| /* |
| * Copyright (c) 2025, 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 |
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| */ |
| |
| /* |
| * @test |
| * @bug 8335747 |
| * @summary Integer overflow in LoopLimit::Value during PhaseIdealLoop::split_thru_phi |
| * @run main/othervm -Xbatch -XX:CompileCommand=compileonly,TestLoopLimitOverflowDuringSplitThruPhi::test |
| * compiler.loopopts.TestLoopLimitOverflowDuringSplitThruPhi |
| * @run driver compiler.loopopts.TestLoopLimitOverflowDuringSplitThruPhi |
| */ |
| |
| package compiler.loopopts; |
| |
| public class TestLoopLimitOverflowDuringSplitThruPhi { |
| public static void main(String[] args) { |
| int[] a = new int[1005]; |
| for (int i = 0; i < 20_000; i++) { |
| test(i % 2 == 0, a); |
| } |
| } |
| |
| static void test(boolean flag, int[] a) { |
| int x = flag ? 1000 : 2147483647; |
| // Creates a Phi(1000, 2147483647) |
| |
| // We do loop-predication, and add a |
| // LoopLimitNode(init=0, limit=x, stride=4) |
| // |
| // Later, we find try to PhaseIdealLoop::split_thru_phi |
| // the LoopLimitNode, through the Phi(1000, 2147483647). |
| // |
| // This creates a temporary |
| // LoopLimitNode(init=0, limit=2147483647, stride=4) |
| // |
| // And then we get this: |
| // init_con 0 |
| // limit_con 2147483647 |
| // stride_con 4 |
| // trip_count 536870912 |
| // final_int -2147483648 |
| // final_con 2147483648 |
| // |
| for (int i = 0; i < x; i+=4 /* works for at least 2..64 */) { |
| // Break before going out of bounds |
| // but with quadratic check to not affect limit. |
| if (i * i > 1000_000) { return; } |
| a[i] = 34; |
| } |
| } |
| } |
