The quest for auto-vectorization continues. Introducing the Intel icc/icpc combo (scroll down ...)
On Wed, 2008-04-16 at 17:37 +0200, [EMAIL PROTECTED] wrote: > On Wed, Apr 16, 2008 at 04:46:10PM +0200, Jens M Andreasen wrote: > > Benchmarking mixdown (no coeff): > > pure C++ : 100 ms > > ASM SSE : 140 ms > > GCC vector extensions : 120 ms > > > > Benchmarking mixdown (WITH coeff): > > pure C++ : 120 ms > > ASM SSE : 150 ms > > GCC vector extensions : 170 ms > > > > One more time for those who missed it the first time, this time > > commenting out everything but 'pure cpp w coff': > > > > Benchmarking mixdown (WITH coeff): > > pure C++ : 120 ms <-- bloody murder! > > hmm.. perhaps i should upgrade my gcc... > If you want to upgrade for speed, consider icc as well. This test is again the "pure CPP" loop only as per above: [EMAIL PROTECTED] mixdown]# make icpc -O3 -msse -c mixdown.cpp mixdown.cpp(159): (col. 9) remark: PERMUTED LOOP WAS VECTORIZED. mixdown.cpp(58): (col. 5) remark: LOOP WAS VECTORIZED. mixdown.cpp(54): (col. 5) remark: LOOP WAS VECTORIZED. icpc -O3 -msse -o mixdown *.o [EMAIL PROTECTED] mixdown]# ./mixdown Benchmarking mixdown (WITH coeff): : 80 ms <-- shaved off yet another 30% > on the vector extension: > > you should not use it. use xmmintrin.h which even exists on MSVC to > make code compatible... however altivec is not supported then. > I spend about 20 - 30 minutes on checking pre-conditions, post-conditions and reordering/doubling the ASM in the loop for these two lines of C code, to match the results from g++. I dunno how long time it would (hypothetically) take to match the output from icpc? More interresting would be some "real" code. I just did a preliminary test on a 4-pole filter written in C that I have here. It compiles and something appeared to happen in the vector department, but I am not sure how much or what, yet .. For Altivec: Isn't it so that IBM has some nifty auto-vectorizing compilers as well? > > > > > > > > > _______________________________________________ > > Linux-audio-dev mailing list > > Linux-audio-dev@lists.linuxaudio.org > > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev > -- _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev