Hello world,

the attached patch is a front-end optimization which replaces multiple 
calls to a function with identical argument lists with an assignment to 
a temporary variable, and then uses that variable in the original 
expression.

AFAIK, this is permitted by the Fortran standard because such functions 
have side effects, the program is illegal.

OK for trunk, now that it has reopened?

	Thomas

2010-03-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/22572
         * frontend_passes (expr_array):  New static variable.
         (expr_size):  Likewise.
         (expr_count):  Likewise.
         (current_code):  Likewise.
         (current_ns):  Likewise.
         (gfc_run_passes):  Allocate and free space for expressions.
         (compare_functions):  New function.
         (cfe_expr):  New function.
         (create_var):  New function.
         (cfc_expr_0):  New function.
         (cfe_code):  New function.
         (optimize_namespace):  Invoke gfc_code_walker with cfe_code
         and cfe_expr_0.

2010-03-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/22572
         * gfortran.dg/function_optimize_1.f90:  New test.