similar to: [LLVMdev] attributes helper functions - please review

Dear LLVM developers, Our team has developed an LLVM-based protection mechanism that (i) prevents control-flow hijack attacks enabled by memory corruption errors and (ii) has very low performance overhead. We would like to contribute the implementation to LLVM. We presented this work at the OSDI 2014 conference, at several software companies, and several US universities. We received positive

Using the New Attributes Classes Attributes in LLVM have changed in some fundamental ways. It was necessary to do this to support expanding the attributes to encompass more than a handful of attributes --- e.g. command line options. The old way of handling attributes consisted of representing them as a bit mask of values. This bit mask was stored in a "list" structure that was reference

Very nice! Could we get this write-up added to the sphinx docs? On Sat, Feb 9, 2013 at 11:41 AM, Bill Wendling <wendling at apple.com> wrote: > Using the New Attributes Classes > > Attributes in LLVM have changed in some fundamental ways. It was necessary > to do > this to support expanding the attributes to encompass more than a handful > of >

Hi all, Is there an efficient way to construct an AttributeSet for the purpose of constructing a Function? The only (public) way I've found to designate the parameter index of attributes is via the addAttribute methods of the Function class or the AttributeSet. This is quite inefficient as a new AttributeSet is constructed every time. In fact, it takes the bulk of the time my codegen

Hello. I'm writing an LLVM pass that is working on LLVM IR. To my surprise the following LLVM pass code generates optimized code - it does copy propagation on it. Value *vecShuffleOnePtr = Builder.CreateGEP(ptr_B, vecShuffleOne, "VectorGep"); ... packed_gather_params.push_back(vecShuffleOnePtr); CallInst *callGather =

This addition converts strlen() calls to strnlen() when the result is compared to a constant. For example, the following: strlen(s) < 5 Becomes: strnlen(s, 5) < 5 That way, we don't have to walk through the entire string. There is the added overhead of maintaining a counter when using strnlen(), but I thought I'd start with the general case. It may make sense to only use this

> On Dec 30, 2016, at 3:03 PM, Alex Susu via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hello. > I'm writing an LLVM pass that is working on LLVM IR. > To my surprise the following LLVM pass code generates optimized code - it does copy propagation on it. It does *constant* propagation to be exact. > Value *vecShuffleOnePtr = Builder.CreateGEP(ptr_B,

On 08/24/2017 09:40 AM, Tim Northover wrote: > On 17 August 2017 at 15:15, Rodney M. Bates via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> For an indirect call, i.e., on a function whose address is runtime variable, >> I can't find any place/way to attach this attribute. LLVMAddAttribute >> won't take a type. > > In the C++ API you'd add the

I did a RelWithDebInfo + asserts build of LLVM just now and, when running "make check" under Valgrind, am seeing a lot of uses of uninitialized memory like the one below. Anyone know offhand what's likely to be the root cause? Unfortunately a Debug build doesn't give these errors. Thanks, John FAIL: LLVM :: Analysis/BasicAA/pr18573.ll (2093 of 18733)

Well, it looks like almost all of the problems go away when I build using trunk instead of 3.9. So, that was scary but I'm going to forget it ever happened. >8000 test cases failed under Valgrind!! John On 11/20/2016 03:03 AM, Sanjoy Das via llvm-dev wrote: > Hi John, > > This is probably somewhat of a stretch, but since the problem does not > happen with a Debug build,

+Bill who worked on the attribute change On Mon, Mar 25, 2013 at 9:15 AM, Harris BAKIRAS <h.bakiras at gmail.com> wrote: > Hi everyone, > > We are using the llvm2cpp feature of LLVM in the VMKit project and there are > some issues that I would like to point out. > > I made a tiny reproducible example here, to be clear: > > echo "int main() { return 0; };"

Hi everyone, We are using the llvm2cpp feature of LLVM in the VMKit project and there are some issues that I would like to point out. I made a tiny reproducible example here, to be clear: echo "int main() { return 0; };" > test.c && clang test.c -emit-llvm -c -o - | llc -march=cpp -cppgen=function -cppfor=main -o - This command is supposed to generate the C++ code to

> On Jul 14, 2015, at 4:48 PM, Reid Kleckner <rnk at google.com> wrote: > > This sounds more like a use case for metadata. Can we attach metadata to function arguments, or does that not work currently? We can’t, no. I have an out of tree patch which allows metadata in AttributeSets. This would also potentially also work here. However, depending on the number of unique

On Tue, Jul 14, 2015 at 9:01 PM Philip Reames <listmail at philipreames.com> wrote: > On 07/14/2015 05:07 PM, Pete Cooper wrote: > > > On Jul 14, 2015, at 4:48 PM, Reid Kleckner <rnk at google.com> wrote: > > This sounds more like a use case for metadata. Can we attach metadata to > function arguments, or does that not work currently? > > We can’t, no.

On 04/01/2013 12:31 PM, Chandler Carruth wrote: > On Thu, Mar 28, 2013 at 12:22 PM, Nadav Rotem <nrotem at apple.com > <mailto:nrotem at apple.com>> wrote: > > IMHO the right way to handle target function attributes is to > re-initialize the target machine and TTI for every function (if > the attributes changed). Do you have another solution in mind ?

On Jan 30, 2013, at 8:20 PM, Christian Schafmeister <chris.schaf at verizon.net> wrote: > > Hi, > > I recently upgraded to the latest LLVM build and encountered a problem where the API for Argument::addAttr has changed. > > Previously it was Argument::addAttr(Attribute A) and I was able to work with this. > > The latest build has changed the method addAttr so

Hi, I recently upgraded to the latest LLVM build and encountered a problem where the API for Argument::addAttr has changed. Previously it was Argument::addAttr(Attribute A) and I was able to work with this. The latest build has changed the method addAttr so that it requires an AttributeSet argument (Argument::addAttr(AttributeSet AS). I'm not sure how to adjust to this change. The

On Nov 20, 2012, at 11:03 AM, Meador Inge <meadori at codesourcery.com> wrote: > On Nov 13, 2012, at 12:20 AM, Bill Wendling wrote: > >> IR Changes >> ---------- >> >> The attributes will be specified within the IR. This allows us to generate code >> that the user wants. This also has the advantage that it will no longer be >> necessary to specify

LLVM's Attribute APIs need an overhaul. Current problems ================ First, testing for an attribute on an Argument is slow. llvm::AttributeSet::getAttributes(int) consumed 2% of cycles while optimizing llc during LTO. Our mid-level optimizations are constantly asking if a given argument has some attribute (nonnull, dereferencable, etc), and this is currently linear in the size of the

Hi, On 13 Jul 2015, at 15:59, Hal Finkel <hfinkel at anl.gov<mailto:hfinkel at anl.gov>> wrote: ----- Original Message ----- From: "Artur Pilipenko" <apilipenko at azulsystems.com<mailto:apilipenko at azulsystems.com>> To: llvmdev at cs.uiuc.edu<mailto:llvmdev at cs.uiuc.edu> Cc: "Hal Finkel" <hfinkel at anl.gov<mailto:hfinkel at