diff test/compiler/rangechecks/TestRangeCheckSmearingLoopOpts.java @ 20701:b6585ac86988

8048170: Test closed/java/text/Normalizer/ConformanceTest.java failed Summary: PhaseIdealLoop::split_if_with_blocks_post() shoulnd't reorder range checks adjusted by range check smearing Reviewed-by: kvn, jrose
author roland
date Thu, 04 Dec 2014 14:34:11 +0100
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/rangechecks/TestRangeCheckSmearingLoopOpts.java	Thu Dec 04 14:34:11 2014 +0100
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+/*
+ * 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) {}
+    }
+}