changeset 3597:572bbef24585

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
author twisti
date Tue, 28 Jul 2009 09:02:30 +0200
parents baa6856ba14e
children bfff77083467
files hotspot/src/share/vm/opto/mulnode.cpp hotspot/test/compiler/6863155/Test6863155.java
diffstat 2 files changed, 51 insertions(+), 10 deletions(-) [+]
line wrap: on
line diff
--- 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));
+    }
+}