changeset 56882:586415e8abcb

8229694: JVM crash in SWPointer during C2 OSR compilation Summary: Handle the case where there is only 1 pack and no operations left when calling SuperWord::find_align_to_ref() to find the best alignment again. Reviewed-by: kvn, vlivanov, thartmann
author chagedorn
date Mon, 11 Nov 2019 10:41:03 +0100
parents d595f1faace2
children 01d47d511f5f
files src/hotspot/share/opto/superword.cpp test/hotspot/jtreg/compiler/loopopts/superword/AlignmentOnePack.java
diffstat 2 files changed, 81 insertions(+), 15 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/opto/superword.cpp	Sat Nov 09 10:27:53 2019 -0800
+++ b/src/hotspot/share/opto/superword.cpp	Mon Nov 11 10:41:03 2019 +0100
@@ -699,24 +699,34 @@
         // Put memory ops from remaining packs back on memops list for
         // the best alignment search.
         uint orig_msize = memops.size();
-        for (int i = 0; i < _packset.length(); i++) {
-          Node_List* p = _packset.at(i);
+        if (_packset.length() == 1 && orig_msize == 0) {
+          // If there are no remaining memory ops and only 1 pack we have only one choice
+          // for the alignment
+          Node_List* p = _packset.at(0);
+          assert(p->size() > 0, "sanity");
           MemNode* s = p->at(0)->as_Mem();
           assert(!same_velt_type(s, mem_ref), "sanity");
-          memops.push(s);
+          best_align_to_mem_ref = s;
+        } else {
+          for (int i = 0; i < _packset.length(); i++) {
+            Node_List* p = _packset.at(i);
+            MemNode* s = p->at(0)->as_Mem();
+            assert(!same_velt_type(s, mem_ref), "sanity");
+            memops.push(s);
+          }
+          best_align_to_mem_ref = find_align_to_ref(memops);
+          if (best_align_to_mem_ref == NULL) {
+            if (TraceSuperWord) {
+              tty->print_cr("SuperWord::find_adjacent_refs(): best_align_to_mem_ref == NULL");
+            }
+            break;
+          }
+          best_iv_adjustment = get_iv_adjustment(best_align_to_mem_ref);
+          NOT_PRODUCT(find_adjacent_refs_trace_1(best_align_to_mem_ref, best_iv_adjustment);)
+          // Restore list.
+          while (memops.size() > orig_msize)
+            (void)memops.pop();
         }
-        best_align_to_mem_ref = find_align_to_ref(memops);
-        if (best_align_to_mem_ref == NULL) {
-          if (TraceSuperWord) {
-            tty->print_cr("SuperWord::find_adjacent_refs(): best_align_to_mem_ref == NULL");
-          }
-          break;
-        }
-        best_iv_adjustment = get_iv_adjustment(best_align_to_mem_ref);
-        NOT_PRODUCT(find_adjacent_refs_trace_1(best_align_to_mem_ref, best_iv_adjustment);)
-        // Restore list.
-        while (memops.size() > orig_msize)
-          (void)memops.pop();
       }
     } // unaligned memory accesses
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/superword/AlignmentOnePack.java	Mon Nov 11 10:41:03 2019 +0100
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. 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 8229694
+ * @summary Tests the case where there is only 1 pack and no operations left when calling SuperWord::find_align_to_ref() to find the best alignment again.
+ *
+ * @run main/othervm -Xbatch -XX:CompileCommand=compileonly,compiler.loopopts.superword.AlignmentOnePack::test
+ *      compiler.loopopts.superword.AlignmentOnePack
+ */
+
+package compiler.loopopts.superword;
+
+public class AlignmentOnePack {
+    static int iFld;
+
+    public static void test(int[] intArr, short[] shortArr) {
+        for (int j = 8; j < intArr.length;j++) {
+            shortArr[10] = 10;
+            shortArr[j] = 30;
+            intArr[7] = 260;
+            intArr[j-1] = 400;
+            iFld = intArr[j];
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        int[] a = new int[16];
+        short[] c = new short[16];
+
+        for (int i = 0; i < 10000; i++) {
+            test(a, c);
+        }
+    }
+}