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Re: [patch, fortran] Unformatted array IO performance improvement
With your patch, the following program causes a segfault on
i686-pc-linux-gnu:
$ cat arrayio_7.f90
program main
character(len=2**25) :: a(2)
a = 'x'
open(10, form="unformatted", access="sequential")
write (10) a
end
$ gfortran -g arrayio_7.f90
$ gdb ./a.out
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This GDB was configured as "i386-linux"...Using host libthread_db library "/lib/tls/libthread_db.so.1".
(gdb) r
Starting program: /home/ig25/Krempel/Array/a.out
Program received signal SIGSEGV, Segmentation fault.
0xb7dbd5ef in memcpy () from /lib/tls/libc.so.6
(gdb) bt
#0 0xb7dbd5ef in memcpy () from /lib/tls/libc.so.6
#1 0xb7f0f3d9 in unformatted_write (type=BT_CHARACTER, source=0x8049b60,
length=-33554432, nelems=2)
at ../../../gcc-4.1/libgfortran/io/transfer.c:356
#2 0xb7f0f623 in *_gfortran_transfer_array (desc=0xbfb40810)
at ../../../gcc-4.1/libgfortran/io/transfer.c:996
#3 0x0804876c in MAIN__ () at arrayio_7.f90:5
#4 0x080487a3 in main (argc=1, argv=0xbfb408c4)
at ../../../gcc-4.1/libgfortran/fmain.c:18
(gdb)
This is probably a signed issue, as the .t02.original file shows
parm.1.dtype = -2147483599;
Can you pass the length of a character array the same way that
the recent patches to the reshape arrays introduced? I think this
would also be more consistent with the size of an array not being
consistent with its string length.
Thomas