2015-03-23 Paul Thomas <pault@gcc.gnu.org>

	    Mikael Morin  <mikael@gcc.gnu.org>

	PR fortran/64952
fortran/
	* gfortran.h (struct symbol_attribute) : New field
	'array_outer_dependency'.
	* trans.h (struct gfc_ss_info): New field 'array_outer_dependency'.
	* module.c (enum ab_attribute): New value AB_ARRAY_OUTER_DEPENDENCY.
	(attr_bits): Append same value to initializer.
	(mio_symbol_attribute): Handle 'array_outer_dependency' attr
	in module read and write.
	* resolve.c (update_current_proc_outer_array_dependency): New function.
	(resolve_function, resolve_call): Add code to update current procedure's
	'array_outer_dependency' attribute.
	(resolve_variable): Mark current procedure with attribute
	array_outer_dependency if the variable is an array coming from outside
	the current namespace.
	(resolve_fl_procedure): Mark a procedure without body with attribute
	'array_outer_dependency'.
	* trans-array.c (gfc_conv_resolve_dependencies): If any ss is
	marked as 'array_outer_dependency' generate a temporary.
	(gfc_walk_function_expr): If the function may reference external arrays,
	mark the head gfc_ss with flag 'array_outer_dependency'.
testsuite/
	* gfortran.dg/elemental_dependency_4.f90: New.
	* gfortran.dg/elemental_dependency_5.f90: New.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@221586 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 116 insertions, 2 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index c8c030844fd..473d3192a92 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,27 @@
+2015-03-23  Paul Thomas  <pault@gcc.gnu.org>
+	    Mikael Morin  <mikael@gcc.gnu.org>
+
+	PR fortran/64952
+	* gfortran.h (struct symbol_attribute) : New field
+	'array_outer_dependency'.
+	* trans.h (struct gfc_ss_info): New field 'array_outer_dependency'.
+	* module.c (enum ab_attribute): New value AB_ARRAY_OUTER_DEPENDENCY.
+	(attr_bits): Append same value to initializer.
+	(mio_symbol_attribute): Handle 'array_outer_dependency' attr
+	in module read and write.
+	* resolve.c (update_current_proc_outer_array_dependency): New function.
+	(resolve_function, resolve_call): Add code to update current procedure's
+	'array_outer_dependency' attribute.
+	(resolve_variable): Mark current procedure with attribute
+	array_outer_dependency if the variable is an array coming from outside
+	the current namespace.
+	(resolve_fl_procedure): Mark a procedure without body with attribute
+	'array_outer_dependency'.
+	* trans-array.c (gfc_conv_resolve_dependencies): If any ss is
+	marked as 'array_outer_dependency' generate a temporary.
+	(gfc_walk_function_expr): If the function may reference external arrays,
+	mark the head gfc_ss with flag 'array_outer_dependency'.
+
 2015-03-22 Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libgfortran/59513
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index ff0054e7029..9be20109bf6 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -789,6 +789,13 @@ typedef struct
      cannot alias.  Note that this is zero for PURE procedures.  */
   unsigned implicit_pure:1;
 
+  /* This is set for a procedure that contains expressions referencing
+     arrays coming from outside its namespace.  
+     This is used to force the creation of a temporary when the LHS of
+     an array assignment may be used by an elemental procedure appearing
+     on the RHS.  */
+  unsigned array_outer_dependency:1;
+
   /* This is set if the subroutine doesn't return.  Currently, this
      is only possible for intrinsic subroutines.  */
   unsigned noreturn:1;
diff --git a/gcc/fortran/module.c b/gcc/fortran/module.c
index b12f8247a91..1abfc46d7a5 100644
--- a/gcc/fortran/module.c
+++ b/gcc/fortran/module.c
@@ -1893,7 +1893,8 @@ typedef enum
   AB_IS_BIND_C, AB_IS_C_INTEROP, AB_IS_ISO_C, AB_ABSTRACT, AB_ZERO_COMP,
   AB_IS_CLASS, AB_PROCEDURE, AB_PROC_POINTER, AB_ASYNCHRONOUS, AB_CODIMENSION,
   AB_COARRAY_COMP, AB_VTYPE, AB_VTAB, AB_CONTIGUOUS, AB_CLASS_POINTER,
-  AB_IMPLICIT_PURE, AB_ARTIFICIAL, AB_UNLIMITED_POLY, AB_OMP_DECLARE_TARGET
+  AB_IMPLICIT_PURE, AB_ARTIFICIAL, AB_UNLIMITED_POLY, AB_OMP_DECLARE_TARGET,
+  AB_ARRAY_OUTER_DEPENDENCY
 }
 ab_attribute;
 
@@ -1949,6 +1950,7 @@ static const mstring attr_bits[] =
     minit ("IMPLICIT_PURE", AB_IMPLICIT_PURE),
     minit ("UNLIMITED_POLY", AB_UNLIMITED_POLY),
     minit ("OMP_DECLARE_TARGET", AB_OMP_DECLARE_TARGET),
+    minit ("ARRAY_OUTER_DEPENDENCY", AB_ARRAY_OUTER_DEPENDENCY),
     minit (NULL, -1)
 };
 
@@ -2129,6 +2131,8 @@ mio_symbol_attribute (symbol_attribute *attr)
 	MIO_NAME (ab_attribute) (AB_VTAB, attr_bits);
       if (attr->omp_declare_target)
 	MIO_NAME (ab_attribute) (AB_OMP_DECLARE_TARGET, attr_bits);
+      if (attr->array_outer_dependency)
+	MIO_NAME (ab_attribute) (AB_ARRAY_OUTER_DEPENDENCY, attr_bits);
 
       mio_rparen ();
 
@@ -2295,6 +2299,9 @@ mio_symbol_attribute (symbol_attribute *attr)
 	    case AB_OMP_DECLARE_TARGET:
 	      attr->omp_declare_target = 1;
 	      break;
+	    case AB_ARRAY_OUTER_DEPENDENCY:
+	      attr->array_outer_dependency =1;
+	      break;
 	    }
 	}
     }
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 465cf2ba8cf..2a24dfd8eda 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -2866,6 +2866,32 @@ static bool check_pure_function (gfc_expr *e)
 }
 
 
+/* Update current procedure's array_outer_dependency flag, considering
+   a call to procedure SYM.  */
+
+static void
+update_current_proc_array_outer_dependency (gfc_symbol *sym)
+{
+  /* Check to see if this is a sibling function that has not yet
+     been resolved.  */
+  gfc_namespace *sibling = gfc_current_ns->sibling;
+  for (; sibling; sibling = sibling->sibling)
+    {
+      if (sibling->proc_name == sym)
+	{
+	  gfc_resolve (sibling);
+	  break;
+	}
+    }
+
+  /* If SYM has references to outer arrays, so has the procedure calling
+     SYM.  If SYM is a procedure pointer, we can assume the worst.  */
+  if (sym->attr.array_outer_dependency
+      || sym->attr.proc_pointer)
+    gfc_current_ns->proc_name->attr.array_outer_dependency = 1;
+}
+
+
 /* Resolve a function call, which means resolving the arguments, then figuring
    out which entity the name refers to.  */
 
@@ -3090,6 +3116,17 @@ resolve_function (gfc_expr *expr)
 	expr->ts = expr->symtree->n.sym->result->ts;
     }
 
+  if (!expr->ref && !expr->value.function.isym)
+    {
+      if (expr->value.function.esym)
+	update_current_proc_array_outer_dependency (expr->value.function.esym);
+      else
+	update_current_proc_array_outer_dependency (sym);
+    }
+  else if (expr->ref)
+    /* typebound procedure: Assume the worst.  */
+    gfc_current_ns->proc_name->attr.array_outer_dependency = 1;
+
   return t;
 }
 
@@ -3427,6 +3464,12 @@ resolve_call (gfc_code *c)
   if (!resolve_elemental_actual (NULL, c))
     return false;
 
+  if (!c->expr1)
+    update_current_proc_array_outer_dependency (csym);
+  else
+    /* Typebound procedure: Assume the worst.  */
+    gfc_current_ns->proc_name->attr.array_outer_dependency = 1;
+
   return t;
 }
 
@@ -5058,6 +5101,13 @@ resolve_variable (gfc_expr *e)
 		    && gfc_current_ns->parent->parent == sym->ns)))
     sym->attr.host_assoc = 1;
 
+  if (gfc_current_ns->proc_name
+      && sym->attr.dimension
+      && (sym->ns != gfc_current_ns
+	  || sym->attr.use_assoc
+	  || sym->attr.in_common))
+    gfc_current_ns->proc_name->attr.array_outer_dependency = 1;
+
 resolve_procedure:
   if (t && !resolve_procedure_expression (e))
     t = false;
@@ -11494,6 +11544,11 @@ resolve_fl_procedure (gfc_symbol *sym, int mp_flag)
 	}
     }
 
+  /* Assume that a procedure whose body is not known has references
+     to external arrays.  */
+  if (sym->attr.if_source != IFSRC_DECL)
+    sym->attr.array_outer_dependency = 1;
+
   return true;
 }
 
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index 642110dc41f..0dbfdaab1b2 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -4391,6 +4391,12 @@ gfc_conv_resolve_dependencies (gfc_loopinfo * loop, gfc_ss * dest,
     {
       ss_expr = ss->info->expr;
 
+      if (ss->info->array_outer_dependency)
+	{
+	  nDepend = 1;
+	  break;
+	}
+
       if (ss->info->type != GFC_SS_SECTION)
 	{
 	  if (flag_realloc_lhs
@@ -9096,9 +9102,20 @@ gfc_walk_function_expr (gfc_ss * ss, gfc_expr * expr)
   /* Walk the parameters of an elemental function.  For now we always pass
      by reference.  */
   if (sym->attr.elemental || (comp && comp->attr.elemental))
-    return gfc_walk_elemental_function_args (ss, expr->value.function.actual,
+    {
+      gfc_ss *old_ss = ss;
+
+      ss = gfc_walk_elemental_function_args (old_ss,
+					     expr->value.function.actual,
 					     gfc_get_proc_ifc_for_expr (expr),
 					     GFC_SS_REFERENCE);
+      if (ss != old_ss
+	  && (comp
+	      || sym->attr.proc_pointer
+	      || sym->attr.if_source != IFSRC_DECL
+	      || sym->attr.array_outer_dependency))
+	ss->info->array_outer_dependency = 1;
+    }
 
   /* Scalar functions are OK as these are evaluated outside the scalarization
      loop.  Pass back and let the caller deal with it.  */
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 3ba2f88f0fd..be1136382ae 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -226,6 +226,10 @@ typedef struct gfc_ss_info
   /* Suppresses precalculation of scalars in WHERE assignments.  */
   unsigned where:1;
 
+  /* This set for an elemental function that contains expressions for
+     external arrays, thereby triggering creation of a temporary.  */
+  unsigned array_outer_dependency:1;
+
   /* Tells whether the SS is for an actual argument which can be a NULL
      reference.  In other words, the associated dummy argument is OPTIONAL.
      Used to handle elemental procedures.  */