7100757: The BitSet.nextSetBit() produces incorrect result in 32bit VM on Sparc
authorkvn
Fri, 14 Oct 2011 10:07:28 -0700
changeset 10736 1a11ec86574e
parent 10735 67a139f9f954
child 10737 6418bdce015b
7100757: The BitSet.nextSetBit() produces incorrect result in 32bit VM on Sparc Summary: Instruction countTrailingZerosL() should use iRegIsafe dst register since it is used in long arithmetic. Reviewed-by: never, twisti
hotspot/src/cpu/sparc/vm/sparc.ad
hotspot/test/compiler/7100757/Test7100757.java
--- a/hotspot/src/cpu/sparc/vm/sparc.ad	Thu Oct 13 14:08:15 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/sparc.ad	Fri Oct 14 10:07:28 2011 -0700
@@ -10476,7 +10476,7 @@
   ins_pipe(ialu_reg);
 %}
 
-instruct countTrailingZerosL(iRegI dst, iRegL src, flagsReg cr) %{
+instruct countTrailingZerosL(iRegIsafe dst, iRegL src, flagsReg cr) %{
   predicate(UsePopCountInstruction);  // See Matcher::match_rule_supported
   match(Set dst (CountTrailingZerosL src));
   effect(TEMP dst, KILL cr);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/7100757/Test7100757.java	Fri Oct 14 10:07:28 2011 -0700
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2011, 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 7100757
+ * @summary The BitSet.nextSetBit() produces incorrect result in 32bit VM on Sparc
+ *
+ * @run main/timeout=300 Test7100757
+ */
+
+import java.util.*;
+
+public class Test7100757 {
+
+  public static final int NBITS = 256;
+
+  public static void main(String[] args) {
+
+    BitSet bs = new BitSet(NBITS);
+    Random rnd = new Random();
+    long[] ra = new long[(NBITS+63)/64];
+
+    for(int l=0; l < 5000000; l++) {
+
+      for(int r = 0; r < ra.length; r++) {
+        ra[r] = rnd.nextLong();
+      }
+      test(ra, bs);
+    }
+  }
+
+  static void test(long[] ra, BitSet bs) {
+      bs.clear();
+      int bits_set = 0;
+      for(int i = 0, t = 0, b = 0; i < NBITS; i++) {
+        long bit = 1L << b++;
+        if((ra[t]&bit) != 0) {
+          bs.set(i);
+          bits_set++;
+        }
+        if(b == 64) {
+          t++;
+          b = 0;
+        }
+      }
+      // Test Long.bitCount()
+      int check_bits = bs.cardinality();
+      if (check_bits != bits_set) {
+        String bs_str = bs.toString();
+        System.err.printf("cardinality bits: %d != %d  bs: %s\n", check_bits, bits_set, bs_str);
+        System.exit(97);
+      }
+      // Test Long.numberOfTrailingZeros()
+      check_bits = 0;
+      for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
+        check_bits++;
+      }
+      if (check_bits != bits_set) {
+        String bs_str = bs.toString();
+        System.err.printf("nextSetBit bits: %d != %d  bs: %s\n", check_bits, bits_set, bs_str);
+        System.exit(97);
+      }
+      // Test Long.numberOfLeadingZeros()
+      for(int i = bs.length(); i > 0; i = bs.length()) {
+        bs.clear(i-1);
+      }
+      // Test Long.bitCount()
+      check_bits = bs.cardinality();
+      if (check_bits != 0) {
+        String bs_str = bs.toString();
+        System.err.printf("after clear bits: %d != 0  bs: %s\n", check_bits, bs_str);
+        System.exit(97);
+      }
+  }
+
+};