diff --git a/src/hotspot/share/opto/loopTransform.cpp b/src/hotspot/share/opto/loopTransform.cpp index 787cf99b20f..e35657cd16a 100644 --- a/src/hotspot/share/opto/loopTransform.cpp +++ b/src/hotspot/share/opto/loopTransform.cpp @@ -2332,6 +2332,8 @@ void PhaseIdealLoop::do_unroll(IdealLoopTree *loop, Node_List &old_new, bool adj // can edit it's inputs directly. Hammer in the new limit for the // minimum-trip guard. assert(opaq->outcnt() == 1, ""); + // Notify limit -> opaq -> CmpI, it may constant fold. + _igvn.add_users_to_worklist(opaq->in(1)); _igvn.replace_input_of(opaq, 1, new_limit); } diff --git a/test/hotspot/jtreg/compiler/loopopts/TestNotifyOpaqueZeroTripGuardToCmpI.java b/test/hotspot/jtreg/compiler/loopopts/TestNotifyOpaqueZeroTripGuardToCmpI.java new file mode 100644 index 00000000000..c00dea51e32 --- /dev/null +++ b/test/hotspot/jtreg/compiler/loopopts/TestNotifyOpaqueZeroTripGuardToCmpI.java @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2023, 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 8316361 + * @summary Test that if input to OpaqueZeroTripGuard changes, we notify down to CmpI. + * @run main/othervm -Xcomp -XX:+IgnoreUnrecognizedVMOptions -XX:VerifyIterativeGVN=10 + * -XX:CompileCommand=compileonly,compiler.loopopts.TestNotifyOpaqueZeroTripGuardToCmpI::test + * compiler.loopopts.TestNotifyOpaqueZeroTripGuardToCmpI + */ +package compiler.loopopts; + +public class TestNotifyOpaqueZeroTripGuardToCmpI { + static int x, y; + + public static void main(String[] strArr) { + test(); + } + + static void test() { + for (int i = 6; i < 43; i++) { + for (int j = i; j < 11; j++) { + x = y; + } + } + } +}