PR tree-optimization/19121

	* tree-ssa-alias.c (compute_flow_sensitive_aliasing): When
	adding aliases to a name tag, also add them to the pointer's
	type tag.
	* tree-ssa-copy.c (merge_alias_info): Do not merge flow
	sensitive alias info at all.  Only check that the two pointers
	have compatible pointed-to sets.
	* tree-ssa.c (verify_name_tags): Verify that the alias set of
	a pointer's type tag is a superset of the alias set of the
	pointer's name tag.

testsuite/ChangeLog:

	PR tree-optimization/19121
	* gcc.c-torture/compile/pr19121.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@93810 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 23 insertions, 34 deletions

diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c
index 8a03c2435d1..c679eb221be 100644
--- a/gcc/tree-ssa-copy.c
+++ b/gcc/tree-ssa-copy.c
@@ -178,10 +178,10 @@ merge_alias_info (tree orig, tree new)
   tree orig_sym = SSA_NAME_VAR (orig);
   var_ann_t new_ann = var_ann (new_sym);
   var_ann_t orig_ann = var_ann (orig_sym);
-  struct ptr_info_def *orig_ptr_info;
 
   gcc_assert (POINTER_TYPE_P (TREE_TYPE (orig)));
   gcc_assert (POINTER_TYPE_P (TREE_TYPE (new)));
+
 #if defined ENABLE_CHECKING
   gcc_assert (lang_hooks.types_compatible_p (TREE_TYPE (orig),
 					     TREE_TYPE (new)));
@@ -202,41 +202,30 @@ merge_alias_info (tree orig, tree new)
   else
     gcc_assert (new_ann->type_mem_tag == orig_ann->type_mem_tag);
 
-  orig_ptr_info = SSA_NAME_PTR_INFO (orig);
-  if (orig_ptr_info && orig_ptr_info->name_mem_tag)
-    {
-      struct ptr_info_def *new_ptr_info = get_ptr_info (new);
-
-      if (new_ptr_info->name_mem_tag == NULL_TREE)
-	{
-	  /* If ORIG had a name tag, it means that was dereferenced in
-	     the code, and since pointer NEW will now replace every
-	     occurrence of ORIG, we have to make sure that NEW has an
-	     appropriate tag.  If, NEW did not have a name tag, get it
-	     from ORIG.  */
-	  memcpy (new_ptr_info, orig_ptr_info, sizeof (*new_ptr_info));
-	  new_ptr_info->pt_vars = BITMAP_GGC_ALLOC ();
-	  bitmap_copy (new_ptr_info->pt_vars, orig_ptr_info->pt_vars);
-	  new_ptr_info->name_mem_tag = orig_ptr_info->name_mem_tag;
-	}
-      else
-	{
-	  /* If NEW already had a name tag, nothing needs to be done.
-	     Note that pointer NEW may actually have a different set of
-	     pointed-to variables.
-	     
-	     However, since NEW is being copy-propagated into ORIG, it must
-	     always be true that the pointed-to set for pointer NEW is the
-	     same, or a subset, of the pointed-to set for pointer ORIG.  If
-	     this isn't the case, we shouldn't have been able to do the
-	     propagation of NEW into ORIG.  */
 #if defined ENABLE_CHECKING
-	  if (orig_ptr_info->pt_vars && new_ptr_info->pt_vars)
-	    gcc_assert (bitmap_intersect_p (new_ptr_info->pt_vars,
-					    orig_ptr_info->pt_vars));
-#endif
-	}
+  {
+    struct ptr_info_def *orig_ptr_info = SSA_NAME_PTR_INFO (orig);
+    struct ptr_info_def *new_ptr_info = SSA_NAME_PTR_INFO (new);
+
+    if (orig_ptr_info
+	&& new_ptr_info
+	&& orig_ptr_info->name_mem_tag
+	&& new_ptr_info->name_mem_tag
+	&& orig_ptr_info->pt_vars
+	&& new_ptr_info->pt_vars)
+    {
+      /* Note that pointer NEW may actually have a different set of
+	 pointed-to variables.  However, since NEW is being
+	 copy-propagated into ORIG, it must always be true that the
+	 pointed-to set for pointer NEW is the same, or a subset, of
+	 the pointed-to set for pointer ORIG.  If this isn't the case,
+	 we shouldn't have been able to do the propagation of NEW into
+	 ORIG.  */
+      gcc_assert (bitmap_intersect_p (new_ptr_info->pt_vars,
+				      orig_ptr_info->pt_vars));
     }
+  }
+#endif
 }