On Wed, Apr 10, 2013 at 6:36 AM, Carlos E. R.
Now, not sure what did libm does, but the "fast and wrong" version didn't even call fprem, so I guess the slowdown could come from it (since it has to be invoked in a loop). If not, using fprem may be much faster than invoking libm.
I guess this could be testing by calling sincos(fmod(x, M_PI)) on the old, inaccurate gcc version, and checking the result.
In the forum thread I mentioned at the start there are some posts listing other math libraries, some commercial, that give better results. But it needs rebuild of the affected applications, of course.
Besides the horrible typos in my post, I did try, on 12.2 and 11.4, and couldn't find evidence of fmod helping in any way (though it did change results, not sure it was for the better or worse), nor of sin and sincos disagreeing at any point, as per the OP bug report. In essence, I could not reproduce the bug. sin and sincos always agreed. If the results were right or not, I could not tell. I'll have to carefully implement power series expansion to test that, and though I might do it just for the lulz, it might be over my enthusiasm level ;) -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org