re PR tree-optimization/54317 (FAIL: c45532m c45532n c45532o c45532p)

2012-08-22  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/54317

gcc/
	* tree-vrp.c (extract_range_from_binary_expr_1): Test for
	double_int overflow.
	Remove dead tests.

gcc/testsuite/
	* gcc.dg/tree-ssa/vrp79.c: New testcase.

From-SVN: r190591

gcc/ChangeLog

+2012-08-22  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/54317
+	* tree-vrp.c (extract_range_from_binary_expr_1): Test for
+	double_int overflow.
+	Remove dead tests.
+
 2012-08-22  Jakub Jelinek  <jakub@redhat.com>
 
 	* tree-vrp.c (find_assert_locations): Skip also edges

gcc/testsuite/ChangeLog

+2012-08-22  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/54317
+	* gcc.dg/tree-ssa/vrp79.c: New testcase.
+
 2012-08-21  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	PR target/39423

gcc/testsuite/gcc.dg/tree-ssa/vrp79.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+#ifdef __SIZEOF_INT128__
+typedef unsigned __int128 NT;
+#else
+typedef unsigned long long NT;
+#endif
+
+extern void do_not_go_away ();
+
+void f (NT x, NT y)
+{
+  NT n = 1;
+  n <<= (__CHAR_BIT__ * sizeof (NT) - 1);
+  if (x > n) return;
+  if (y > n) return;
+  NT z = x + y;
+  if (z == 42) do_not_go_away ();
+}
+
+/* { dg-final { scan-tree-dump "do_not_go_away" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/tree-vrp.c

@@ -2474,18 +2474,21 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
 		{
 		  /* Min underflow or max overflow.  The range kind
 		     changes to VR_ANTI_RANGE.  */
+		  bool covers = false;
 		  double_int tem = tmin;
 		  gcc_assert ((min_ovf == -1 && max_ovf == 0)
 			      || (max_ovf == 1 && min_ovf == 0));
 		  type = VR_ANTI_RANGE;
 		  tmin = double_int_add (tmax, double_int_one);
+		  if (double_int_cmp (tmin, tmax, uns) < 0)
+		    covers = true;
 		  tmax = double_int_add (tem, double_int_minus_one);
+		  if (double_int_cmp (tmax, tem, uns) > 0)
+		    covers = true;
 		  /* If the anti-range would cover nothing, drop to varying.
 		     Likewise if the anti-range bounds are outside of the
 		     types values.  */
-		  if (double_int_cmp (tmin, tmax, uns) > 0
-		      || double_int_cmp (tmin, type_min, uns) < 0
-		      || double_int_cmp (tmax, type_max, uns) > 0)
+		  if (covers || double_int_cmp (tmin, tmax, uns) > 0)
 		    {
 		      set_value_range_to_varying (vr);
 		      return;