http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51535
Tobias Burnus <burnus at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |burnus at gcc dot gnu.org
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-12-14
07:48:27 UTC ---
The issue seems to be related to the excess precision of the x87 math unit. At
least, I do not see the issue with x86-86-linux with -m64. I do see it with
-m32 but only if I do not use -mfpmath=sse.
The reason that it disappears with -O2 is that the NaN assignment is optimized
way.
>From the dump (-fdump-tree-optimized-lineno):
p_h_usstd (real(kind=4) & restrict h)
...
[test.f90 : 7:0] sigma = Nan;
[test.f90 : 7:0] delta = Nan;
The backtrace shows that the exception occurs for line 7.
