8215044: C2 crash in loopTransform.cpp with assert(cl->trip_count() > 0) failed: peeling a fully unrolled loop
authorroland
Thu, 13 Dec 2018 17:57:11 +0100
changeset 53167 030429d6baac
parent 53166 36e4c704a88d
child 53168 f019e5a7b118
8215044: C2 crash in loopTransform.cpp with assert(cl->trip_count() > 0) failed: peeling a fully unrolled loop Reviewed-by: thartmann, kvn
src/hotspot/share/opto/loopTransform.cpp
test/hotspot/jtreg/compiler/loopopts/PeelingZeroTripCount.java
--- a/src/hotspot/share/opto/loopTransform.cpp	Thu Jan 03 11:21:11 2019 +0530
+++ b/src/hotspot/share/opto/loopTransform.cpp	Thu Dec 13 17:57:11 2018 +0100
@@ -354,6 +354,10 @@
   // check for vectorized loops, any peeling done was already applied
   if (_head->is_CountedLoop() && _head->as_CountedLoop()->do_unroll_only()) return false;
 
+  if (_head->is_CountedLoop() && _head->as_CountedLoop()->trip_count() == 1) {
+    return false;
+  }
+
   while( test != _head ) {      // Scan till run off top of loop
     if( test->is_If() ) {       // Test?
       Node *ctrl = phase->get_ctrl(test->in(1));
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/PeelingZeroTripCount.java	Thu Dec 13 17:57:11 2018 +0100
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8215044
+ * @summary C2 crash in loopTransform.cpp with assert(cl->trip_count() > 0) failed: peeling a fully unrolled loop
+ *
+ * @run main/othervm -XX:CompileOnly=PeelingZeroTripCount.test PeelingZeroTripCount
+ *
+ */
+
+public class PeelingZeroTripCount {
+
+    public static void main(String[] args) {
+        PeelingZeroTripCount issue = new PeelingZeroTripCount();
+        for (int i = 0; i < 10000; i++) {
+            issue.test(new int[999]);
+        }
+    }
+
+    public void test(int[] iaarg) {
+        int[] iarr = new int[777];
+        for (int i = 4; i > 0; i--) {
+            for (int j = 0; j <= i - 1; j++) {
+                int istep = 2 * j - i + 1;
+                int iadj = 0;
+                if (istep < 0) {
+                    iadj = iarr[0-istep] + iaarg[i-1];
+                } else {
+                    iadj = iarr[istep] + iaarg[i-1];
+                }
+            }
+        }
+    }
+}