/* * Copyright (c) 2026, 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. */ package compiler.c2.gvn; /* * @test * @bug 8374798 * @summary RShift(LShift(x, C), C) Identity missed when shift counts are different * constant nodes for the same effective count (e.g. -1 vs 31) due to * mask_and_replace_shift_amount normalizing them at different times. * * @run main ${test.main.class} * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions * -XX:+StressIGVN -XX:+StressCCP -XX:VerifyIterativeGVN=1000 -Xbatch -XX:-TieredCompilation * -XX:CompileCommand=compileonly,${test.main.class}::test* ${test.main.class} */ public class MissedRShiftLShiftIdentity { public static int iFld = 0; public static void test() { int[] iArr = new int[10]; int i2 = -1, i3 = 0; for (int i11 : iArr) { iFld = i11; for (int i1 = 0; i1 < 10; i1++) { iFld <<= i3; iFld >>= i2; // RShift i3 = i2; } int i16 = 0; do { for (int f3 = 1; f3 < 1; f3 += 3) { i2 = -1; } } while (++i16 < 5); } } public static void main(String[] args) { test(); } }