re PR middle-end/38572 (ICE in set_value_range, at tree-vrp.c:398)

2008-12-30  Paolo Bonzini  <bonzini@gnu.org>

	PR tree-optimization/38572
	* tree-vrp.c (vrp_visit_phi_node): Look out for invalid ranges
	and change them to VARYING.

From-SVN: r142962

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1772b608765dc1e122a5480dbc154c741d36cf93..5c3789a2a820bc1a03f7d72909981af9f3c76598 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2008-12-30  Paolo Bonzini  <bonzini@gnu.org>
+
+       PR tree-optimization/38572
+       * tree-vrp.c (vrp_visit_phi_node): Look out for invalid ranges
+       and change them to VARYING.
+
 2008-12-30  Richard Guenther  <rguenther@suse.de>
 
        PR middle-end/38564

diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr38572.C b/gcc/testsuite/g++.dg/tree-ssa/pr38572.C
new file mode 100644 (file)
index 0000000..89d228f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr38572.C
@@ -0,0 +1,32 @@
+// PR tree-optimization/38572
+// { dg-do compile }
+// { dg-options "-O2" }
+
+// Crash caused by the out-of-bounds enum values (all the remaining cruft
+// is needed only to trigger the appropriate code path in tree-vrp.c).
+enum JSOp
+{
+  JSOP_GETELEM = 5,
+  JSOP_LIMIT
+};
+extern void g ();
+void f (char *pc, char *endpc, int format, char ***fp, enum JSOp op)
+{
+  while (pc <= endpc)
+    {
+      if ((fp && *fp && pc == **fp) || pc == endpc)
+       {
+         if (format == 1)
+           op = (JSOp) 256;
+         else if (format == 2)
+           op = (JSOp) 257;
+         else
+           op = JSOP_GETELEM;
+       }
+      if (op >= JSOP_LIMIT)
+       {
+         if (format)
+           g ();
+       }
+    }
+}

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 9d23b24087f1d5acf7c28e9fe8558361d1778d8b..4b6caca1c37452b65d5335b594159442e7b29f26 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -6361,9 +6361,12 @@ vrp_visit_phi_node (gimple phi)
             minimums.  */
          if (cmp_min > 0 || cmp_min < 0)
            {
-             /* If we will end up with a (-INF, +INF) range, set it
-                to VARYING.  */
-             if (vrp_val_is_max (vr_result.max))
+             /* If we will end up with a (-INF, +INF) range, set it to
+                VARYING.  Same if the previous max value was invalid for
+                the type and we'd end up with vr_result.min > vr_result.max.  */
+             if (vrp_val_is_max (vr_result.max)
+                 || compare_values (TYPE_MIN_VALUE (TREE_TYPE (vr_result.min)),
+                                    vr_result.max) > 0)
                goto varying;
 
              if (!needs_overflow_infinity (TREE_TYPE (vr_result.min))
@@ -6380,9 +6383,12 @@ vrp_visit_phi_node (gimple phi)
             the previous one, go all the way to +INF.  */
          if (cmp_max < 0 || cmp_max > 0)
            {
-             /* If we will end up with a (-INF, +INF) range, set it
-                to VARYING.  */
-             if (vrp_val_is_min (vr_result.min))
+             /* If we will end up with a (-INF, +INF) range, set it to
+                VARYING.  Same if the previous min value was invalid for
+                the type and we'd end up with vr_result.max < vr_result.min.  */
+             if (vrp_val_is_min (vr_result.min)
+                 || compare_values (TYPE_MAX_VALUE (TREE_TYPE (vr_result.max)),
+                                    vr_result.min) < 0)
                goto varying;
 
              if (!needs_overflow_infinity (TREE_TYPE (vr_result.max))