[Wien] WIEN2k 12 fft_modules & symmetry
Laurence Marks
L-marks at northwestern.edu
Mon Jul 30 03:05:59 CEST 2012
If the first declaration is lm(2,49) then in later ones it does not
matter (in standard fortran) if it is declared lm(2,1), lm(2,*) or
lm(2,48) -- although lm(2,50) could be problematic. The reason is that
the size of the array is 2*49 and so long as this is not exceeded
everything is fine -- the locations go first over the first index,
then in order (the opposite to C). The "-C" option in fact checks some
this which are allowed in fortran and slightly incorrectly calls it an
error.
I think it should be 48 everywhere -- I will leave this to Peter who
will probably correct it.
On Sun, Jul 29, 2012 at 5:49 PM, Gavin Abo <gsabo at crimson.ua.edu> wrote:
> Thanks, Prof. Marks. Your explanation is better than mine. Yes, almost
> certainly the default -r4 is used for -O2, but by luck it is not truncating
> the variable.
>
> By the way, do you think it is also by luck that the ifort compiler produces
> an "x symmetry" executable that does not crash with a memory access
> violation outside the lm array for certain structures? If you check
> SRC_symmetry/class.f on line 8, the array is allocated as lm(2,49).
> However, the array is only allocated as lm(2,48) in kurki.f on line 3.
> Since class.f and kurki.f in SRC_symmetso both have lm(2,49), it suggests
> lm(2,48) should be replaced by lm(2,49). This would affect at least Wienk2k
> 11 and 12.
>
> How I caught the potential issue on my system:
>
> 1. Add capitalized -C in SRC_symmetry/Makefile
> 2. make
> 3. cp symmetry ..
> 4. Use in2o3.struct in the Wien2k folder example_struct_files
> 5. x symmetry
> 6. The first line in the error message:
>
> forrtl: severe (408): fort: (2): Subscript #2 of the array LM has value 49
> which is greater than the upper bound of 48
>
> When "-C" is not used, the executable runs without error and seems to
> produce the correct output for in2o3. The error cannot be caught with TiC.
>
> On 7/29/2012 2:54 PM, Laurence Marks wrote:
>
> Almost certainly it is trickier than this. I expect that -O1 is
> truncating relevant variables to real*4 which is leading to problems.
> With -O2 the compiler may well be not bothering to truncate and, at
> the end of the space allocated for the variable, by luck the correct
> values are present. This is luck; the same type of bug can in other
> cases lead to segmentation violations when code gets overwritten.
>
> N.B., I think there are only two places where real*4 variables are
> used, in parts of aim and for storage of the Hamiltonian in lapw1.
> Everything else should be real*8.
>
> On Sun, Jul 29, 2012 at 3:05 PM, Gavin Abo <gsabo at crimson.ua.edu> wrote:
>
> I didn't use -r8. However, you are right. The scf cycle works
> correctly if I use "-O1 -r8".
>
> So the higher optimizations -O2 and -O3 must be invoking the use of -r8,
> whereas -O0 and -O1 should be using the default -r4.
>
> On 7/29/2012 1:40 PM, Laurence Marks wrote:
>
> I have not tested, but it looks like you are probably right. There may
> be other cases where variables are not explicitly defined to be 8
> bytes which are normally hidden by the use of "-r8". Did you use -r8?
>
> On Sun, Jul 29, 2012 at 1:57 PM, Gavin Abo <gsabo at crimson.ua.edu> wrote:
>
> Dear Prof. Blaha,
>
> Thanks, the scf cycle runs correctly using -O2 or -O3 with the new
> files for the "fftpack" routines. However, the scf cycle of the TiC
> example does not converge with -O1 (in the lapw0 makefile) with wrong
> values in TiC.output0 such as the plane wave contribution. I don't
> know whether the problem is reproducible on another system.
>
> It seems to be due to "IMPLICIT REAL*8 (A-H,O-Z)" not being in the
> PIMACH function at the end of the fortran file fftpack_helpers.f.
> This line is in the function in the old file zfft3d.F.
>
> Kind Regards,
>
> Gavin
>
> On Thu, Jul 26, 2012 at 1:42 AM, Peter Blaha
> <pblaha at theochem.tuwien.ac.at> wrote:
>
> Thank's for the report.
>
> The problem concerns lapw0, when compiled in sequential mode WITHOUT
> -DFFTW2 or -DFFTW3
> in the Makefile (i.e. using the old "fftpack" routines instead of the new
> and faster fftw library).
>
> The fix suggested in the mail below does not work. Instead, you have to
> replace the 3 attached
> subroutines and recompile. (eramps.f, fft_modules.F fftpack_helpers.f)
>
> A corrected version is on the web.
>
> PB
>
>
> Am 25.07.2012 23:21, schrieb Gavin Abo:
>
> Dear Prof. Blaha,
>
> When I run the TiC example with WIEN2k 12 "without" k-point or mpi
> parallelization, the program stops in lapw2 with the error shown below.
> Here lapw2 cannot read the TiC.energy
> file, because it is missing data in it as lapw0 gives bad output such as a
> Density Integral with the value NaN in TiC.output0.
>
> The problem seems to be related to the new fft module.
>
> If lines 536-538 and 612-614 in SRC_lapw0/fft_modules.F:
>
> N2 = N+N
> DO 117 I=1,N2
> C(I) = CH(I)
>
> are both changed to:
>
> DO 117 I=1,N
> C(I) = CH(I)
>
> Then, the error goes way. On my system, N was the number 64. The array C
> had a size of 64, such that the loop is indexing outside the array (N2 =
> 128).
>
> In Wien2k 11, TiC.output0 had:
>
> PLANE WAVE CONTRIBUTION -0.235589
> :DEN : DENSITY INTEGRAL = -754.35311720 (Ry)
>
> In Wien2k 12 with both changes made in fft_modules.F, TiC.output0 had:
>
> PLANE WAVE CONTRIBUTION -0.049778
> :DEN : DENSITY INTEGRAL = -753.97972930 (Ry)
>
> The density integral value is about the same, but the plane wave
> contribution value may be significantly different. So I'm not completely
> sure if my change is correct.
> Therefore, please let me know if a different change is needed.
>
> Thanks,
>
> Gavin
>
> forrtl: severe (59): list-directed I/O syntax error, unit 30, file
> /home/gavin/wien/wiendata/TiC/TiC.energy
> Image PC Routine Line Source
> lapw2 000000000053676A Unknown Unknown Unknown
> lapw2 0000000000535266 Unknown Unknown Unknown
> lapw2 00000000004DFA30 Unknown Unknown Unknown
> lapw2 000000000049BDEF Unknown Unknown Unknown
> lapw2 000000000049B2F7 Unknown Unknown Unknown
> lapw2 00000000004C10B3 Unknown Unknown Unknown
> lapw2 0000000000437F93 fermi_tetra_ 516 fermi_tmp_.F
> lapw2 0000000000437423 fermi_ 111 fermi_tmp_.F
> lapw2 00000000004721BA MAIN__ 278 lapw2_tmp_.F
> lapw2 0000000000403C9C Unknown Unknown Unknown
> libc.so.6 00002B3BE2AF5C8D Unknown Unknown Unknown
> lapw2 0000000000403B99 Unknown Unknown Unknown
>
> --
>
> P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
> Email: blaha at theochem.tuwien.ac.at WWW:
> http://info.tuwien.ac.at/theochem/
> --------------------------------------------------------------------------
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--
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu 1-847-491-3996
"Research is to see what everybody else has seen, and to think what
nobody else has thought"
Albert Szent-Gyorgi
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