re PR tree-optimization/34138 (verify_ssa failed (found real variable when…

re PR tree-optimization/34138 (verify_ssa failed (found real variable when subvariables should have appeared))

2007-12-05  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/34138
	* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
	Do not forward propagate addresses if that changes volatileness of
	the pointed-to type.

	* gcc.c-torture/compile/pr34138.c: New testcase.

From-SVN: r130632

gcc/ChangeLog

+2007-12-05  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/34138
+	* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
+	Do not forward propagate addresses if that changes volatileness of
+	the pointed-to type.
+
 2007-12-05  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/34312

gcc/testsuite/ChangeLog

+2007-12-05  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/34138
+	* gcc.c-torture/compile/pr34138.c: New testcase.
+
 2007-12-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/33739

gcc/testsuite/gcc.c-torture/compile/pr34138.c

+extern void free (void *__ptr);
+struct shparam
+{
+  char **p;
+  int foo;
+};
+static struct shparam shellparam;
+inline void freeparam (volatile struct shparam *param, char **ap)
+{
+  free ((void *) (*ap));
+  free ((void *) (param->p));
+}
+void dotcmd (char **p)
+{
+  freeparam (&shellparam, p);
+}
+void evaltree (void)
+{
+  void (*evalfn) (char **);
+  evalfn = dotcmd;
+}

gcc/tree-ssa-forwprop.c

@@ -956,12 +956,15 @@ tree_ssa_forward_propagate_single_use_vars (void)
 		}
 
 	      if (TREE_CODE (rhs) == ADDR_EXPR
-		  /* We can also disregard changes in CV qualifiers for
+		  /* We can also disregard changes in const qualifiers for
 		     the dereferenced value.  */
 		  || ((TREE_CODE (rhs) == NOP_EXPR
 		       || TREE_CODE (rhs) == CONVERT_EXPR)
 		      && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
 		      && POINTER_TYPE_P (TREE_TYPE (rhs))
+		      /* But do not propagate changes in volatileness.  */
+		      && (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (rhs)))
+			  == TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (rhs, 0)))))
 		      && types_compatible_p (TREE_TYPE (TREE_TYPE (TREE_OPERAND (rhs, 0))),
 					     TREE_TYPE (TREE_TYPE (rhs)))))
 		{