------- Comment #3 from bangerth at dealii dot org 2007-10-01 17:16 -------
For once a real floating point bug. In this code
double p = 0.422244 * f[a.e];
if (f[0] < p)
with a.e=1, f[1]=0.285433, we should calculate p=0.285433. Since
f[0]=0.0461109, we shouldn't enter the if-clause, but we do when
optimization is on. Since the numbers aren't even close, this isn't
due to excess precision or any other floating point instability but
a real bug.
Funny enough, this was already broken in 2.95, 3.2.3 and 3.3.6 but then
worked in 3.4.6 and 4.0.x only to be broken again in 4.1.2.
W.
--
bangerth at dealii dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bangerth at dealii dot org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Keywords| |wrong-code
Known to fail| |2.95 3.2.3 3.3.6 4.1.2
Known to work| |3.4.6 4.0.4
Last reconfirmed|0000-00-00 00:00:00 |2007-10-01 17:16:44
date| |
Summary|Optimizations generate |[4.1/4.2/4.3 regression]
|incorrect code |Optimizations generate
| |incorrect code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33611
