similar to: [LLVMdev] Static Profiling with LLVM

On Wed, Aug 13, 2008 at 7:00 PM, Sean Soria <sean.soria at gmail.com> wrote: > Is there currently a way to get static profiling information for a program > (e.g. an implementation of "Static Branch Frequency and Program Profile > Analysis" by Wu and Larus, or something more recent) using an LLVM pass? the profiling code, which has bitrotted considerably, supports random

Hello Kapil, I have implemented a static profiler for LLVM as a google summer of code project in 2009. I wrote it for the 2.4 branch, but the implementation never made into the tree. I have recently ported it to LLVM 2.8, but I haven't tested it. You can take a look at the code from: http://homepages.dcc.ufmg.br/~rimsa/tools/stprof-llvm.patch The implementation is based on Wu's

My god! I would love a branch predictor! It would simplify many aspects of my register allocator. Second, I am surprised it did not make it into the tree. Since more is being done with register allocation as a while "RegAllocBasic" was just put in, I hope this is looked at again. Do you have a working svn copy? Also, could you send me a copy/link to that '94 paper off the list

Thanks Andrei! I haven't read the paper. I would see whether this fulfills my requirements or whether I need to make any changes. --Kapil On Tue, Nov 2, 2010 at 12:43 PM, Andrei Alvares <logytech at gmail.com> wrote: > Hello Kapil, > > I have implemented a static profiler for LLVM as a google summer of > code project in 2009. I wrote it for the 2.4 branch, but the >

You said it was expensive, but if you had to put a big-o estimate on it, what would it be? -Thanks Jeff Kunkel On Tue, Nov 2, 2010 at 8:54 PM, Andrei Alvares <logytech at gmail.com> wrote: > Hello Jeff, > > On Tue, Nov 2, 2010 at 9:17 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > > My god! I would love a branch predictor! It would simplify many aspects > of >

Hello Jeff, On Tue, Nov 2, 2010 at 9:17 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > My god! I would love a branch predictor! It would simplify many aspects of > my register allocator. The branch predictor of the implementation is not as accurate as the one from the paper, but it is close enough. Unfortunately, the branch predictor is a very expensive pass, because it relies on

Hi Jeff, There is an algorithm to build the dominator tree that is O(n2), where n is the number of nodes on the control flow graph. I believe exists another that is linear, but I don't which one of them is implemented in LLVM. The problem is that the branch predictor requires post dominance information. None of the LLVM basic passes require post dominance information (AFAIK), hence it is

On Tue, Nov 2, 2010 at 12:28 AM, kapil anand <kapilanand2 at gmail.com> wrote: > Hi all, > > Does LLVM infrastructure contain implementation of any static profiling > algorithm apart from "Spill-Weight" calculation present in Live Intervals > class? The future work page does suggest implementation of some "static > profiling" algorithms to make an

Hi all, Does LLVM infrastructure contain implementation of any static profiling algorithm apart from "Spill-Weight" calculation present in Live Intervals class? The future work page does suggest implementation of some "static profiling" algorithms to make an educated guesses about the relative execution frequencies of various parts of the code. Thanks --Kapil --------------

It's done at the MachineFunctionPass level as far as I can tell ( http://llvm.org/doxygen/classllvm_1_1LiveIntervals.html). I'd like something at the FunctionPass level. On Tue, Aug 19, 2008 at 6:11 PM, Evan Cheng <evan.cheng at apple.com> wrote: > I am not sure what you mean. Live interval analysis is done at the > function level. > > Evan > > On Aug 19, 2008,

Ok. If it's at llvm ir level, it's very simple since everything is in SSA form. What are you trying to achieve though? Evan On Aug 19, 2008, at 6:51 PM, Sean Soria wrote: > It's done at the MachineFunctionPass level as far as I can tell (http://llvm.org/doxygen/classllvm_1_1LiveIntervals.html > ). I'd like something at the FunctionPass level. > > On Tue, Aug 19,

On 11/30/06, Andrew Lenharth <andrewl at lenharth.org> wrote: > The llvm_ostreams, which you take the address of go out of scope very > quickly, and are only stored by address in the bytecode writer, thus > the writers have a pointer to a stack allocated object they are to > write to. This crashes. The attached version leaks :-) It is a work around. If I understand correctly,

I just looked over your diff and it would seem to me that additional changes would be needed to be done to some of the LLVM-IR -> DAG stuff to make things fully functional (this could be a bit of supposition on my part since I do not fully understand all of the code). --- On Sun, 8/2/09, Andrew Lenharth <andrewl at lenharth.org> wrote: > From: Andrew Lenharth <andrewl at

On 2/15/08, Andrew Lenharth <andrewl at lenharth.org> wrote: > I'll take a hack at the front end support for > __sync_synchronize after this goes in. This is the gcc side of the patch. Index: gcc/llvm-convert.cpp =================================================================== --- gcc/llvm-convert.cpp (revision 46956) +++ gcc/llvm-convert.cpp (working copy) @@

On Sun, Aug 2, 2009 at 6:09 PM, Carter Cheng<carter_cheng at yahoo.com> wrote: > I just looked over your diff and it would seem to me that additional changes would be needed to be done to some of the LLVM-IR -> DAG stuff to make things fully functional (this could be a bit of supposition on my part since I do not fully understand all of the code). Code generation actually was

Hello all, I would like to participate in this year's Google Summer of Code and I am sending you a short description of my proposal. I have written the formal proposal already and if someone is interested I can send him the pdf. One of the open projects in the LLVM list is to enhance LLVM with static profiling capabilities. LLVM already provides a unified structure for writing pro

Attached is the target independent llvm.atomic.barrier support, as well as alpha and x86 (sse2) support. This matches Chandler's definitions, and the LangRef patch will just restore that. Non-sse2 barrier will be needed, I think it is "lock; mov %esp, %esp", but I'm not sure. Any objections? I'll take a hack at the front end support for __sync_synchronize after this

On Wed, Jul 14, 2010 at 10:54 AM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Wed, Jul 14, 2010 at 8:33 AM, Andrew Lenharth <andrewl at lenharth.org> wrote: >> On Wed, Jul 14, 2010 at 10:26 AM, Eli Friedman <eli.friedman at gmail.com> wrote: >>> On Wed, Jul 14, 2010 at 3:20 AM, Torvald Riegel >>> <torvald at se.inf.tu-dresden.de> wrote:

does that mean .o generated with gcc (.c -> .s and .s -> .o) will not contain llvm ir? i meant, final kernel bitcode ir arch independent and can be JIT with any arch-specific backend. Is it not the case? thanks, ashish On Sat, Sep 27, 2008 at 10:43 PM, Andrew Lenharth <andrewl at lenharth.org> wrote: > On Sat, Sep 27, 2008 at 8:08 PM, Ashish Bijlani > <ashish.bijlani at

On 7/9/07, Andrew Lenharth <andrewl at lenharth.org> wrote: > Poor alpha, no code examples or entries in your tables. But that said, it uses a load-locked, store-conditional and has various memory barriers which are sufficient to implement all your proposal. Andrew > On 7/9/07, Chandler Carruth <chandlerc at gmail.com> wrote: > > Hello, > > > > After a fair