+2006-03-25 Roger Sayle <roger@eyesopen.com>
+
+ * dependency.c (gfc_check_dependency): Improve handling of pointers;
+ Two variables of different types can't have a dependency, and two
+ variables with the same symbol are equal, even if pointers.
+
2006-03-24 Roger Sayle <roger@eyesopen.com>
* gfortran.h (gfc_symbol): Add a new "forall_index" bit field.
gcc_assert (expr1->expr_type == EXPR_VARIABLE);
- /* TODO: -fassume-no-pointer-aliasing */
- if (expr1->symtree->n.sym->attr.pointer)
- return 1;
- for (ref = expr1->ref; ref; ref = ref->next)
- {
- if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
- return 1;
- }
-
switch (expr2->expr_type)
{
case EXPR_OP:
return 0;
case EXPR_VARIABLE:
- if (expr2->symtree->n.sym->attr.pointer)
- return 1;
-
- for (ref = expr2->ref; ref; ref = ref->next)
+ /* The interesting cases are when the symbols don't match. */
+ if (expr1->symtree->n.sym != expr2->symtree->n.sym)
{
- if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
+ gfc_typespec *ts1 = &expr1->symtree->n.sym->ts;
+ gfc_typespec *ts2 = &expr2->symtree->n.sym->ts;
+
+ /* Return 1 if expr1 and expr2 are equivalenced arrays. */
+ if (gfc_are_equivalenced_arrays (expr1, expr2))
return 1;
- }
- /* Return 1 if expr1 and expr2 are equivalenced arrays. */
- if (gfc_are_equivalenced_arrays (expr1, expr2))
- return 1;
+ /* Symbols can only alias if they have the same type. */
+ if (ts1->type != BT_UNKNOWN
+ && ts2->type != BT_UNKNOWN
+ && ts1->type != BT_DERIVED
+ && ts2->type != BT_DERIVED)
+ {
+ if (ts1->type != ts2->type
+ || ts1->kind != ts2->kind)
+ return 0;
+ }
- if (expr1->symtree->n.sym != expr2->symtree->n.sym)
- return 0;
+ /* If either variable is a pointer, assume the worst. */
+ /* TODO: -fassume-no-pointer-aliasing */
+ if (expr1->symtree->n.sym->attr.pointer)
+ return 1;
+ for (ref = expr1->ref; ref; ref = ref->next)
+ if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
+ return 1;
+
+ if (expr2->symtree->n.sym->attr.pointer)
+ return 1;
+ for (ref = expr2->ref; ref; ref = ref->next)
+ if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
+ return 1;
+
+ /* Otherwise distinct symbols have no dependencies. */
+ return 0;
+ }
if (identical)
return 1;
--- /dev/null
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a,b)
+ integer, pointer, dimension (:,:) :: a
+ real, dimension(:,:) :: b
+
+ where (a == 0)
+ b = 0.0
+ endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }