| /* |
| * Copyright (c) 2014, 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 8048170 |
| * @summary Following range check smearing, range check cannot be replaced by dominating identical test. |
| * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement TestRangeCheckSmearingLoopOpts |
| * |
| */ |
| public class TestRangeCheckSmearingLoopOpts { |
| |
| static int dummy; |
| |
| static int m1(int[] array, int i) { |
| for (;;) { |
| for (;;) { |
| if (array[i] < 0) { // range check (i+0) dominates equivalent check below |
| break; |
| } |
| i++; |
| } |
| |
| // A control flow that stops IfNode::up_one_dom() |
| if ((i % 2)== 0) { |
| if ((array[i] % 2) == 0) { |
| dummy = i; |
| } |
| } |
| |
| // IfNode::Ideal will rewrite some range checks if Compile::allow_range_check_smearing |
| if (array[i-1] == 9) { // range check (i-1) unchanged |
| int res = array[i-3]; // range check (i-3) unchanged |
| res += array[i]; // range check (i+0) unchanged |
| res += array[i-2]; // removed redundant range check |
| // the previous access might be hoisted by |
| // PhaseIdealLoop::split_if_with_blocks_post because |
| // it appears to have the same guard, but it also |
| // depends on the previous guards |
| return res; |
| } |
| i++; |
| } |
| } |
| |
| static public void main(String[] args) { |
| int[] array = { 0, 1, 2, -3, 4, 5, -2, 7, 8, 9, -1 }; |
| for (int i = 0; i < 20000; i++) { |
| m1(array, 0); |
| } |
| array[0] = -1; |
| try { |
| m1(array, 0); |
| } catch(ArrayIndexOutOfBoundsException aioobe) {} |
| } |
| } |
