On Sun, Mar 21, 2010 at 04:30:36PM +0100, Vincent Lefevre wrote: > On 2010-03-21 16:14:49 +0100, Aurelien Jarno wrote: > > On Wed, Mar 17, 2010 at 11:29:00AM +0100, Vincent Lefevre wrote: > > > It may be optimized, but completely buggy. For instance, on 1e22, > > > sincos returns 0.46261304076460174617 for the sine instead of > > > -0.85220084976718879499 (correctly rounded value). Even the sign > > > is incorrect! > > > > Where did you get this result? In my tests both the x87 FPU and the > > current glibc code give the following result when using double variables > > and the sincos() function: > > > > sin (1e22) = 0.46261304076460174617 > > cos (1e22) = -0.88656030506363692201 > > Actually the sincos() function uses the x87 FPU (fsincos instruction), > so that's not surprising that you get the same result. >
That just means that the precision is not an argument for switching to the x87 FPU version, contrary to what your first email suggested. Both are wrong. -- 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/20100321195501.gc11...@hall.aurel32.net
