re PR c++/23046 (ICE in set_value_range, at tree-vrp.c:191)

2005-11-08  James A. Morrison  <phython@gcc.gnu.org>
	    Diego Novillo  <dnovillo@redhat.com>

	PR 23046
	* tree-vrp.c (register_edge_assert_for): Do not register
	always-false predicates.

testsuite/

	PR 23046
	* g++.dg/tree-ssa/pr23046.C: New test.

From-SVN: r106656

gcc/ChangeLog

+2005-11-08  James A. Morrison  <phython@gcc.gnu.org>
+	    Diego Novillo  <dnovillo@redhat.com>
+
+	PR 23046
+	* tree-vrp.c (register_edge_assert_for): Do not register
+	always-false predicates.
+
 2005-11-08  Devang Patel <dpatel@apple.com>
 
 	PR tree-optimization/23115

gcc/testsuite/ChangeLog

+2005-11-08  Diego Novillo  <dnovillo@redhat.com>
+
+	PR 23046
+	* g++.dg/tree-ssa/pr23046.C: New test.
+
 2005-11-08  Devang Patel <dpatel@apple.com>
 
 	PR tree-optimization/23115

gcc/testsuite/g++.dg/tree-ssa/pr23046.C

+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+enum eumtype { ENUM1, ENUM2 };
+void g(const eumtype kind );
+void f(long i);
+void g(const eumtype kind)
+{
+  if ((kind != ENUM1) && (kind != ENUM2))
+    f(kind);
+}

gcc/tree-vrp.c

@@ -2504,6 +2504,24 @@ register_edge_assert_for (tree name, edge e, block_stmt_iterator si)
 	     need to invert the sign comparison.  */
 	  if (is_else_edge)
 	    comp_code = invert_tree_comparison (comp_code, 0);
+
+	  /* Do not register always-false predicates.  FIXME, this
+	     works around a limitation in fold() when dealing with
+	     enumerations.  Given 'enum { N1, N2 } x;', fold will not
+	     fold 'if (x > N2)' to 'if (0)'.  */
+	  if ((comp_code == GT_EXPR || comp_code == LT_EXPR)
+	      && (INTEGRAL_TYPE_P (TREE_TYPE (val))
+		  || SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))))
+	    {
+	      tree min = TYPE_MIN_VALUE (TREE_TYPE (val));
+	      tree max = TYPE_MAX_VALUE (TREE_TYPE (val));
+
+	      if (comp_code == GT_EXPR && compare_values (val, max) == 0)
+		return false;
+
+	      if (comp_code == LT_EXPR && compare_values (val, min) == 0)
+		return false;
+	    }
 	}
     }
   else