http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50960

--- Comment #13 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-11-03 
14:03:40 UTC ---
Patch for the issue of comment 5: Constants (PARAMETER) which are exists as
global static variables were not marked as TREE_READONLY.

With the patch below (not regtested), the function call is optimized away in:

module m
  integer, parameter :: PARA(*) = [1,2,3,4,5,6,7,8,9,10]
end module m

subroutine test()
use m
integer :: i
i = 1
if (para(i) /= 1) call I_am_optimized_away()
end


--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -517,6 +517,9 @@ gfc_finish_var_decl (tree decl, gfc_symbol * sym)
   /* If it wasn't used we wouldn't be getting it.  */
   TREE_USED (decl) = 1;

+  if (sym->attr.flavor == FL_PARAMETER)
+    TREE_READONLY (decl) = 1;
+
   /* Chain this decl to the pending declarations.  Don't do pushdecl()
      because this would add them to the current scope rather than the
      function scope.  */

Reply via email to