[Bug fortran/53086] [4.8 Regression] 416.gamess in SPEC CPU 2006 miscompiled

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53086

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |kargl at gcc dot gnu.org

--- Comment #4 from kargl at gcc dot gnu.org 2012-04-23 16:09:46 UTC ---
(In reply to comment #3)
> If it is valid to have such "trailing array" in a COMMON then we need to fix
> array sizes for them (that's possible).
> 
> Is this valid fortran?  If so this is a Frontend bug as well - -fbounds-check
> triggers after all.

>From F2003 standard one finds on page 99:

   The form variable-name (explicit-shape-spec-list) declares variable-name
   to have the DIMENSION attribute and specifies the array properties that
   apply.

My interpretation is that

      COMMON /FMCOM / X(1)

declares X to have 1 element while

      PARAMETER (MEMSIZ=   80 000 000)
      COMMON /FMCOM / X(MEMSIZ)

has 80000000 elements.  The above appears to be a common
F77 idiom for "dynamic" memory management where the 
programmer is abusing the storage association of element
x(1).