On Sun, Mar 07, 2010 at 07:43:46PM +0100, Jerome Vizcaino wrote: > Hi, > > I could not say for sure the difference between sin and sinf (for example) on > Suse but the performance ratio I had on 32 bits, stayed the same on 64 bits. > This is why I was surprised to get impressive slowness when moving to debian > :( > Thanks for pointing out the Suse patch : as we only have Suse or Debian at > work > I could not do more comparisons. > > How about including patches from OpenSuse ? Is it possible as a quick > workaround? >
The patches from OpenSuse are ugly and very invasive, and they do not seem to include the recent errno changes for C99 compliance (though I haven't tested them). I am not really sure we want that. I have started to rewrite part of the functions in assembly. While this new assembly code behaves correctly with your testcase, it is twice slower than the current version when using normal arguments. I have modified a bit your code to stay within a reasonable range of arguments, and also test the l version of the functions. Here is the result with the original code (using C code for the f version): | Testing 10000000 sinf, cosf and tanf... Result: 19764686.000000, Duration: 0.516700 sec | Testing 10000000 sin, cos and tan (with float args)... Result: 19764686.000000, Duration: 1.056214 sec | Testing 10000000 sinl, cosl and tanl (with float args)... Result: 19764686.000000, Duration: 1.089871 sec Here is the result with assembly code instead (using the FPU instructions), I get instead: | Testing 10000000 sinf, cosf and tanf... Result: 19764686.000000, Duration: 1.010248 sec | Testing 10000000 sin, cos and tan (with float args)... Result: 19764686.000000, Duration: 1.055434 sec | Testing 10000000 sinl, cosl and tanl (with float args)... Result: 19764686.000000, Duration: 1.095374 sec As I expect most codes to use values between -2pi and 2pi, I am not really sure we should change the current code. -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurel...@aurel32.net http://www.aurel32.net -- To UNSUBSCRIBE, email to debian-glibc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100307210105.ge...@hall.aurel32.net
