On Mon, 2007-04-09 at 16:26 +0200, Dragan Noveski wrote: > Mike Taht wrote: > > does jack say it's running SSE on startup? > now, since i recompiled with --enable-dynsimd it says: > > ... > JACK tmpdir identified as [/dev/shm/] > SSE2 detected > load = 0.2297 max usecs: 40.000, spare = 10626.000 > ... > > looks like a nice hint?? > > what is about processor type and architecture? > are there more hints about optimizing? Enabling SSE throughout the project via compiler flags makes the resulting code /depend/ on SSE. In other words, running that on a platform with no SSE will result in "Illegal instruction (core dumped)". In projects like jackd and Ardour there are places which can be improved vastly via SSE code. Creating a framework which can enable SSE / etc. per the platform the binary is ran makes it possible for distributions to include optimized versions of the software which will work on any x86 platform. I have heard good things about the current development branch of gcc, but gcc 4.1 still has a _long_ way to go when it comes to vectorizing (=writing code using parallel SIMD instructions, in other words SSE). Hand written assembler is still many orders faster than what gcc is capable of doing. In Ardour peak computation (for both metering and waveform displaying) is written in SSE (the first part in pure assembly, the second in a C-level abstraction which is almost 1:1 assembly). Both functions are more than 20x faster in raw performance than what gcc 4.1 can do. Sampo _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
