re PR tree-optimization/16688 (ICE in group_aliases, at tree-ssa-alias.c:1234)

	PR tree-optimization/16688
	PR tree-optimization/16689
	* tree-ssa-alias.c (setup_pointers_and_addressables): Remove
	unnecessary initialization of 'tag'.
	(get_tmt_for): Check that the new type tag has the same alias
	set as the pointed-to type.
	(group_aliases): Only regular variables need to be removed
	from the alias set of a name tag.
	* tree-ssa-copy.c (may_propagate_copy): Do not allow copy
	propagation if the two types are not compatible.
	(merge_alias_info): Rename from replace_ssa_names_ann.
	Add more checking.
	(replace_exp_1): If both arguments are SSA_NAMEs, check that
	the propagation can be done.
	Only call merge_alias_info on pointers.
	(propagate_value): Likewise.
	* tree-ssa-copyrename.c: Include langhooks.h.
	(copy_rename_partition_coalesce): Call replace_ssa_name_symbol
	to do the merging.
	Do not coalesce variables with incompatible types.
	(rename_ssa_copies): Call replace_ssa_name_symbol.
	* tree-ssa.c (verify_ssa_name): Verify that the SSA_NAME has
	the same type as the underlying _DECL.
	* tree-ssanames.c (replace_ssa_name_symbol): New function.
	* tree.h (replace_ssa_name_symbol): Declare.

From-SVN: r85108

gcc/ChangeLog

+2004-07-23  Diego Novillo  <dnovillo@redhat.com>
+
+	PR tree-optimization/16688
+	PR tree-optimization/16689
+	* tree-ssa-alias.c (setup_pointers_and_addressables): Remove
+	unnecessary initialization of 'tag'.
+	(get_tmt_for): Check that the new type tag has the same alias
+	set as the pointed-to type.
+	(group_aliases): Only regular variables need to be removed
+	from the alias set of a name tag.
+	* tree-ssa-copy.c (may_propagate_copy): Do not allow copy
+	propagation if the two types are not compatible.
+	(merge_alias_info): Rename from replace_ssa_names_ann.
+	Add more checking.
+	(replace_exp_1): If both arguments are SSA_NAMEs, check that
+	the propagation can be done.
+	Only call merge_alias_info on pointers.
+	(propagate_value): Likewise.
+	* tree-ssa-copyrename.c: Include langhooks.h.
+	(copy_rename_partition_coalesce): Call replace_ssa_name_symbol
+	to do the merging.
+	Do not coalesce variables with incompatible types.
+	(rename_ssa_copies): Call replace_ssa_name_symbol.
+	* tree-ssa.c (verify_ssa_name): Verify that the SSA_NAME has
+	the same type as the underlying _DECL.
+	* tree-ssanames.c (replace_ssa_name_symbol): New function.
+	* tree.h (replace_ssa_name_symbol): Declare.
+
 2004-07-23  Richard Henderson  <rth@redhat.com>
 
 	PR c++/16277

gcc/tree-ssa-alias.c

@@ -1225,7 +1225,8 @@ group_aliases (struct alias_info *ai)
 	{
 	  tree alias = VARRAY_TREE (aliases, j);
 	  var_ann_t ann = var_ann (alias);
-	  if (ann->may_aliases)
+
+	  if (ann->mem_tag_kind == NOT_A_TAG && ann->may_aliases)
 	    {
 	      tree new_alias;
 
@@ -1370,7 +1371,7 @@ setup_pointers_and_addressables (struct alias_info *ai)
 	  && (bitmap_bit_p (ai->dereferenced_ptrs_store, v_ann->uid)
 	      || bitmap_bit_p (ai->dereferenced_ptrs_load, v_ann->uid)))
 	{
-	  tree tag = v_ann->type_mem_tag;
+	  tree tag;
 	  var_ann_t t_ann;
 
 	  /* If pointer VAR still doesn't have a memory tag associated
@@ -2170,6 +2171,14 @@ get_tmt_for (tree ptr, struct alias_info *ai)
       ai->pointers[ai->num_pointers++] = alias_map;
     }
 
+#if defined ENABLE_CHECKING
+  /* Make sure that the type tag has the same alias set as the
+     pointed-to type.  */
+  if (tag_set != get_alias_set (tag))
+    abort ();
+#endif
+
+
   return tag;
 }
 

gcc/tree-ssa-copy.c

@@ -110,6 +110,8 @@ may_propagate_copy (tree dest, tree orig)
       tree mt_orig = var_ann (SSA_NAME_VAR (orig))->type_mem_tag;
       if (mt_dest && mt_orig && mt_dest != mt_orig)
 	return false;
+      else if (!lang_hooks.types_compatible_p (type_d, type_o))
+	return false;
     }
 
   /* If the destination is a SSA_NAME for a virtual operand, then we have
@@ -152,41 +154,40 @@ may_propagate_copy (tree dest, tree orig)
   return true;
 }
 
-/* Given two SSA_NAMEs, replace the annotations for the one referred to by OP 
-   with VAR's annotations.
-
-   If OP is a pointer, copy the memory tag used originally by OP into
-   VAR.  This is needed in cases where VAR had never been dereferenced in the
-   program.
 
-   If FOR_PROPAGATION is true, then perform additional checks to ensure
-   that const/copy propagation of var for OP is valid.  */
+/* Given two SSA_NAMEs pointers ORIG and NEW such that we are copy
+   propagating NEW into ORIG, consolidate aliasing information so that
+   they both share the same memory tags.  */
    
 static void
-replace_ssa_names_ann (tree op,
-		   tree var,
-		   bool for_propagation ATTRIBUTE_UNUSED)
+merge_alias_info (tree orig, tree new)
 {
+  tree new_sym = SSA_NAME_VAR (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);
+
 #if defined ENABLE_CHECKING
-  if (for_propagation && !may_propagate_copy (op, var))
+  if (!POINTER_TYPE_P (TREE_TYPE (orig))
+      || !POINTER_TYPE_P (TREE_TYPE (new))
+      || !lang_hooks.types_compatible_p (TREE_TYPE (orig), TREE_TYPE (new)))
     abort ();
-#endif
 
-  /* If VAR doesn't have a memory tag, copy the one from the original
-     operand.  Also copy the dereferenced flags.  */
-  if (POINTER_TYPE_P (TREE_TYPE (op)))
-    {
-      var_ann_t new_ann = var_ann (SSA_NAME_VAR (var));
-      var_ann_t orig_ann = var_ann (SSA_NAME_VAR (op));
-
-      if (new_ann->type_mem_tag == NULL_TREE)
-	new_ann->type_mem_tag = orig_ann->type_mem_tag;
-      else if (orig_ann->type_mem_tag == NULL_TREE)
-	orig_ann->type_mem_tag = new_ann->type_mem_tag;
-      else if (new_ann->type_mem_tag != orig_ann->type_mem_tag)
-	abort ();
-    }
+  /* If the pointed-to alias sets are different, these two pointers
+     would never have the same memory tag.  In this case, NEW should
+     not have been propagated into ORIG.  */
+  if (get_alias_set (TREE_TYPE (TREE_TYPE (new_sym)))
+      != get_alias_set (TREE_TYPE (TREE_TYPE (orig_sym))))
+    abort ();
+#endif
 
+  /* Merge type-based alias info.  */
+  if (new_ann->type_mem_tag == NULL_TREE)
+    new_ann->type_mem_tag = orig_ann->type_mem_tag;
+  else if (orig_ann->type_mem_tag == NULL_TREE)
+    orig_ann->type_mem_tag = new_ann->type_mem_tag;
+  else if (new_ann->type_mem_tag != orig_ann->type_mem_tag)
+    abort ();
 }   
 
 
@@ -196,12 +197,23 @@ replace_ssa_names_ann (tree op,
    replacement is done to propagate a value or not.  */
 
 static void
-replace_exp_1 (use_operand_p op_p, tree val, bool for_propagation)
+replace_exp_1 (use_operand_p op_p, tree val,
+	       bool for_propagation ATTRIBUTE_UNUSED)
 {
+  tree op = USE_FROM_PTR (op_p);
+
+#if defined ENABLE_CHECKING
+  if (for_propagation
+      && TREE_CODE (op) == SSA_NAME
+      && TREE_CODE (val) == SSA_NAME
+      && !may_propagate_copy (op, val))
+    abort ();
+#endif
+
   if (TREE_CODE (val) == SSA_NAME)
     {
-      if (TREE_CODE (USE_FROM_PTR (op_p)) == SSA_NAME)
-	replace_ssa_names_ann (USE_FROM_PTR (op_p), val, for_propagation);
+      if (TREE_CODE (op) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (op)))
+	merge_alias_info (op, val);
       SET_USE (op_p, val);
     }
   else
@@ -233,10 +245,17 @@ propagate_value (use_operand_p op_p, tree val)
 void
 propagate_tree_value (tree *op_p, tree val)
 {
+#if defined ENABLE_CHECKING
+  if (TREE_CODE (val) == SSA_NAME
+      && TREE_CODE (*op_p) == SSA_NAME
+      && !may_propagate_copy (*op_p, val))
+    abort ();
+#endif
+
   if (TREE_CODE (val) == SSA_NAME)
     {
-      if (TREE_CODE (*op_p) == SSA_NAME)
-	replace_ssa_names_ann (*op_p, val, true);
+      if (TREE_CODE (*op_p) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (*op_p)))
+	merge_alias_info (*op_p, val);
       *op_p = val;
     }
   else

gcc/tree-ssa-copyrename.c

@@ -38,6 +38,7 @@ Boston, MA 02111-1307, USA.  */
 #include "tree-dump.h"
 #include "tree-ssa-live.h"
 #include "tree-pass.h"
+#include "langhooks.h"
 
 extern void rename_ssa_copies (void);
 
@@ -247,16 +248,24 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
 	gimp2 = false;
       }
 
+  /* Don't coalesce if the two variables aren't type compatible.  */
+  if (!lang_hooks.types_compatible_p (TREE_TYPE (root1), TREE_TYPE (root2)))
+    {
+      if (debug)
+	fprintf (debug, " : Incompatible types.  No coalesce.\n");
+      return;
+    }
+
   /* Merge the two partitions.  */
   p3 = partition_union (map->var_partition, p1, p2);
 
   /* Set the root variable of the partition to the better choice, if there is 
      one.  */
   if (!gimp2)
-    SSA_NAME_VAR (partition_to_var (map, p3)) = root2;
+    replace_ssa_name_symbol (partition_to_var (map, p3), root2);
   else
     if (!gimp1)
-      SSA_NAME_VAR (partition_to_var (map, p3)) = root1;
+      replace_ssa_name_symbol (partition_to_var (map, p3), root1);
 
   /* Update the various flag widgitry of the current base representative.  */
   ann3 = var_ann (SSA_NAME_VAR (partition_to_var (map, p3)));
@@ -359,7 +368,7 @@ rename_ssa_copies (void)
 	      fprintf (debug, "\n");
 	    }
 	}
-      SSA_NAME_VAR (var) = SSA_NAME_VAR (part_var);
+      replace_ssa_name_symbol (var, SSA_NAME_VAR (part_var));
     }
 
   delete_var_map (map);

gcc/tree-ssa.c

@@ -118,6 +118,12 @@ verify_ssa_name (tree ssa_name, bool is_virtual)
       return true;
     }
 
+  if (TREE_TYPE (ssa_name) != TREE_TYPE (SSA_NAME_VAR (ssa_name)))
+    {
+      error ("Type mismatch between an SSA_NAME and its symbol.");
+      return true;
+    }
+
   if (SSA_NAME_IN_FREE_LIST (ssa_name))
     {
       error ("Found an SSA_NAME that had been released into the free pool");

gcc/tree-ssanames.c

@@ -249,4 +249,14 @@ release_defs (tree stmt)
     release_ssa_name (V_MUST_DEF_OP (v_must_defs, i));
 }
 
+
+/* Replace the symbol associated with SSA_NAME with SYM.  */
+
+void
+replace_ssa_name_symbol (tree ssa_name, tree sym)
+{
+  SSA_NAME_VAR (ssa_name) = sym;
+  TREE_TYPE (ssa_name) = TREE_TYPE (sym);
+}
+
 #include "gt-tree-ssanames.h"

gcc/tree.h

@@ -2648,6 +2648,7 @@ extern tree make_ssa_name (tree, tree);
 extern tree duplicate_ssa_name (tree, tree);
 extern void release_ssa_name (tree);
 extern void release_defs (tree);
+extern void replace_ssa_name_symbol (tree, tree);
 
 #ifdef GATHER_STATISTICS
 extern void ssanames_print_statistics (void);