[patch, fortran] Some fewer temporaries

[Tobias Burnus]

Hello Thomas,

> OK for trunk?

OK. I like the patch - while it does a more comprehensive analysis the 
patch is not more complicated than before. You add some complexity, but 
you also do some clean up.

Tobias

> 2010-11-29  Thomas Koenig<tkoenig@gcc.gnu.org>
>
> 	PR fortran/45159
> 	* dependency.c (check_section_vs_section):  Pre-calculate
> 	the relationship between the strides and the relationship
> 	between the start values.  Use an integer constant one for
> 	that purpose.
> 	Forward dependencies for positive strides apply for where
> 	the lhs start<= rhs start and lhs stride<= rhs stride
> 	and vice versa for negative stride.  No need to compare
> 	end expressions in either case (assume no bounds violation).
>
> 2010-11-29  Thomas Koenig<tkoenig@gcc.gnu.org>
>
> 	PR fortran/45159
> 	* gfortran.dg/dependency_38.f90:  New test.
>
>