diff --git a/src/hotspot/share/opto/movenode.cpp b/src/hotspot/share/opto/movenode.cpp index 8d9cc80e69e..58feb3ec9ce 100644 --- a/src/hotspot/share/opto/movenode.cpp +++ b/src/hotspot/share/opto/movenode.cpp @@ -169,6 +169,13 @@ const Type* CMoveNode::Value(PhaseGVN* phase) const { if (phase->type(in(IfTrue)) == Type::TOP || phase->type(in(IfFalse)) == Type::TOP) { return Type::TOP; } + if (phase->type(in(Condition)) == TypeInt::ZERO) { + return phase->type(in(IfFalse))->filter(_type); // Always pick left (false) input + } + if (phase->type(in(Condition)) == TypeInt::ONE) { + return phase->type(in(IfTrue))->filter(_type); // Always pick right (true) input + } + const Type* t = phase->type(in(IfFalse))->meet_speculative(phase->type(in(IfTrue))); return t->filter(_type); } diff --git a/test/hotspot/jtreg/compiler/c2/irTests/TestCMoveCCP.java b/test/hotspot/jtreg/compiler/c2/irTests/TestCMoveCCP.java new file mode 100644 index 00000000000..475e8565b28 --- /dev/null +++ b/test/hotspot/jtreg/compiler/c2/irTests/TestCMoveCCP.java @@ -0,0 +1,71 @@ +/* + * Copyright (c) 2024, Red Hat 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. + */ + +package compiler.c2.irTests; + +import compiler.lib.ir_framework.*; + +/* + * @test + * @bug 8330163 + * @summary C2: improve CMoveNode::Value() when condition is always true or false + * @library /test/lib / + * @run driver compiler.c2.irTests.TestCMoveCCP + */ + + +public class TestCMoveCCP { + private static volatile int volatileField; + + public static void main(String[] args) { + TestFramework.run(); + } + + @Test + @IR(failOn = { IRNode.COUNTED_LOOP, IRNode.LOOP }) + private static void test1() { + int i = -1; + testHelper1(i); + } + + @ForceInline + private static void testHelper1(int i) { + do { + if (i != 1) { + if (i < 0) { // Converted to CMoveI + i = 50; + } + volatileField = 42; + } + i *= 2; + // i = 100 on first iteration when called from test1 + } while (i != 100); + } + + @Run(test = "test1") + @Warmup(10000) + private static void testRunner1() { + test1(); + testHelper1(1); + } +}