similar to: [LLVMdev] RFC - Making SamplePGO a module pass

damn... my english is not readable at all when I try to write fast... trying to make some clarification below, hopefully can make it more readable... On Tue, Nov 1, 2016 at 2:07 PM, Dehao Chen <dehao at google.com> wrote: > Oops... pressed the wrong button and sent out early... > > On Tue, Nov 1, 2016 at 2:01 PM, Dehao Chen <dehao at google.com> wrote: > >> If

If Hal's proposal is for SamplePGO purpose, let me clarify some design principles of SamplePGO. The profile for sample pgo uses source location as the key to map the execution count back to IR. This design is based on the principle that we do not want the profile to be tightly couple with compiler IR. Instead, profile is simple an attribute of the source code. We have been benefited a lot

The impact to debug_line is actually not small. I only implemented the part 1 (encoding duplication factor) for loop unrolling and loop vectorization. The debug_line size overhead for "-O2 -g1" binary of speccpu C/C++ benchmarks: 433.milc 23.59% 444.namd 6.25% 447.dealII 8.43% 450.soplex 2.41% 453.povray 5.40% 470.lbm 0.00% 482.sphinx3 7.10% 400.perlbench 2.77% 401.bzip2 9.62% 403.gcc

The large percentages are from those tiny benchmarks. If you look at omnetpp (0.52%), and xalanc (1.46%), the increase is small. To get a better average increase, you can sum up total debug_line size before and after and compute percentage accordingly. David On Thu, Oct 27, 2016 at 1:11 PM, Dehao Chen <dehao at google.com> wrote: > The impact to debug_line is actually not small. I only

----- Original Message ----- > From: "Hal Finkel via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Dehao Chen" <dehao at google.com> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Xinliang David Li" > <davidxl at google.com> > Sent: Tuesday, November 1, 2016 4:26:17 PM > Subject: Re: [llvm-dev] (RFC) Encoding code

Do you have an estimate of the debug_line size increase? I guess it will be small. David On Thu, Oct 27, 2016 at 11:39 AM, Dehao Chen <dehao at google.com> wrote: > Motivation: > Many optimizations duplicate code. E.g. loop unroller duplicates the loop > body, GVN duplicates computation, etc. The duplicated code will share the > same debug info with the original code. For

Is there prior art for this sort of thing (in GCC, for example) - I take it this isn't the first time this has come up as a problem for profile accuracy? (so it'd be helpful to know prior solutions to this (& if we're not doing whatever was done before, what it is about our situation that's different, etc), or why it hasn't been a problem, etc) On Thu, Oct 27, 2016 at

----- Original Message ----- > From: "Dehao Chen" <dehao at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Xinliang David Li" > <davidxl at google.com> > Sent: Tuesday, November 1, 2016 6:41:29 PM > Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in

----- Original Message ----- > From: "Dehao Chen" <dehao at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, "Xinliang David Li" > <davidxl at google.com> > Sent: Tuesday, November 1, 2016 8:24:30 PM > Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in

Discussed with Hal, Adrain and Paul offline at the llvm dev meeting today. * trip count is not enough for vectorization, there is runtime check that might go false, which can be reflected in profile that we may want to preserve. * simply recording these context-profile may cause problems to iterative-sample-pgo. i.e. when you find a loop's vectorized version no executed (due to runtime

In many cases, the line-table fussing to improve autoFDO/sample-PGO would also likely help the debugging experience for optimized code, certainly in cases where line attribution is inherently ambiguous. In those cases, I have no problem with Just Doing It. Something likely to pad the line table to benefit profiling without similarly benefiting debugging… that's probably worth inventing a

----- Original Message ----- > From: "Dehao Chen" <dehao at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Xinliang David Li" <davidxl at google.com>, "llvm-dev" > <llvm-dev at lists.llvm.org> > Sent: Tuesday, November 1, 2016 11:43:41 AM > Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor

Hi Dehao, This is definitely an important problem, thanks for writing this up! There is a related problem that I think we can address at the same time: When we multiversion code, for example when we use runtime checks to enable the creation of a vectorized loop while retaining the scalar loop, and then we collect profiling data, we should be able to recover the relative running time of the

Motivation: Many optimizations duplicate code. E.g. loop unroller duplicates the loop body, GVN duplicates computation, etc. The duplicated code will share the same debug info with the original code. For SamplePGO, the debug info is used to present the profile. Code duplication will affect profile accuracy. Taking loop unrolling for example: #1 foo(); #2 for (i = 0; i < N; i++) { #3 bar();

----- Original Message ----- > From: "Dehao Chen" <dehao at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Xinliang David Li" <davidxl at google.com>, "llvm-dev" > <llvm-dev at lists.llvm.org> > Sent: Tuesday, November 1, 2016 1:24:01 PM > Subject: Re: [llvm-dev] (RFC) Encoding code duplication factor in

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 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 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 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 >>

Guys, Just to clarify that with the current fix in SLM there is no need to wait for other issues to be fixed (minor issue). So you can move on with your patch. From: Agabaria, Mohammed Sent: Wednesday, June 07, 2017 15:24 To: Zaks, Ayal <ayal.zaks at intel.com>; Chandler Carruth <chandlerc at gmail.com>; Flamedoge <code.kchoi at gmail.com>; Dehao Chen <dehao at google.com>