[PATCH] fortran/30207 -- Fix a WHERE and array section problem

[Paul Thomas]

Roger and Steve,
> Ok for mainline?  My apologies for any potential e-mail problems; I'm
> using a new mail client and this is my first attempt posting a patch
> to gcc-patches/fortran with it.  Hopefully, the attachment will be fine,
> but it seems to insist on wrapping my ChangeLog entry :-(
>   
I'm sorry that I took a little bit with this - I was checking out some 
simpler alternatives.... which broke things!

OK for trunk and, I would suggest, 4.2 after a week or so of digestion!

Thanks to you both

Paul
>
>
> 2006-12-14  Roger Sayle  <roger@eyesopen.com>
>
>         PR fortran/30207
>         * dependency.c (gfc_full_array_ref_p): New function to test whether
>         the given array ref specifies the entire array.
>         (gfc_dep_resolver): Use gfc_full_array_ref_p to analyze AR_FULL
>         array refs against AR_SECTION array refs, and vice versa.
>         * dependency.h (gfc_full_array_ref_p): Prototype here.
>         * trans-array.c (gfc_conv_expr_descriptor):Use gfc_full_array_ref_p.
>
> 2006-12-14  Steven G. Kargl  <kargl@gcc.gnu.org>
>
>         PR fortran/30207
>         * gfortran.fortran-torture/execute/where21.f90: New test.
>
>   
> ------------------------------------------------------------------------
>
> Index: dependency.c
> ===================================================================
> *** dependency.c	(revision 119864)
> --- dependency.c	(working copy)
> *************** gfc_check_element_vs_element (gfc_ref * 
> *** 1108,1113 ****
> --- 1108,1153 ----
>   }
>   
>   
> + /* Determine if an array ref, usually an array section specifies the
> +    entire array.  */
> + 
> + bool
> + gfc_full_array_ref_p (gfc_ref *ref)
> + {
> +   int i;
> + 
> +   if (ref->type != REF_ARRAY)
> +     return false;
> +   if (ref->u.ar.type == AR_FULL)
> +     return true;
> +   if (ref->u.ar.type != AR_SECTION)
> +     return false;
> + 
> +   for (i = 0; i < ref->u.ar.dimen; i++)
> +     {
> +       /* Check the lower bound.  */
> +       if (ref->u.ar.start[i]
> + 	  && (!ref->u.ar.as
> + 	      || !ref->u.ar.as->lower[i]
> + 	      || gfc_dep_compare_expr (ref->u.ar.start[i],
> + 				       ref->u.ar.as->lower[i])))
> + 	return false;
> +       /* Check the upper bound.  */
> +       if (ref->u.ar.end[i]
> + 	  && (!ref->u.ar.as
> + 	      || !ref->u.ar.as->upper[i]
> + 	      || gfc_dep_compare_expr (ref->u.ar.end[i],
> + 				       ref->u.ar.as->upper[i])))
> + 	return false;
> +       /* Check the stride.  */
> +       if (ref->u.ar.stride[i]
> + 	  && !gfc_expr_is_one (ref->u.ar.stride[i], 0))
> + 	return false;
> +     }
> +   return true;
> + }
> + 
> + 
>   /* Finds if two array references are overlapping or not.
>      Return value
>      	1 : array references are overlapping.
> *************** gfc_dep_resolver (gfc_ref * lref, gfc_re
> *** 1145,1150 ****
> --- 1185,1203 ----
>   	  return 0;
>   	
>   	case REF_ARRAY:
> +           if (lref->u.ar.dimen != rref->u.ar.dimen)
> + 	    {
> + 	      if (lref->u.ar.type == AR_FULL)
> + 		fin_dep = gfc_full_array_ref_p (rref) ? GFC_DEP_EQUAL
> + 						      : GFC_DEP_OVERLAP;
> + 	      else if (rref->u.ar.type == AR_FULL)
> + 		fin_dep = gfc_full_array_ref_p (lref) ? GFC_DEP_EQUAL
> + 						      : GFC_DEP_OVERLAP;
> + 	      else
> +                 return 1;
> + 	      break;
> + 	    }
> + 
>   	  for (n=0; n < lref->u.ar.dimen; n++)
>   	    {
>   	      /* Assume dependency when either of array reference is vector
> Index: dependency.h
> ===================================================================
> *** dependency.h	(revision 119864)
> --- dependency.h	(working copy)
> *************** Software Foundation, 51 Franklin Street,
> *** 22,27 ****
> --- 22,28 ----
>   
>   
>   bool gfc_ref_needs_temporary_p (gfc_ref *);
> + bool gfc_full_array_ref_p (gfc_ref *);
>   gfc_expr *gfc_get_noncopying_intrinsic_argument (gfc_expr *);
>   int gfc_check_fncall_dependency (gfc_expr *, sym_intent, gfc_symbol *,
>   				 gfc_actual_arglist *);
> Index: trans-array.c
> ===================================================================
> *** trans-array.c	(revision 119864)
> --- trans-array.c	(working copy)
> *************** gfc_conv_expr_descriptor (gfc_se * se, g
> *** 4147,4153 ****
>     tree start;
>     tree offset;
>     int full;
> -   gfc_ref *ref;
>   
>     gcc_assert (ss != gfc_ss_terminator);
>   
> --- 4147,4152 ----
> *************** gfc_conv_expr_descriptor (gfc_se * se, g
> *** 4184,4208 ****
>         else if (se->direct_byref)
>   	full = 0;
>         else
> ! 	{
> ! 	  ref = info->ref;
> ! 	  gcc_assert (ref->u.ar.type == AR_SECTION);
> ! 
> ! 	  full = 1;
> ! 	  for (n = 0; n < ref->u.ar.dimen; n++)
> ! 	    {
> ! 	      /* Detect passing the full array as a section.  This could do
> ! 	         even more checking, but it doesn't seem worth it.  */
> ! 	      if (ref->u.ar.start[n]
> ! 		  || ref->u.ar.end[n]
> ! 		  || (ref->u.ar.stride[n]
> ! 		      && !gfc_expr_is_one (ref->u.ar.stride[n], 0)))
> ! 		{
> ! 		  full = 0;
> ! 		  break;
> ! 		}
> ! 	    }
> ! 	}
>   
>         if (full)
>   	{
> --- 4183,4189 ----
>         else if (se->direct_byref)
>   	full = 0;
>         else
> ! 	full = gfc_full_array_ref_p (info->ref);
>   
>         if (full)
>   	{