similar to: [RFC] noalias intrinsic

I wanted to confirm that my understanding of the situation is correct. For background, I've been working have an optimizer pass for a research architecture which works best when there are large basic blocks and good alias analysis results. I first noticed the issue in rgbcmy01 from eembc-1.1, but have created a simpler test case which demonstrates the same issue which is unencumbered by the

----- Original Message ----- > From: "Raul Silvera" <rsilvera at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Chandler Carruth" <chandlerc at google.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Friday, November 14, 2014 10:34:39 AM > Subject: Re: [LLVMdev] Upcoming

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Thursday, November 13, 2014 7:02:58 PM > Subject: Re: [LLVMdev] Upcoming Changes/Additions to Scoped-NoAlias metadata > > > >

Thanks. This is probably one of the patches. So let me rephrase my questions: 1- What is the status of work to support block-local restrict-qualified pointers. 2- Does the set of patches with “llvm.noalias” label, more or less cover this work? Thanks Ehsan From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of 陳韋任 via llvm-dev Sent: Thursday, June 01, 2017 7:57 AM

----- Original Message ----- > From: "Alex Bradbury" <asb at asbradbury.org> > To: llvm-dev at lists.llvm.org > Cc: "Hal Finkel" <hfinkel at anl.gov> > Sent: Sunday, November 8, 2015 10:30:09 AM > Subject: Re: noalias parameter attribute not currently exploited by alias analysis? > > On 2 November 2015 at 20:20, Alex Bradbury <asb at

Hi everyone, As many of you might know, LLVM now has scoped noalias metadata (http://llvm.org/docs/LangRef.html#noalias-and-alias-scope-metadata) -- it allows us to preserve noalias function argument attributes when inlining, in addition to allowing frontends to add otherwise non-deducible aliasing properties to memory accesses. This currently works well, but needs a change and an intrinsic, as

On 11/13/2014 05:02 PM, Chandler Carruth wrote: > > This intrinsic needs to carry control dependencies (it cannot be > hoisted out of a loop, for example) -- in this sense it is very > much like @llvm.assume. And like @llvm.assume, we'll need to add > logic to various passes to ignore it as appropriate so that it > does not block optimizations

----- Original Message ----- > From: "Raul Silvera" <rsilvera at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Chandler Carruth" <chandlerc at google.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Monday, November 24, 2014 7:20:04 PM > Subject: Re: [LLVMdev] Upcoming Changes/Additions

----- Original Message ----- > From: "Raul Silvera" <rsilvera at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Chandler Carruth" <chandlerc at google.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Tuesday, November 18, 2014 9:09:40 PM > Subject: Re: [LLVMdev] Upcoming

----- Original Message ----- > From: "Raul Silvera" <rsilvera at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Chandler Carruth" <chandlerc at google.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Friday, November 14, 2014 12:15:51 PM > Subject: Re: [LLVMdev] Upcoming

Hi Daniel, On April 11, 2017 at 6:22:34 PM, Daniel Berlin (dberlin at dberlin.org) wrote: > Note: This is a generic problem with any situation where noalias exists but > the pointers are proven equal :) Yes. > TBAA, for example, has the same generic issue, we just drop the tbaa > metadata and declare it okay, even though it would have been UB at the > source level. Yes.  I

----- Original Message ----- > From: "Raul Silvera" <rsilvera at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Chandler Carruth" <chandlerc at google.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Tuesday, November 18, 2014 11:23:25 AM > Subject: Re: [LLVMdev] Upcoming

Hi, Looking at how noalias is defined: https://llvm.org/docs/LangRef.html#noalias-and-alias-scope-metadata "When evaluating an aliasing query, **if for some domain**, the set of scopes with that domain in one instruction’s alias.scope list is a subset of (or equal to) the set of scopes for that domain in another instruction’s noalias list, then the two memory accesses are assumed not to

Given some code: void func (float * restrict a, float *b) { for (int i =0; i < 100; ++i) { a[i] = b[i] + 1; } } float * aa; float * bb; int main() { func(aa, bb); return 0; } produces IR that has the llvm.noalias intrinsic along with the !noalias metadata:for both the load and store, however, AA returns MayAlias, I would expect a NoAlias? This is also an older version of llvm:

Thanks Nick! Can you just check sanity before I commit? (Or suggest a better name for the function...) -----Original Message----- From: Nick Lewycky [mailto:nicholas at mxc.ca] Sent: Sunday, May 26, 2013 09:54 To: Kuperstein, Michael M Cc: LLVMdev at cs.uiuc.edu Subject: Re: [LLVMdev] Mixing noalias and regular arguments Kuperstein, Michael M wrote: > Ping? Pong! Sorry for the slow review,

On Wed, Jun 12, 2013 at 7:28 PM, Guo, Xiaoyi <Xiaoyi.Guo at amd.com> wrote: > So fence only forces ordering of atomic instructions.**** > > ** ** > > Let me change my question then.**** > > ** ** > > If I have a target-specific intrinsic which forces ordering of ordinary > load/store instructions. Then should it also force ordering of load/stores > to

Ping? (Is there a code owner for AA, btw?) From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Kuperstein, Michael M Sent: Tuesday, May 21, 2013 18:23 To: LLVMdev at cs.uiuc.edu Cc: Raoux, Thomas F Subject: [LLVMdev] Mixing noalias and regular arguments Hi all, I'm trying to understand the semantics of noalias arguments, and I'm not entirely sure I

Hi all, I'm trying to understand the semantics of noalias arguments, and I'm not entirely sure I got it correctly. To the best of my understanding, if an argument is declared noalias, "This indicates that pointer values based on the argument do not alias pointer values which are not based on it" implies, among other things, that it cannot alias any other argument, even if that

On Tue, Apr 11, 2017 at 7:02 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > >> >> > It would require semantic changes to llvm ir to fix this to properly >> > express object lifetimes that is compatible with all the random babble >> > standards have written down :) >> > For now, the only sane solution IMHO, is to say that no alias implies

Kuperstein, Michael M wrote: > Ping? Pong! Sorry for the slow review, I had this patch starred but hadn't got around to it. Yes, the rationale and implementation are correct. > (Is there a code owner for AA, btw?) (It falls back on the more general code owner who is Chris Lattner in this case, "Everything not covered by someone else".) +/// isNoAliasArgument - Return true