is not happening or CFL aa is giving better answers > and