trans-common.c (create_common): Build RECORD_NODE for common blocks contain no equiva...

	* trans-common.c (create_common): Build RECORD_NODE for common blocks
	contain no equivalence objects.
	(add_equivalences): New argument saw_equiv.
	(trans_common): New local variable saw_equiv.
	(finish_equivalences): Add a local variable dummy, Always pass true
	for the 3rd parameter to create_common.

From-SVN: r97079

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 5999fb6b951005ef602fb98bddd3e8e4bed7bf99..5e93f5f98cfbc9009ce7298cf4481498eeb5b368 100644 (file)
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2005-03-26  Canqun Yang  <canqun@nudt.edu.cn>
+
+       * trans-common.c (create_common): Build RECORD_NODE for common blocks
+       contain no equivalence objects.
+       (add_equivalences): New argument saw_equiv.
+       (trans_common): New local variable saw_equiv.
+       (finish_equivalences): Add a local variable dummy, Always pass true
+       for the 3rd parameter to create_common.
+
 2005-03-25  Steven G. Kargl  <kargls@comcast.net>
 
        * intrinsic.texi: Fix "make dvi"

diff --git a/gcc/fortran/trans-common.c b/gcc/fortran/trans-common.c
index c8db6e745e226e4feb29d15f73d2366be31d9472..42e6712332807814dfe9304f5049c538dbddaaac 100644 (file)
--- a/gcc/fortran/trans-common.c
+++ b/gcc/fortran/trans-common.c
@@ -379,7 +379,7 @@ build_common_decl (gfc_common_head *com, tree union_type, bool is_init)
    backend declarations for all of the elements.  */
 
 static void
-create_common (gfc_common_head *com, segment_info * head)
+create_common (gfc_common_head *com, segment_info * head, bool saw_equiv)
 {
   segment_info *s, *next_s;
   tree union_type;
@@ -388,8 +388,16 @@ create_common (gfc_common_head *com, segment_info * head)
   tree decl;
   bool is_init = false;
 
-  /* Declare the variables inside the common block.  */
-  union_type = make_node (UNION_TYPE);
+  /* Declare the variables inside the common block.
+     If the current common block contains any equivalence object, then
+     make a UNION_TYPE node, otherwise RECORD_TYPE. This will let the
+     alias analyzer work well when there is no address overlapping for
+     common variables in the current common block.  */
+  if (saw_equiv)
+    union_type = make_node (UNION_TYPE);
+  else
+    union_type = make_node (RECORD_TYPE);
+
   rli = start_record_layout (union_type);
   field_link = &TYPE_FIELDS (union_type);
 
@@ -703,7 +711,7 @@ find_equivalence (segment_info *n)
    segment list multiple times to include indirect equivalences.  */
 
 static void
-add_equivalences (void)
+add_equivalences (bool *saw_equiv)
 {
   segment_info *f;
   bool more;
@@ -718,6 +726,8 @@ add_equivalences (void)
            {
              f->sym->equiv_built = 1;
              more = find_equivalence (f);
+             if (more)
+               *saw_equiv = true;
            }
        }
     }
@@ -788,10 +798,12 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
   HOST_WIDE_INT current_offset;
   unsigned HOST_WIDE_INT align;
   unsigned HOST_WIDE_INT max_align;
+  bool saw_equiv;
 
   common_segment = NULL;
   current_offset = 0;
   max_align = 1;
+  saw_equiv = false;
 
   /* Add symbols to the segment.  */
   for (sym = var_list; sym; sym = sym->common_next)
@@ -821,7 +833,7 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
 
          /* Add all objects directly or indirectly equivalenced with this
             symbol.  */
-         add_equivalences ();
+         add_equivalences (&saw_equiv);
 
          if (current_segment->offset < 0)
            gfc_error ("The equivalence set for '%s' cause an invalid "
@@ -865,7 +877,7 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
                   common->name, &common->where, common_segment->offset);
     }
 
-  create_common (common, common_segment);
+  create_common (common, common_segment, saw_equiv);
 }
 
 
@@ -878,6 +890,7 @@ finish_equivalences (gfc_namespace *ns)
   gfc_symbol *sym;
   HOST_WIDE_INT offset;
   unsigned HOST_WIDE_INT align;
+  bool dummy;
 
   for (z = ns->equiv; z; z = z->next)
     for (y = z->eq; y; y = y->eq)
@@ -888,7 +901,7 @@ finish_equivalences (gfc_namespace *ns)
         current_segment = get_segment_info (sym, 0);
 
         /* All objects directly or indirectly equivalenced with this symbol.  */
-        add_equivalences ();
+        add_equivalences (&dummy);
 
        /* Align the block.  */
        offset = align_segment (&align);
@@ -899,7 +912,7 @@ finish_equivalences (gfc_namespace *ns)
        apply_segment_offset (current_segment, offset);
 
        /* Create the decl.  */
-        create_common (NULL, current_segment);
+        create_common (NULL, current_segment, true);
         break;
       }
 }