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/*
* Copyright (c) 2018, Red Hat, Inc. 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 8193130 8203915
* @summary Bad graph when unrolled loop bounds conflicts with range checks
* @requires vm.flavor == "server"
*
* @run main/othervm IterationSplitPredicateInconsistency
* @run main/othervm -XX:-UseLoopPredicate IterationSplitPredicateInconsistency
* @run main/othervm -XX:LoopStripMiningIter=0 IterationSplitPredicateInconsistency
*
*/
public class IterationSplitPredicateInconsistency {
static volatile int barrier;
// Pollute profile so loop appears to run for a large number of iterations
static boolean test1_helper(int start, int stop, double[] array1, double[] array2, int exit) {
for (int i = start; i < stop; i++) {
array1[i] = array2[i];
if (i == exit) {
return true;
}
barrier = 0x42;
}
return false;
}
static double[] test1(int start, double[] array2, int exit) {
double[] array1 = new double[10];
// Predication moves range checks out of loop and
// pre/main/post loops are created. The main loop is unrolled
// several times to the point where it's never executed but
// compiler can't tell from the loop bounds alone. The lower
// bound of the loop is negative and would cause range checks
// (that were removed from the loop body) to fail.
if (test1_helper(start, 5, array1, array2, exit)) {
return null;
}
return array1;
}
// Same as above with other combinations of increasing/decreasing
// loops, positive/negative stride
static boolean test2_helper(int start, int stop, double[] array1, double[] array2, int exit) {
for (int i = start-1; i >= stop; i--) {
array1[i] = array2[i];
if (i == exit) {
return true;
}
barrier = 0x42;
}
return false;
}
static double[] test2(int start, double[] array2, int exit) {
double[] array1 = new double[10];
if (test2_helper(start, 0, array1, array2, exit)) {
return null;
}
return array1;
}
static boolean test3_helper(int start, int stop, double[] array1, double[] array2, int exit) {
for (int i = start; i < stop; i++) {
array1[stop-i-1] = array2[stop-i-1];
if (i == exit) {
return true;
}
barrier = 0x42;
}
return false;
}
static double[] test3(int start, double[] array2, int exit) {
double[] array1 = new double[5];
if (test3_helper(start, 5, array1, array2, exit)) {
return null;
}
return array1;
}
static boolean test4_helper(int start, int stop, int from, double[] array1, double[] array2, int exit) {
for (int i = start-1; i >= stop; i--) {
array1[from-i-1] = array2[from-i-1];
if (i == exit) {
return true;
}
barrier = 0x42;
}
return false;
}
static double[] test4(int start, double[] array2, int exit) {
double[] array1 = new double[5];
if (test4_helper(start, 0, 5, array1, array2, exit)) {
return null;
}
return array1;
}
public static void main(String[] args) {
double[] array2 = new double[10];
double[] array3 = new double[1000];
for (int i = 0; i < 20_000; i++) {
test1_helper(0, 1000, array3, array3, 998);
test1(0, array2, 999);
test1(0, array2, 4);
test2_helper(1000, 0, array3, array3, 1);
test2(5, array2, 999);
test2(5, array2, 1);
test3_helper(0, 1000, array3, array3, 998);
test3(0, array2, 999);
test3(0, array2, 4);
test4_helper(1000, 0, 1000, array3, array3, 1);
test4(5, array2, 999);
test4(5, array2, 1);
}
}
}
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