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
--- 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 = 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");
+ 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);
}
- break;
+ 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_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);
+ }
+ }
+}