74 lines
2.3 KiB
Java
74 lines
2.3 KiB
Java
/*
|
|
* Copyright (c) 2022, 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 8288445
|
|
* @summary Test shift by 0
|
|
* @run main/othervm -Xbatch -XX:-TieredCompilation
|
|
* compiler.codegen.ShiftByZero
|
|
*/
|
|
|
|
package compiler.codegen;
|
|
|
|
public class ShiftByZero {
|
|
|
|
public static final int N = 64;
|
|
|
|
public static int[] i32 = new int[N];
|
|
|
|
public static void bMeth() {
|
|
int shift = i32[0];
|
|
// This loop is to confuse the optimizer, so that "shift" is
|
|
// optimized to 0 only after loop vectorization.
|
|
for (int i8 = 279; i8 > 1; --i8) {
|
|
shift <<= 6;
|
|
}
|
|
// low 6 bits of shift are 0, so shift can be
|
|
// simplified to constant 0
|
|
{
|
|
for (int i = 0; i < N; ++i) {
|
|
i32[i] += i32[i] >>= shift;
|
|
}
|
|
for (int i = 0; i < N; ++i) {
|
|
i32[i] += i32[i] >>>= shift;
|
|
}
|
|
for (int i = 0; i < N; ++i) {
|
|
i32[i] >>>= shift;
|
|
}
|
|
for (int i = 0; i < N; ++i) {
|
|
i32[i] >>= shift;
|
|
}
|
|
for (int i = 0; i < N; ++i) {
|
|
i32[i] <<= shift;
|
|
}
|
|
}
|
|
}
|
|
|
|
public static void main(String[] strArr) {
|
|
for (int i = 0; i < 20_000; i++) {
|
|
bMeth();
|
|
}
|
|
}
|
|
}
|