re PR tree-optimization/19121 (ICE: in merge_alias_info, at tree-ssa-copy.c:236)

	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.

From-SVN: r93810

gcc/ChangeLog

+2005-01-17  Diego Novillo  <dnovillo@redhat.com>
+
+	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.
+
 2005-01-17  James E Wilson  <wilson@specifixinc.com>
 
 	PR target/19357

gcc/testsuite/ChangeLog

+2005-01-17  Diego Novillo  <dnovillo@redhat.com>
+
+	PR tree-optimization/19121
+	* gcc.c-torture/compile/pr19121.c: New test.
+
 2005-01-17  James E. Wilson  <wilson@specifixinc.com>
 
 	PR target/19357

gcc/testsuite/gcc.c-torture/compile/pr19121.c

+typedef struct interpreter {
+  char Itokenbuf[256];
+} PerlInterpreter;
+static inline void S_missingterm(char *s)
+{
+  char tmpbuf[3] = "";
+  char q;
+  if (!s)
+    s = tmpbuf;
+  q = strchr(s,'"') ? '\'' : '"';
+}
+void S_scan_heredoc(PerlInterpreter *my_perl, char *s, int i)
+{
+  char term;
+  term = *my_perl->Itokenbuf;
+  if (i)
+  {
+    *s = term;
+    S_missingterm(my_perl->Itokenbuf);
+  }
+  else
+    S_missingterm(my_perl->Itokenbuf);
+}

gcc/tree-ssa-alias.c

@@ -913,6 +913,7 @@ compute_flow_sensitive_aliasing (struct alias_info *ai)
 	EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, j, bi)
 	  {
 	    add_may_alias (pi->name_mem_tag, referenced_var (j));
+	    add_may_alias (v_ann->type_mem_tag, referenced_var (j));
 	  }
 
       /* If the name tag is call clobbered, so is the type tag

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)
+#if defined ENABLE_CHECKING
   {
-      struct ptr_info_def *new_ptr_info = get_ptr_info (new);
-
-      if (new_ptr_info->name_mem_tag == NULL_TREE)
+    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)
     {
-	  /* 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)
+      /* 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
     }
   }
+#endif
 }   
 
 

gcc/tree-ssa.c

@@ -469,7 +469,11 @@ DEF_VEC_MALLOC_P (bitmap);
    same name tag must have the same points-to set. 
    So we check a single variable for each name tag, and verify that its
    points-to set is different from every other points-to set for other name
-   tags.  */
+   tags.
+
+   Additionally, given a pointer P_i with name tag NMT and type tag
+   TMT, this function verified the alias set of TMT is a superset of
+   the alias set of NMT.  */
 
 static void
 verify_name_tags (void)
@@ -479,25 +483,62 @@ verify_name_tags (void)
   bitmap first, second;  
   VEC (tree) *name_tag_reps = NULL;
   VEC (bitmap) *pt_vars_for_reps = NULL;
+  bitmap type_aliases = BITMAP_XMALLOC ();
 
   /* First we compute the name tag representatives and their points-to sets.  */
   for (i = 0; i < num_ssa_names; i++)
     {
-      if (ssa_name (i))
-	{
-	  tree ptr = ssa_name (i);
-	  struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+      struct ptr_info_def *pi;
+      tree tmt, ptr = ssa_name (i);
+
+      if (ptr == NULL_TREE)
+	continue;
+      
+      pi = SSA_NAME_PTR_INFO (ptr);
+
       if (!TREE_VISITED (ptr) 
 	  || !POINTER_TYPE_P (TREE_TYPE (ptr)) 
 	  || !pi
 	  || !pi->name_mem_tag 
 	  || TREE_VISITED (pi->name_mem_tag))
 	continue;
+
       TREE_VISITED (pi->name_mem_tag) = 1;
-	  if (pi->pt_vars != NULL)
-	    {    
+
+      if (pi->pt_vars == NULL)
+	continue;
+
       VEC_safe_push (tree, name_tag_reps, ptr);
       VEC_safe_push (bitmap, pt_vars_for_reps, pi->pt_vars);
+
+      /* Verify that alias set of PTR's type tag is a superset of the
+	 alias set of PTR's name tag.  */
+      tmt = var_ann (SSA_NAME_VAR (ptr))->type_mem_tag;
+      if (tmt)
+	{
+	  size_t i;
+	  varray_type aliases = var_ann (tmt)->may_aliases;
+	  bitmap_clear (type_aliases);
+	  for (i = 0; aliases && i < VARRAY_ACTIVE_SIZE (aliases); i++)
+	    {
+	      tree alias = VARRAY_TREE (aliases, i);
+	      bitmap_set_bit (type_aliases, var_ann (alias)->uid);
+	    }
+
+	  /* When grouping, we may have added PTR's type tag into the
+	     alias set of PTR's name tag.  To prevent a false
+	     positive, pretend that TMT is in its own alias set.  */
+	  bitmap_set_bit (type_aliases, var_ann (tmt)->uid);
+
+	  if (bitmap_equal_p (type_aliases, pi->pt_vars))
+	    continue;
+
+	  if (!bitmap_intersect_compl_p (type_aliases, pi->pt_vars))
+	    {
+	      error ("Alias set of a pointer's type tag should be a superset of the corresponding name tag");
+	      debug_variable (tmt);
+	      debug_variable (pi->name_mem_tag);
+	      goto err;
 	    }
 	}
     }
@@ -532,13 +573,17 @@ verify_name_tags (void)
 	  TREE_VISITED (pi->name_mem_tag) = 0;
 	}
     } 
+
   VEC_free (bitmap, pt_vars_for_reps);
+  BITMAP_FREE (type_aliases);
   return;
   
 err:
   debug_variable (VEC_index (tree, name_tag_reps, i));
   internal_error ("verify_name_tags failed");
 }
+
+
 /* Verify the consistency of aliasing information.  */
 
 static void