On Feb 13, 2008 12:37 PM, Francesc Altet <[EMAIL PROTECTED]> wrote: > A Wednesday 13 February 2008, Francesc Altet escrigué: > > A Wednesday 13 February 2008, Bruce Southey escrigué: > > > Hi, > > > I added gcc 4.2 from the openSUSE 10.1 repository so I now have > > > both the 4.1.2 and 4.2.1 compilers installed. But still have > > > glibc-2.4-31.1 installed. I see your result with 4.2.1 but not with > > > 4.1.2 so I think that there could be a difference in the compiler > > > flags. I don't know enough about those to help but I can test any > > > suggestions. > > > > > > $ gcc --version > > > gcc (GCC) 4.1.2 20070115 (prerelease) (SUSE Linux) > > > $ gcc -O3 sort-string-bench.c -o sort412 > > > $ ./sort412 > > > Benchmark with 1000000 strings of size 15 > > > C qsort with C style compare: 0.630000 > > > C qsort with Python style compare: 0.640000 > > > NumPy newqsort: 0.360000 > > > > > > $ gcc-4.2 --version > > > gcc-4.2 (GCC) 4.2.1 (SUSE Linux) > > > $ gcc-4.2 -O3 sort-string-bench.c -o sort421 > > > $ ./sort421 > > > Benchmark with 1000000 strings of size 15 > > > C qsort with C style compare: 0.620000 > > > C qsort with Python style compare: 0.610000 > > > NumPy newqsort: 0.550000 > > > > > > This is the same as: > > > $ gcc-4.2 -O2 -finline-functions sort-string-bench.c -o sort421 > > > $ ./sort421 > > > Benchmark with 1000000 strings of size 15 > > > C qsort with C style compare: 0.710000 > > > C qsort with Python style compare: 0.700000 > > > NumPy newqsort: 0.550000 > > > > > > (NumPy newqsort with -O2 alone is 0.60000) > > > > > > For completeness, 4.1.2 using '-O2' versus '-O2 -finline-functions' > > > is NumPy newqsort: 0.620000 vs NumPy newqsort: 0.500000 > > > > That's really interesting. Let me remember my figures for our > > Opteron: > > > > 3) SuSe LE 10.3 (gcc 4.2.1, -O3, AMD Opteron @ 2 GHz) > > C qsort with C style compare: 0.640000 > > C qsort with Python style compare: 0.600000 > > NumPy newqsort: 0.590000 > > > > Just an addedum. I've compiled the benchmark using gcc 4.1.2 using our > Opteron machine. Here are the results: > > SuSe LE 10.3 (gcc 4.1.2, -O3, AMD Opteron @ 2 GHz) > Benchmark with 1000000 strings of size 15 > C qsort with C style compare: 0.620000 > C qsort with Python style compare: 0.610000 > NumPy newqsort: 0.380000 > > So, I'm getting a 55% more of performance than by using gcc 4.2.1 (!). > Also, I've installed gcc 4.2.1 on my laptop and here are the results: > > Ubuntu 7.10 (gcc 4.2.1, -O3, Intel Pentium 4 @ 2 GHz) > Benchmark with 1000000 strings of size 15 > C qsort with C style compare: 2.450000 > C qsort with Python style compare: 2.420000 > NumPy newqsort: 0.630000 > > While using gcc 4.1.2, I get: > > Ubuntu 7.10 (gcc 4.1.3, -O3, Intel Pentium 4 @ 2 GHz) > Benchmark with 1000000 strings of size 15 > C qsort with C style compare: 2.450000 > C qsort with Python style compare: 2.440000 > NumPy newqsort: 0.650000 > > So, in this case (32-bit platform) gcc 4.2.1 seems to perform similarly > to 4.1.2. > > So, I'd say that the guilty is the gcc 4.2.1, 64-bit (or at very least, > AMD Opteron architecture) and that newqsort performs really well in > general (provided that the compiler can find the best path for > optimizing its code). Anyone using a 64-bit platform and having both > gcc 4.1.2 and 4.2.1 installed can confirm this? > > Also, MSVC 7.1 32-bit (with opt level /Ox) doesn't seem to find such a > best path (the benchmark for newqsort takes 0.92s using MSVC 7.1, while > gcc 4.1.2 takes 0.65s using the same machine, a 40% faster). I don't > know whether newer versions of MSVC will do better or not, though. >
Now we need someone to try ICC ;) Chuck
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