undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/hotspot/jtreg/compiler/loopopts/TestBaseCountedEndLoopUnswitchCandidate.java

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+/*
+ * Copyright (c) 2024, 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 8325746
+ * @summary Test Loop Unswitching with BaseCountedLoopEnd nodes as unswitch candidate.
+ * @requires vm.compiler2.enabled
+ * @run main/othervm -XX:CompileCommand=compileonly,compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate::test*
+ *                   -Xcomp -XX:LoopMaxUnroll=0 -XX:-UseLoopPredicate -XX:-RangeCheckElimination
+ *                   compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate
+ * @run main compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate
+ */
+
+package compiler.loopopts;
+
+public class TestBaseCountedEndLoopUnswitchCandidate {
+    static int iFld;
+    static long lFld;
+    static A a = new A();
+    static boolean flag;
+
+    public static void main(String[] k) {
+        for (int i = 0; i < 10000; i++) {
+            testLongCountedLoopEnd();
+            testCountedLoopEnd();
+        }
+    }
+
+    public static void testLongCountedLoopEnd() {
+        long limit = lFld;
+        for (int i = 0; i < 100; i++) {
+
+            // After peeling & IGNV:
+            //      LongCountedEndLoop
+            //           /      \
+            //         True    False
+            //        / \       /
+            //  Store    Region
+            //
+            // LongCountedEndLoop has both paths inside loop and is therefore selected as unswitch candidate If in
+            // Loop Unswitching.
+
+            // Use stride > Integer.MAX_VALUE such that LongCountedLoopNode is not split further into loop nests.
+            for (long j = 0; j < limit; j+=2147483648L) {
+                a.i += 34; // NullCheck with trap on false path -> reason to peel
+                if (j > 0) { // After peeling: j > 0 always true -> loop folded away
+                    break;
+                }
+            }
+        }
+    }
+
+    public static void testCountedLoopEnd() {
+        int limit = iFld;
+        for (int i = 0; i < 100; i++) {
+
+            // After peeling & IGNV:
+            //        CountedLoopEnd
+            //           /      \
+            //         True    False
+            //        / \       /
+            //  Store    Region
+            //
+            // CountedEndLoop has both paths inside loop and is therefore selected as unswitch candidate If in
+            // Loop Unswitching.
+
+            for (int j = 0; j < limit; j++) {
+                a.i += 34; // NullCheck with trap on false path -> reason to peel
+                if (j > 0) { // After peeling: j > 0 always true -> loop folded away
+                    break;
+                }
+            }
+        }
+    }
+}
+
+class A {
+    int i;
+}