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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@190591 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 88ec752..c04f5cb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+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

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6724380..049e2d1 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+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

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp79.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp79.c
new file mode 100644 (file)
index 0000000..88c1bd8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp79.c
@@ -0,0 +1,23 @@
+/* { 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" } } */

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 0aa1dc7..f949e8b 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/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;