Re: [eigen] Significant perf regression probably due to bug 363 patches

[Benoit Jacob <jacob.benoit.1@xxxxxxxxx>]

I've uploaded a patch on Bug 363, here's the review link:

http://eigen.tuxfamily.org/bz/page.cgi?id=splinter.html&bug=363&attachment=225

Benoit

2011/11/6 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
> OK, now I can reproduce the big 50% perf regression that you observed,
> it's just that before I was looking only at subtests instead of the
> final results.
>
> The problem is just that, despite the inline keyword, the
> check_rows_cols_for_overflow function is not getting inlined. Adding
> __attribute__((always_inline)) on it fixes it. patch coming up.
>
> Benoit
>
> 2011/11/6 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
>> Thanks, I can reproduce a 10% performance decrease on linux x86_64,
>> g++ 4.6.1, core i7.
>>
>> investigating.
>>
>> Benoit
>>
>> 2011/11/6 Eamon Nerbonne <eamon@xxxxxxxxxxxx>:
>>> Whoops, that's what you get for copyNpaste coding; the ClassDiagram function
>>> was never intended to be called for scenario's other than in 2D (as the name
>>> might suggest...).  The perf degradation I previously mentioned was in the
>>> 2d case (and that was a different benchmark anyhow), so this error doesn't
>>> invalidate those results (the code works @ 2d).  I've updated the function
>>> to just ignore excess dimensions.  The Eigen/EigenValues vs.
>>> Eigen/Eigenvalues issue is due to the fact that I'm running these tests on
>>> windows where paths are case insensitive.
>>>
>>>
>>> While I was changing the benchmark anyhow, I've added an option to declare
>>> matrix sizes as Dynamic and size matrices at run-time (the code wasn't
>>> changed to avoid temporaries, so that'll be much slower due to memory
>>> management).  I also changed the code to scale the number of timings rather
>>> than the workload per timing as dimensionality rises so that timings should
>>> be comparable between different dimensions (of course, the task is harder at
>>> higher dimensionality).
>>>
>>>
>>> sample compile then:
>>> g++ GgmLvqBench.cpp -std=c++0x  -DNDEBUG  -DLVQFLOAT=double -DLVQDIM=2 -O3
>>> -march=native
>>> and perhaps add -DLVQDYNAMIC or -DEIGEN_DONT_VECTORIZE
>>>
>>> At changeset 4284 (25822e1ace8d) update the decomposition catalogue
>>> EigenBenchNV on GCC with 2(2) dimensions of doubles: 0.168s 189KB
>>> EigenBenchV on GCC with 2(2) dimensions of doubles: 0.148s 268KB
>>> EigenBenchNV on GCC with 2(Dynamic) dimensions of doubles: 0.718s 198KB
>>> EigenBenchV on GCC with 2(Dynamic) dimensions of doubles: 0.78s 275KB
>>> EigenBenchNV on GCC with 8(8) dimensions of floats: 1.01s 225KB
>>> EigenBenchV on GCC with 8(8) dimensions of floats: 0.661s 275KB
>>> EigenBenchNV on GCC with 8(Dynamic) dimensions of floats: 1.44s 202KB
>>> EigenBenchV on GCC with 8(Dynamic) dimensions of floats: 1.17s 264KB
>>>
>>> At tip changeset 4321 (47b90dc56ada) Add test for Matrix(x, y) ctor static
>>> assert added in previous changeset:
>>> EigenBenchNV on GCC with 2(2) dimensions of doubles: 0.258s 201KB
>>> EigenBenchV on GCC with 2(2) dimensions of doubles: 0.23s 272KB
>>> EigenBenchNV on GCC with 2(Dynamic) dimensions of doubles: 0.844s 205KB
>>> EigenBenchV on GCC with 2(Dynamic) dimensions of doubles: 0.909s 290KB
>>> EigenBenchNV on GCC with 8(8) dimensions of floats: 1.13s 227KB
>>> EigenBenchV on GCC with 8(8) dimensions of floats: 0.802s 291KB
>>> EigenBenchNV on GCC with 8(Dynamic) dimensions of floats: 1.58s 210KB
>>> EigenBenchV on GCC with 8(Dynamic) dimensions of floats: 1.31s 283KB
>>>
>>>
>>> MSC isn't affected, and performs roughly comparably regardless:
>>> EigenBenchNV on MSC with 2(2) dimensions of doubles: 0.3s 149KB
>>> EigenBenchV on MSC with 2(2) dimensions of doubles: 0.252s 169KB
>>> EigenBenchNV on MSC with 2(Dynamic) dimensions of doubles: 1s 160KB
>>> EigenBenchV on MSC with 2(Dynamic) dimensions of doubles: 0.938s 185KB
>>> EigenBenchNV on MSC with 8(8) dimensions of floats: 1.27s 168KB
>>> EigenBenchV on MSC with 8(8) dimensions of floats: 1.01s 185KB
>>> EigenBenchNV on MSC with 8(Dynamic) dimensions of floats: 1.93s 159KB
>>> EigenBenchV on MSC with 8(Dynamic) dimensions of floats: 1.61s 184KB
>>>
>>>
>>> So for GCC there's a slowdown in all scenarios although it's relatively more
>>> significant in the cheapest (2d) cases.
>>>
>>> --eamon@xxxxxxxxxxxx - Tel#:+31-6-15142163
>>>
>>>
>>> On Sun, Nov 6, 2011 at 05:29, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
>>>>
>>>> 2011/11/5 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
>>>> > So this is really a bug in your code; did this ever work? Meanwhile,
>>>> > we should try to generate an error at compile time in this case. This
>>>> > should be easy since x and y are of templated type so we get to know
>>>> > (in frame 3) that they're floats which doesn't make sense for (rows,
>>>> > cols) dimensions.
>>>>
>>>> Done in changeset c6f51dc87530 , so your code now gives this compile
>>>> error:
>>>>
>>>> In file included from eigen/Eigen/Core:289:0,
>>>>                 from eigen/bench/BenchTimer.h:46,
>>>>                 from Downloads/GgmLvqBench.cpp:25:
>>>> eigen/Eigen/src/Core/PlainObjectBase.h: In member function ‘void
>>>>
>>>> Eigen::PlainObjectBase<Derived>::_init2(Eigen::PlainObjectBase<Derived>::Index,
>>>> Eigen::PlainObjectBase<Derived>::Index, typename
>>>> Eigen::internal::enable_if<(Eigen::PlainObjectBase<Derived>::Base::
>>>> SizeAtCompileTime != 2), T0>::type*) [with T0 = float, T1 = float,
>>>> Derived = Eigen::Matrix<float, 4, 1>,
>>>> Eigen::PlainObjectBase<Derived>::Index = long int, typename
>>>> Eigen::internal::enable_if<(Eigen::PlainObjectBase<Derived>::Base::
>>>> SizeAtCompileTime != 2), T0>::type = float]’:
>>>> eigen/Eigen/src/Core/Matrix.h:252:7:   instantiated from
>>>> ‘Eigen::Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows,
>>>> _MaxCols>::Matrix(const T0&, const T1&) [with T0 = float, T1 = float,
>>>> _Scalar = float, int _Rows = 4, int _Cols = 1, int _Options = 0, int
>>>> _MaxRows = 4, int _MaxCols = 1]’
>>>> Downloads/GgmLvqBench.cpp:386:76:   instantiated from here
>>>> eigen/Eigen/src/Core/PlainObjectBase.h:599:7: error: static assertion
>>>> failed: "FLOATING_POINT_ARGUMENT_PASSED__INTEGER_WAS_EXPECTED"
>>>>
>>>> Benoit
>>>>
>>>>
>>>
>>>
>>
>