6863155: Server compiler generates incorrect code (x86, long, bitshift, bitmask)
Summary: Code compiled with server compiler generates an incorrect result.
Reviewed-by: cfang, never, kvn
--- a/hotspot/src/share/vm/opto/mulnode.cpp Mon Jul 27 06:15:29 2009 -0700
+++ b/hotspot/src/share/vm/opto/mulnode.cpp Tue Jul 28 09:02:30 2009 +0200
@@ -608,16 +608,14 @@
}
// Are we masking a long that was converted from an int with a mask
- // that fits in 32-bits? Commute them and use an AndINode.
- if (op == Op_ConvI2L && (mask & CONST64(0xFFFFFFFF00000000)) == 0) {
- // If we are doing an UI2L conversion (i.e. the mask is
- // 0x00000000FFFFFFFF) we cannot convert the AndL to an AndI
- // because the AndI would be optimized away later in Identity.
- if (mask != CONST64(0x00000000FFFFFFFF)) {
- Node* andi = new (phase->C, 3) AndINode(in1->in(1), phase->intcon(mask));
- andi = phase->transform(andi);
- return new (phase->C, 2) ConvI2LNode(andi);
- }
+ // that fits in 32-bits? Commute them and use an AndINode. Don't
+ // convert masks which would cause a sign extension of the integer
+ // value. This check includes UI2L masks (0x00000000FFFFFFFF) which
+ // would be optimized away later in Identity.
+ if (op == Op_ConvI2L && (mask & CONST64(0xFFFFFFFF80000000)) == 0) {
+ Node* andi = new (phase->C, 3) AndINode(in1->in(1), phase->intcon(mask));
+ andi = phase->transform(andi);
+ return new (phase->C, 2) ConvI2LNode(andi);
}
// Masking off sign bits? Dont make them!
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/6863155/Test6863155.java Tue Jul 28 09:02:30 2009 +0200
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2009 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/**
+ * @test
+ * @bug 6863155
+ * @summary Server compiler generates incorrect code (x86, long, bitshift, bitmask)
+ *
+ * @run main/othervm -Xcomp -XX:CompileOnly=Test6863155.test Test6863155
+ */
+
+public class Test6863155 {
+ private static long test(byte b) {
+ return b << 24 & 0xff000000L;
+ }
+
+ public static void main(String... args) {
+ long result = test((byte) 0xc2);
+ long expected = 0x00000000c2000000L;
+ if (result != expected)
+ throw new InternalError(Long.toHexString(result) + " != " + Long.toHexString(expected));
+ }
+}