similar to: [LLVMdev] LLVM instrumentation overhead

On 12/7/11 4:51 PM, Nipun Arora wrote: > Hi, > > I need to write a transform pass which instruments the target program to > output the name of each function executed, and the rdtsc counter along > with it. Doing this in LLVM is really straightforward. You simply iterate through all the functions in a module and add instructions to their entry basic blocks to do whatever it is

Hi John, Thanks for the detailed answer, this gives me a good starting point to look into. I was also wondering if you could give an idea (in terms of %ge) the overhead one can expect with such an instrumentation. I want something really lightweight and simple which can possible be applied to production systems, so overhead is a concern. Thanks Nipun On 12/09/2011 02:21 PM, John Criswell

Hi, Could anyone tell me how exactly can one convert a .bc file (bitcode file) to an executable in the native program. I was trying an instrumentation transform with the following workflow opt -insert-edge-profiling input.bc -o output.bc and then try and execute output.bc using lli output.bc however the program gives the following error : Program used external function

Hi, I was able to figure out this one, by checking out profile.pl. However, I am still interested in getting to know if there is anyway to compile from bitcode to a normal executable? Maybe I am missing something obvious... :P ? Thanks Nipun On Fri, Apr 1, 2011 at 1:34 PM, Nipun Arora <nipun2512 at gmail.com> wrote: > Hi, > > Could anyone tell me how exactly can one convert a

On 1/22/13 12:07 PM, Sahoo, Swarup Kumar wrote: > Hi John and Silky, > > I can see a copy of 'giri' slicing project branch here http://llvm.org/viewvc/llvm-project/giri/. Though it may be little older, it will work I think. You can look at the code to see how we do the instrumentation. The giri project is supposed to contain both the static slicing code and the dynamic

Hi, Could anyone point me to some simple examples/tutorials for writing instrumentation transform passes. Essentially adding instructions to basic blocks, such as print statements, load, add, store. I have tried going through profiling transforms, and was wondering if there is any better documented tutorial etc ? Thanks Nipun -------------- next part -------------- An HTML attachment was

On 1/13/13 11:06 PM, Criswell, John T wrote: > There is code that does this for older versions of LLVM. I believe it is in the giri project in the LLVM SVN repository. I can look into more details when I get back from vacation. Swarup may also be able to provide information on the giri code. I took a quick look, and the dynamic slicing code doesn't appear to be checked into the giri

Oh, OK. I didn't check the code. I think it only contains your flow tracking analysis code, isn't it. Our 'Giri' project was completely separate from it. Should we merge it with this or keep it as a separate project? -Swarup. ________________________________________ From: John Criswell [criswell at illinois.edu] Sent: Tuesday, January 22, 2013 12:12 PM To: Sahoo, Swarup Kumar Cc:

Hi John and Silky, I can see a copy of 'giri' slicing project branch here http://llvm.org/viewvc/llvm-project/giri/. Though it may be little older, it will work I think. You can look at the code to see how we do the instrumentation. Thanks, Swarup. ________________________________________ From: John Criswell [criswell at illinois.edu] Sent: Tuesday, January 22, 2013 10:29 AM To:

Hi, I am new to LLVM, and would like to write a dynamic profiler, say which prints out the load address of all the load instructions encountered in a program. >From what I could pick up, edge-profiler.cpp increments a counter dynamically which is somehow dumped onto llvmprof.out by profile.pl Could anyone explain me how this works? Can I instrument the code to dump out the load addresses or

There is code that does this for older versions of LLVM. I believe it is in the giri project in the LLVM SVN repository. I can look into more details when I get back from vacation. Swarup may also be able to provide information on the giri code. -- John T. ________________________________________ From: llvmdev-bounces at cs.uiuc.edu [llvmdev-bounces at cs.uiuc.edu] on behalf of Silky Arora

Hey Devang, Thanks for the assist, I'm trying to extract a signature which uniquely identifies a block of code.... this is required for a project I am doing. The no of data structures is one of the identifying features of this signature. Thanks Nipun On Fri, Oct 31, 2008 at 1:05 PM, Devang Patel <dpatel at apple.com> wrote: > Hi Nipun, > On Oct 30, 2008, at 9:31 PM, Nipun

Hi I am trying to count the no of datastructures and the type, say for example the number of arrays in a given code. Which pass would give me this info? And what do I need to use in it? Thanks for the help Cheers Nipun :) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20081031/ffceddee/attachment.html>

On 03/28/2011 12:15 PM, Nipun Arora wrote: > Hi, > > I have been trying to run the memdep analysis using opt with the > following command: opt -analyze -memdep <*.bc>. > However, I keep getting the following error: Pass::print not implemented > for pass: 'Memory Dependence Analysis' ! . > I get similar errors for a lot of the analyses passes, which seem as if

Right now I am writing passes just to look for arrays & structs I am trying to identify the array by parsing the memory description(use regex's) ex./ { [20 x i8], i32 } *- for a struct. is a structure with a character array of size 20 and an integer. I'm not sure if llvm provides an easier way to do this? The type id for most arrays comes out to be a pointer rather than an array, its

Hi, I read on the gentoo website http://en.gentoo-wiki.com/wiki/Llvm that glibc cannot be compiled using llvm because of some GNU extensions which LLVM does not support. Has there been any success in compiling glibc using LLVM so as to get the bytecode? We are looking to do whole program analysis to look at control flows including those in libc... we were hoping that we could get the control

Hi, I have been trying to run the memdep analysis using opt with the following command: opt -analyze -memdep <*.bc>. However, I keep getting the following error: Pass::print not implemented for pass: 'Memory Dependence Analysis' ! . I get similar errors for a lot of the analyses passes, which seem as if they should have a print out? Is there any other memory dependence analysis

Hi, How can one extract the operand of an instruction in an LLVM pass? Like I can get the opcode bt I'd like to get the operands as well Thanks Nipun -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20090211/3a073512/attachment.html>

Hi Nipun, On Oct 30, 2008, at 9:31 PM, Nipun Arora wrote: > Hi > > I am trying to count the no of datastructures and the type, say for > example the number of arrays in a given code. Which pass would give > me this info? And what do I need to use in it? What are you trying to achieve here with this information ? You can iterate over types to collect the info you need. For

How do you define a data structure for this purpose? Do you mean individual data types like structs or arrays? Or higher-level "logical" structures like lists, trees, or hash tables? The former is obviously easier but even the latter is possible, in some cases. --Vikram Associate Professor, Computer Science University of Illinois at Urbana-Champaign http://llvm.org/~vadve On