similar to: [LLVMdev] dragonegg: switch from old TBAA format to the new struct-path aware TBAA format

Hi Manman, thanks for the heads up. I looked into what it would take to produce full struct TBAA metadata from the GCC aliasing info (GCC has aliasing info for struct types, in fact for any type), but it looks kind of tricky. The problem is the "offset" field, which doesn't exist in GCC. In GCC the aliasing information forms a DAG, with a node for each type, plus a special root

Hi, I am looking at the Type Based Alias Analysis and I am trying to understand why, from what I see, pointsToConstantMemory() never returns true. It seems that this information should come from the TBAA metadata, in which the Access Tag has an optional 4th field to specify this information. "Access tags are represented as MDNode s with either 3 or 4 operands. The first operand is an

After I run my script I save all my output e.g. write.table(d, file = "C:/PINEheight.txt) write.table(v, file = "C:/PINEvolume.txt) write.table(v, file = "C:/PINEdiameter.txt) write.table(v, file = "C:/PINEdensity.txt) and then I would like to run again with another tree and save again e.g write.table(d, file = "C:/POPULUSheight.txt) Is there anyhow I can define a

In Julia's use of LLVM, we were naming TBAA nodes with logic like this for LLVM 3.3: static MDNode *tbaa_make_child( const char *name, MDNode *parent, bool isConstant=false ) { MDNode *n = mbuilder->createTBAANode(name,parent,isConstant); n->setValueName( ValueName::Create(name, name+strlen(name))); return n; } The names would show up in dumps of the IR (e.g. "call

I was trying to add some stronger assertions in the verifier around !tbaa metadata when I ran into an ambiguity: I think the encoding of the metadata nodes are such that a given node can be interpreted as either a struct type node or a scalar tbaa node. I'd like a sanity check before I try to fix or work around this. Consider some IR that I got from running clang over a small C++ program:

Hi, I am encountering a problem that I do not know how to debug. I would greatly appreciate any guidance on this issue. On Windows when I run Lua test cases from JITed code I am getting following error: Unhandled exception at 0x00007FFCEEEAC500 (ntdll.dll) in lua.exe: 0xC0000028: An invalid or unaligned stack was encountered during an unwind operation. This is happening when the Lua code is

Hello, The motivation behind this proposal is to make it possible to propagate TBAA information through scalarizing transformations, such as SROA, that rewrite accesses to aggregates, e.g., memcpy() calls, into accesses to scalars, that is, load and store instructions. Currently, we decorate instructions that initialize and copy aggregates with !tbaa.struct tags that generally cannot be

Hi All, I'd like to propose some extensions to LLVM that will make it substantially faster at manipulating debug info, and will make the general annotation mechanisms in LLVM much richer: http://nondot.org/sabre/LLVMNotes/EmbeddedMetadata.txt Thoughts welcome, -Chris

Dear LLVMers, My name is Wei Wua graduate student at the Institute of Software,Chinese Academy of Science,Beijing,China.I'd like to paritcipate in the GSoC this year and I'm interest in the idea of Type-Based Alias Analysis implementation.I'm reading some papers about it for a few days and I want to know who is mentor of this sub-project? Thanks. -------------- next part

Hi, I have summit my proposal three days ago.It can be found here if you interest. http://socghop.appspot.com/gsoc/student_proposal/private/google/gsoc2010/wuwei_gucas/t126994250880 All comments are welcome. Details about my idea are not available now.I'll keep improving my proposal until the deadline. When I reading the docs<http://llvm.org/releases/2.6/docs/AliasAnalysis.html>

Hi, My proposal is here.(I've sent a link yesterday but it was a 'private' link.sorry for that mistake.) http://socghop.appspot.com/gsoc/I've sent a link yesterday but it was a 'private' link.sorry for that mistake.

Hi Yi, > Could anyone tell me how exactly do I use "Type Based Alias Analysis"? > > I compiled the C program with Clang, and verified that there is tbaa > metadata in the IR code. > > But then when I use "opt -tbaa input.c.bc -aa-eval" to check the results, > it always gives 100% may aliasing no matter what input. you need to run some optimizations on

On Dec 5, 2011, at 6:04 PM, Daniel Berlin wrote: > > Yet, aa-eval still says otherwise. The problem is with aa-eval. It collects all the pointer values in a function, and then just makes a bunch of raw pointer queries, rather than considering dereferences. TBAA tags are only attached to dereferences. So TBAA always has to say MayAlias for every aa-eval query. Dan

On Mon, Dec 5, 2011 at 11:08 PM, <liyi at cs.toronto.edu> wrote: >> On Dec 5, 2011, at 6:04 PM, Daniel Berlin wrote: >>> >>> Yet, aa-eval still says otherwise. >> >> The problem is with aa-eval. It collects all the pointer values in a >> function, and then just makes a bunch of raw pointer queries, rather than >> considering dereferences. TBAA

On Dec 5, 2011, at 9:32 PM, Daniel Berlin wrote: > On Mon, Dec 5, 2011 at 11:01 PM, Dan Gohman <gohman at apple.com> wrote: >> On Dec 5, 2011, at 6:04 PM, Daniel Berlin wrote: >>> >>> Yet, aa-eval still says otherwise. >> >> The problem is with aa-eval. It collects all the pointer values in a >> function, and then just makes a bunch of raw

Dan, Thanks for clarifying. This makes perfect sense. Gan >> Makes sense. In that case, it would give the expected answers if >> clang was enhanced to properly deal with similar/dissimilar pointer >> types, instead of giving all pointer types the "everything" tag :) > > No, you've confused pointer types with pointee types. That "any pointer"

On Wed, Jan 18, 2012 at 6:13 PM, Johan Tibell <johan.tibell at gmail.com> wrote: > Hi, > > While adding support for TBAA to GHC's LLVM backend, we ran into the > following issue: given a pointer that we know has certain aliasing > properties (e.g. it points to the stack, not the heap) we'd like to > >  * annotate all loads and stores to that pointer with a TBAA

On Wed, Jan 18, 2012 at 6:22 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Wed, Jan 18, 2012 at 6:13 PM, Johan Tibell <johan.tibell at gmail.com> wrote: >> While adding support for TBAA to GHC's LLVM backend, we ran into the >> following issue: given a pointer that we know has certain aliasing >> properties (e.g. it points to the stack, not the heap)

On Jan 30, 2012, at 4:04 PM, Hal Finkel wrote: > > Dan, where in the code is this done? I see a comment at the end of > BasicAliasAnalysis::aliasGEP regarding "protecting TBAA in the case of > dynamic indices into arrays of unions"; are you referring to that? Yes. And looking at the testcase, this appears to be the problem. Dan

Is this issue still active? It sounded as though Dan or Hal were looking at it but I havent seen an response. Should I resubmit as a bug so it gets tracked? thanks for your help On Tue, Jan 31, 2012 at 1:35 PM, Dan Gohman <gohman at apple.com> wrote: > On Jan 30, 2012, at 4:04 PM, Hal Finkel wrote: > > > > Dan, where in the code is this done? I see a comment at the end of