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

[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
>>
>>
>
>