similar to: Full 'restrict' support in LLVM.

Hi all, ## Status: During the past weeks I have updated the restrict patches with various improvements: - the ScopedNoAliasAA now also works together with the new pass manager - the SLPVectorizer now works nice with the noalias support. - there were some issues with some of the options enabling/disabling full restrict. These have been fixed. - various smaller enhancements. Today, I rebased the

On 06/28/2018 10:59 AM, Hal Finkel wrote: > Hi, Jeroen, > > We should move these conversations to llvm-dev so that they don't get > missed and others can contribute. Can I cc the list? [+llvm-dev] - Jeroen consented. > > Doing this will mean that the logic for when to remove dead llvm.noalias > intrinsics will become more complicated. That might be worthwhile. So >

Hi, everyone, We had a great call last month, and progress is definitely being made on several fronts. The notes from our last call are available here: https://docs.google.com/document/d/1ybwEKDVtIbhIhK50qYtwKsL50K-NvB6LfuBsfepBZ9Y/edit#heading=h.vpxs8lkuxy79 and, also, pasted below. DOODLE POLL: As we discussed on our last call, I would like to schedule a regular call to discuss

Hi, We, IBM XL Fortran compiler team, is interested in representing Fortran alias information in LLVM IR. We use the XL Fortran frontend to emit LLVM IR that includes alias information to feed to the LLVM in order to create object files. For the Fortran alias representation in LLVM IR, we considered both TBAA and ScopeAlias/NoAlias metadata approaches, we think that the ScopeAlias/NoAlias

Johannes, Thanks, I have been following along some of the thread(s) and the phab reviews. The scope of this work is more encompassing than our current needs and I've looked at trying to carve a piece out. It's not clear to me what purpose the llvm.noalias intrinsic serves right now. Also, if a mem instruction has !noalias metadata, then it should not be aliased, but I must be missing

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Ok I think we have some common ground - CSE should choose the aliased pointer over the non-aliased one because we don't want the no-aliasing information to creep outwards from the inlined callsite. I'll put together a patch in the coming days and add y'all as reviewers so you get visibility. Cheers, -Neil. On Wed, Jan 22, 2020 at 4:47 PM Jeroen Dobbelaere < Jeroen.Dobbelaere at

Thanks, Jeroen, that really helps. A follow-up question, if you don't mind. What if we have code somewhat similar to your example in assign3() but it's in C++ and the pointer derived from x is stored in a class member field: class S { public: S(int *d): data(d) {} int *getData() { return data; } private: int *__restrict__ data; }; void assign4(int *pA, long N) { int

Hi Alexey, Adding llvm-ir bitcode support means adding/adapting the tags for LOAD/STORE instructions and adding the support for the noalias_sidechannel at the right places. I had a short attempt to implement it when preparing the public patches, but I am not familiar with that part of the llvm code. When I noticed that it would take a lot longer than anticipated, I postponed it. Also because it

At a high level, EarlyCSE should be intersecting the metadata of instructions that it combines. If it doesn't, and also doesn't drop the metadata, that seems like a bug, regardless of anything else. On 1/22/20 9:30 AM, Jeroen Dobbelaere wrote: Hi Neil, Hall, - as far as 'C' is concerned, this is input code is valid, as the pointers are not used to modify objects. - as far as

Hi, Nikita pointed me to an issue in the full restrict patches, related to name mangling used for llvm-ir functions (See [0, 3]). The problem is the following: Given: %0 = type { i32 } %1 = type { i32 } Creating an intrinsic @llvm.FOO that accepts 'a pointer to %0' cannot be distinguished from the intrinsic accepting 'a pointer to %1': ;For a %0* ptr0, %1* ptr1

We recently found an issue when using the full restrict implementation developed by Jeroen; it surfaces when compiling an obscure combination of std::valarray and std::indirect_array but I don't want to bore you with all the details. What it boils down to is this basic question about restrict: Given one restrict pointer based on another, should they never alias? As far as I understand the

I'm having an issue where SROA will throw away no-alias information on some loads after inlining, because the loads are derived from a store to an alloca which can be removed after inlining. The pointers that were originally stored into the alloca do *not *have any aliasing information - the only context that allowed me to assert aliasing was that the inlined-function guaranteed it to be so.

Hi Johannes et al, > -----Original Message----- > From: Doerfert, Johannes <jdoerfert at anl.gov> [..] > On 11/06, Jeroen Dobbelaere wrote: > > >From: Alexey Zhikhartsev > > [..] > > > We would love to see your patches merged as soon as possible, so I was > wondering: do you think the lack of bitcode support will prevent that from > happening? >

Great, thanks! Are you planning on just talking about these things with slides? Do we have other things to which we can link for people to read? -Hal Hal Finkel Lead, Compiler Technology and Programming Languages Leadership Computing Facility Argonne National Laboratory ________________________________ From: Tarique Islam <tislam at ca.ibm.com> Sent: Thursday, May 21, 2020 8:19:31 AM To:

Hi, I'm trying to abstract some special pointers with a class, like in the example program below: 1 #define __remote __attribute__((address_space(1))) 2 #include <stdint.h> 3 4 __remote int* A; 5 __remote int* B; 6 7 class RemotePtr { 8 private: 9 __remote int* __restrict a; 10 11 public: 12 RemotePtr(__remote int* a) : a(a) {} 13 14 __remote

Hi Alexey, >From: Alexey Zhikhartsev [..] > We would love to see your patches merged as soon as possible, so I was wondering: do you think the lack of bitcode support will prevent that from happening? Yes, I think that the lack of bitcode support will prevent it. During the Developers meeting, I also talked with Hal and Johannes. They had some extra remarks: - (1) the restrict

Hi Jeroen, Sorry, I missed that. I tried the patch, and this program: #include <stdint.h> #define __remote __attribute__((address_space(1))) __remote int* A; __remote int* B; void vec_add(__remote int* __restrict a, __remote int* __restrict b, int n) { #pragma unroll 4 for(int i=0; i<n; ++i) { a[i] += b[i]; } } int main(int argc, char** argv) {

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

> From: Eric Christopher > Subject: Re: [LLVMdev] How to associate extra comments to a > MachineInstruction ? > > Should be spelled like this yes? > > Asm->OutStreamer.AddComment("foo") > Asm->EmitFoo(); > > -eric That should work at the moment that you are emitting the instructions. But what would you do when you are manipulating a