similar to: [LLVMdev] Recent changes in -gmlt break sample profiling

On Fri Oct 24 2014 at 6:11:21 PM David Blaikie <dblaikie at gmail.com> wrote: > On Fri, Oct 24, 2014 at 2:48 PM, Diego Novillo <dnovillo at google.com> > wrote: > >> I'm not sure if this was intended, but it's going to be a problem for >> sample profiles. >> >> When we compile with -gmlt, the profiler expects to find the line number >>

On Fri Oct 24 2014 at 6:21:14 PM David Blaikie <dblaikie at gmail.com> wrote: > On Fri, Oct 24, 2014 at 3:16 PM, Diego Novillo <dnovillo at google.com> > wrote: > >> >> >> On Fri Oct 24 2014 at 6:11:21 PM David Blaikie <dblaikie at gmail.com> >> wrote: >> >>> On Fri, Oct 24, 2014 at 2:48 PM, Diego Novillo <dnovillo at

On Sun, Oct 26, 2014 at 4:59 PM, Eric Christopher <echristo at gmail.com> wrote: > On Fri, Oct 24, 2014 at 3:27 PM, Diego Novillo <dnovillo at google.com> > wrote: > > > > > > On Fri Oct 24 2014 at 6:21:14 PM David Blaikie <dblaikie at gmail.com> > wrote: > >> > >> On Fri, Oct 24, 2014 at 3:16 PM, Diego Novillo <dnovillo at

On Sun, Oct 26, 2014 at 3:47 PM, Jeremy Lakeman <Jeremy.Lakeman at gmail.com> wrote: > This sounds like a problem best solved by tracking source code movement via > your source control system. > If you know the commit of the code that produced the sample, you should be > able to use source control history / diffs to translate absolute line > numbers to the location where the

On Sun, Oct 26, 2014 at 7:23 PM, Xinliang David Li <xinliangli at gmail.com> wrote: > The fundamental questions we need to answer are the following: > FWIW, there was a longer discussion on the lists when the actual option was added. I'll try to relay my memory of that discussion, but you might need to track it down or involve some of the other people who participated in it.

On Fri, Oct 24, 2014 at 4:06 PM, Xinliang David Li <xinliangli at gmail.com> wrote: > Diego, > > I think sampleFDO needs to be designed in a way which can protect itself > from future breakage like this. The roots in the unnecessary dependency of > sample FDO on gmlt setting. It is totally reasonable to tune debug binary > size by changes like this. > > The right way

On Thu, Aug 28, 2014 at 11:51 AM, Alexey Samsonov <vonosmas at gmail.com> wrote: > This sounds great. Teaching backend about the -gmlt might help us in > another way: we might enforce full debug info generation in the frontend > for -fsanitize= flags, then rely on some parts of this debug info in > instrumentation passes and prune it before the actual object file >

In an effort to fix inlined information for backtraces under DWARF Fission in the absence of the split DWARF (.dwo) files, I'm planning on adding -gmlt-like data to the .o file, alongside the skeleton CU. Since that will involve teaching the LLVM about -gmlt (moreso than it already has - the debug info LLVM metadata already describes -gmlt for the purposes of omitting pubnames in that case) I

On Oct 30, 2013 7:25 PM, "Philip Reames" <listmail at philipreames.com> wrote: > > On 10/30/13 7:09 PM, Philip Reames wrote: >> >> David, Quentin - Thanks for the feedback. Responses inline. >> >> On 10/30/13 11:21 AM, David Blaikie wrote: >>> >>> Actually CCing Eric. >>> >>> >>> On Wed, Oct 30, 2013 at

On 10/30/13 7:09 PM, Philip Reames wrote: > David, Quentin - Thanks for the feedback. Responses inline. > > On 10/30/13 11:21 AM, David Blaikie wrote: >> Actually CCing Eric. >> >> >> On Wed, Oct 30, 2013 at 11:00 AM, Quentin Colombet >> <qcolombet at apple.com <mailto:qcolombet at apple.com>> wrote: >> >> Philip, >>

On Wed, Oct 30, 2013 at 8:58 PM, Eric Christopher <echristo at gmail.com>wrote: > > On Oct 30, 2013 7:25 PM, "Philip Reames" <listmail at philipreames.com> > wrote: > > > > On 10/30/13 7:09 PM, Philip Reames wrote: > >> > >> David, Quentin - Thanks for the feedback. Responses inline. > >> > >> On 10/30/13 11:21 AM,

Hi! Currently Clang "-g" flag emits full debug info, which is fine for debugging, but increases the binary size significantly. It may be useful to produce less debug info, that is still enough for collecting nice stack traces with file names and line numbers, but would introduce less overhead. Cary Coutant made a patch which does this for GCC (it didn't hit trunk yet) - reduces

On Apr 5, 2012, at 10:24 AM, Alexey Samsonov <samsonov at google.com> wrote: > Hi! > > Currently Clang "-g" flag emits full debug info, which is fine for debugging, but increases the binary size significantly. > It may be useful to produce less debug info, that is still enough for collecting nice stack traces with file names and line numbers, > but would introduce

Hello, Is it possible to somehow similar to how DWARF functions with assembly find out which line numbers in unoptimized code are associated with which bitcode instructions for the purpose of debugging compiler passes? I am curious about whether this is possible prior to writing some instrumentation passes for the purpose of debugging them. Thanks in advance, Carter. -------------- next part

David, Quentin - Thanks for the feedback. Responses inline. On 10/30/13 11:21 AM, David Blaikie wrote: > Actually CCing Eric. > > > On Wed, Oct 30, 2013 at 11:00 AM, Quentin Colombet > <qcolombet at apple.com <mailto:qcolombet at apple.com>> wrote: > > Philip, > > Thanks for the clarification. > > As far as I can tell, there is currently

Just working on some of the gmlt+fission debug info stuff and I came across a comment that might be relevant to reducing the number of distinct debugloc metadata nodes: "or some sub-optimal metadata that // isn't structurally identical (see: file path/name info from clang, which // includes the directory of the cpp file being built, even when the file name // is absolute (such as

Actually CCing Eric. On Wed, Oct 30, 2013 at 11:00 AM, Quentin Colombet <qcolombet at apple.com>wrote: > Philip, > > Thanks for the clarification. > > As far as I can tell, there is currently no way to preserve a full and > accurate stack trace while utilizing most of LLVM’s optimization abilities. > > The work on debug information may help you get the information

A few weeks ago, I announced the availability of a conversion tool that converts Linux Perf sample profiles to LLVM's sample profiler ( https://github.com/google/autofdo). I have now ported this tool to the LLVM tree, so it can be made available as part of LLVM. I've got a working version, but I still need to massage the code to use LLVM's own libraries (logging, flags, etc) and adapt

So, after many shenanigans, we finally have -gmlt-like inline summary debug info in .debug_info when using -gsplit-dwarf (see r221306). Hooray \o/ Testing this with asan, it seems to be working: Given a simple example of inlining failure: $ cat asan.cpp __attribute__((always_inline)) inline void func(int* i) { *i = 3; } int main() { func(nullptr); } The failures before this change: #0

On Wed, Aug 27, 2014 at 4:53 PM, Chandler Carruth <chandlerc at google.com> wrote: > > On Wed, Aug 27, 2014 at 4:40 PM, David Blaikie <dblaikie at gmail.com> wrote: > >> DW_AT_frame_base (the location of the frame pointer - is that needed for >> symbolication?) > > > I think this is used by libunwind style stack unwinders in conjunction > with