re PR middle-end/89655 (GCC crashes building linux kernel for arm 32-bit (culprit r269453))

	PR middle-end/89655
	PR bootstrap/89656
	* vr-values.c (vr_values::update_value_range): If
	old_vr->varying_p (), don't update it, make new_vr also VARYING
	and return false.

	* gcc.c-torture/compile/pr89655.c: New test.

From-SVN: r269597

gcc/ChangeLog

+2019-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/89655
+	PR bootstrap/89656
+	* vr-values.c (vr_values::update_value_range): If
+	old_vr->varying_p (), don't update it, make new_vr also VARYING
+	and return false.
+
 2019-03-11  Martin Liska  <mliska@suse.cz>
 
 	* config/aarch64/aarch64.c (aarch64_override_options_internal):

gcc/testsuite/ChangeLog

+2019-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/89655
+	PR bootstrap/89656
+	* gcc.c-torture/compile/pr89655.c: New test.
+
 2019-03-11  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.target/arm/f16_f64_conv_no_dp.c: Add arm_fp16_ok effective

gcc/testsuite/gcc.c-torture/compile/pr89655.c

+/* PR middle-end/89655 */
+
+int a, b, d;
+char *c;
+
+void
+foo (void)
+{
+  int f = a;
+  for (;;)
+    {
+      for (f = 0; f < (a > 3 ? : a); f++)
+	b = c[f] ? c[(f + 2 > a - 1 ? a - 1 : 2) * d] : 0;
+    }
+}

gcc/vr-values.c

@@ -189,8 +189,13 @@ vr_values::update_value_range (const_tree var, value_range *new_vr)
 	 because VR_RANGE and VR_ANTI_RANGE need to be considered
 	 the same.  We may not have is_new when transitioning to
 	 UNDEFINED.  If old_vr->type is VARYING, we shouldn't be
-	 called.  */
-      if (new_vr->undefined_p ())
+	 called, if we are anyway, keep it VARYING.  */
+      if (old_vr->varying_p ())
+	{
+	  new_vr->set_varying ();
+	  is_new = false;
+	}
+      else if (new_vr->undefined_p ())
 	{
 	  old_vr->set_varying ();
 	  new_vr->set_varying ();