[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From tobi at gcc dot gnu dot org 2004-12-20 22:40 --- The problem is an out-of-bounds array access to sa, note its dimensions and the values the loop index takes on. -- What|Removed |Added CC||tobi at gcc dot gnu dot org Status|NEW |RESOLVED Resolution||INVALID http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From tobi at gcc dot gnu dot org 2004-12-20 22:40 --- Forgot to say: this bug is caught by -fbounds-check. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From Tobias dot Schlueter at physik dot uni-muenchen dot de 2004-12-21 00:04 --- Subject: Re: Gfortran produces wrong output (c/f to g77) Deji Akingunola wrote: --- Additional Comments From tobi at gcc dot gnu dot org 2004-12-20 22:40 --- The problem is an out-of-bounds array access to sa, note its dimensions and the values the loop index takes on. I'm sorry I don't get the above, what do you mean by 'out-of-bound array access to sa' (what's sa). I wonder why it's tagged invalid while other compilers does successfully execute the same code. Does it mean one has to pass some special options to gfortran to produce the right result. Thanks. The code has a bug. It's not gfortran's fault that it doesn't work with gfortran. 'sa' is an array in that code. It is accessed out of bounds in the loop of the main program. This is caught at runtime, if the code is compiled with '-fbounds-check'. The problem only appears on i686 by hazard. 'The code works if compiled with other compilers' doesn't mean 'the code is correct and bug-free', unfortunately. If you're still not convinced, lean back, look at the following five lines of code (which are extracted from your testcase), and try to figure out what the code means for all possible values of 'i'. parameter(n=8) real sa(n) do 20,i=1,2*n-1,2 sa(i)=a(i)**2+a(i+1)**2 20 continue Regards, - Tobi ps I think you really want that loop to look like do i=2, 2*n, 2 sa(i/2) = a(i-1)**2 + a(i)**2 end do or something similar. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From Thomas dot Koenig at online dot de 2004-12-16 11:47 --- The code runs correctly on IA-64. $ gfortran fft2.for $ ./a.out 0.00 0.00 0.00 0.00 4.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.00 0.00 0.00 0.00 STOP 0 $ gfortran -O3 fft2.for $ ./a.out 0.00 0.00 0.00 0.00 4.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.00 0.00 0.00 0.00 STOP 0 For comparison: $ ifort fft2.for $ ./a.out 0.000E+00 0.000E+00 0.000E+00 0.000E+00 4.00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 4.00 0.000E+00 0.000E+00 0.000E+00 $ gfortran -v Reading specs from /home/zfkts/lib/gcc/ia64-unknown-linux-gnu/4.0.0/specs Configured with: ../gcc-4.0-20041212/configure --prefix=/home/zfkts --enable-languages=c,c++,f95 : (reconfigured) ../gcc-4.0-20041212/configure --prefix=/home/zfkts --enable-languages=c,c++,f95 --disable-shared Thread model: posix gcc version 4.0.0 20041212 (experimental) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-12-14 19:40 --- This works for me on ppc-darwin with gcc 4.0.0 (20041214). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From tobi at gcc dot gnu dot org 2004-12-14 22:29 --- I'm seeing the same result as Deji on i686-pc-linux. [EMAIL PROTECTED] tests]$ gfortran --version GNU Fortran 95 (GCC 4.0.0 20041210 (experimental)) Copyright (C) 2004 Free Software Foundation, Inc. GNU Fortran comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of GNU Fortran under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING -- What|Removed |Added Status|UNCONFIRMED |NEW Ever Confirmed||1 Last reconfirmed|-00-00 00:00:00 |2004-12-14 22:29:23 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From deji_aking at yahoo dot ca 2004-12-14 19:30 --- Created an attachment (id=7744) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7744action=view) FFT code -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From deji_aking at yahoo dot ca 2004-12-14 20:06 --- (In reply to comment #2) This works for me on ppc-darwin with gcc 4.0.0 (20041214). I should add that I noticed the problem with gcc 4.0.0 (20041211) on FC3 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From deji_aking at yahoo dot ca 2004-12-14 20:55 --- (In reply to comment #4) I should add that I noticed the problem with gcc 4.0.0 (20041211) on FC3 That still does not give enough information. What target is this, x86? Yes. I thought I put that in the original bug report. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
[Bug fortran/18998] Gfortran produces wrong output (c/f to g77)
--- Additional Comments From sgk at troutmask dot apl dot washington dot edu 2004-12-14 20:35 --- The compiles and runs correctly on amd64-*-FreeBSD. -- steve -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18998
