russell@unturf.com
0a580b313d
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.
64 lines
2.3 KiB
Java
64 lines
2.3 KiB
Java
/*
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* Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package compiler.c2.gvn;
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/*
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* @test
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* @bug 8374798
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* @summary RShift(LShift(x, C), C) Identity missed when shift counts are different
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* constant nodes for the same effective count (e.g. -1 vs 31) due to
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* mask_and_replace_shift_amount normalizing them at different times.
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*
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* @run main ${test.main.class}
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* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions
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* -XX:+StressIGVN -XX:+StressCCP -XX:VerifyIterativeGVN=1000 -Xbatch -XX:-TieredCompilation
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* -XX:CompileCommand=compileonly,${test.main.class}::test* ${test.main.class}
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*/
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public class MissedRShiftLShiftIdentity {
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public static int iFld = 0;
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public static void test() {
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int[] iArr = new int[10];
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int i2 = -1, i3 = 0;
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for (int i11 : iArr) {
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iFld = i11;
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for (int i1 = 0; i1 < 10; i1++) {
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iFld <<= i3;
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iFld >>= i2; // RShift
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i3 = i2;
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}
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int i16 = 0;
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do {
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for (int f3 = 1; f3 < 1; f3 += 3) {
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i2 = -1;
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}
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} while (++i16 < 5);
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}
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}
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public static void main(String[] args) {
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test();
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}
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}
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