[Bug fortran/22519] New: Memory and binary disk layout disagree for real*10

[schnetter at aei dot mpg dot de]

The memory layout of a real*10 variable on an i386 processor requires 12 or 16 
bytes per variable, depending on the flag -m128bit-long-double.  The disk 
layout for unformatted (binary) writing occupies 10 bytes per variable. 
 
This has several disadvantages.  It is different from I would naively expect 
(which does not mean much), and it is different from binary C I/O (which could 
also be ignored).  However, it is likely also rather inefficient if large 
arrays are written to disk, because a single call to write() or fwrite() now 
has to be split up into one call per array element, so that the padding is 
removed. 
 
It is also questionable whether having a real*10 variable occupy 12 or 16 
bytes in memory is what people expect; again, this could be ignored since the 
standard permits this.  However, this is also very different from what other 
compilers do.

-- 
           Summary: Memory and binary disk layout disagree for real*10
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: schnetter at aei dot mpg dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22519