8241726: Re-enable gtest for BitMap::count_one_bits()

Reviewed-by: mdoerr, clanger

test/hotspot/gtest/utilities/test_bitMap_popcnt.cpp

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, SAP and/or its affiliates.
+ *
+ * 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.
+ */
+
+#include "precompiled.hpp"
+#include "memory/allocation.hpp"
+#include "runtime/os.hpp"
+#include "utilities/bitMap.inline.hpp"
+#include "utilities/ostream.hpp"
+#include "unittest.hpp"
+
+// A simple stupid bitmap to mimic BitMap operations.
+class SimpleFakeBitmap {
+
+  const int _size;
+  char* _buffer;
+
+public:
+
+  SimpleFakeBitmap(int size) : _size(size), _buffer(NEW_C_HEAP_ARRAY(char, size, mtInternal)) {
+    clear();
+  }
+
+  ~SimpleFakeBitmap() {
+    FREE_C_HEAP_ARRAY(char, _buffer);
+  }
+
+  // Set or clear the specified bit.
+  void set_range(int beg, int end) { ::memset(_buffer + beg, 'X', end - beg); }
+  void clear_range(int beg, int end) { ::memset(_buffer + beg, ' ', end - beg); }
+  void clear() { clear_range(0, _size); }
+
+  bool at(int idx) const { return _buffer[idx] == 'X'; }
+
+  unsigned popcnt(int beg, int end) const {
+    int sum = 0;
+    for (int i = beg; i < end; i ++) {
+      if (at(i)) {
+        sum ++;
+      }
+    }
+    return sum;
+  }
+
+  unsigned popcnt() const { return popcnt(0, _size); }
+
+};
+
+#define ASSERT_POPCNT_ALL(bm, expected) \
+  ASSERT_EQ(bm.count_one_bits(), (BitMap::idx_t)(expected));
+
+#define ASSERT_POPCNT_RANGE(bm, beg, end, expected) \
+  ASSERT_EQ(bm.count_one_bits(beg, end), (BitMap::idx_t)(expected));
+
+#define ASSERT_POPCNT_ALL_CMP(bm, fake_bm) \
+  ASSERT_EQ(bm.count_one_bits(), fake_bm.popcnt());
+
+#define ASSERT_POPCNT_RANGE_CMP(bm, beg, end, fake_bm) \
+  ASSERT_EQ(bm.count_one_bits(beg, end), fake_bm.popcnt(beg, end));
+
+static void set_or_clear_random_range(BitMap& bm, SimpleFakeBitmap& fbm, int beg, int end) {
+  int range = end - beg;
+  if (range > 0) {
+    int from = os::random() % range;
+    int to = os::random() % range;
+    if (from > to) {
+      int s = from;
+      from = to;
+      to = s;
+    }
+    from += beg;
+    to += beg;
+    if ((os::random() % 10) > 5) {
+      bm.set_range(from, to);
+      fbm.set_range(from, to);
+    } else {
+      bm.clear_range(from, to);
+      fbm.clear_range(from, to);
+    }
+  }
+}
+
+static void test_bitmap_popcnt(int bitsize) {
+  CHeapBitMap bm(bitsize);
+  SimpleFakeBitmap fbm(bitsize);
+
+  ASSERT_POPCNT_ALL(bm, 0);
+  ASSERT_POPCNT_RANGE(bm, 0, 0, 0);
+  ASSERT_POPCNT_RANGE(bm, 0, bitsize, 0);
+
+  const int stepsize = bitsize > 64 ? 5 : 1;
+
+  for (int beg = 0; beg < bitsize; beg += stepsize) {
+    for (int end = beg; end < bitsize; end += stepsize) {
+
+      bm.clear();
+      bm.set_range(beg, end);
+
+      fbm.clear();
+      fbm.set_range(beg, end);
+
+      ASSERT_POPCNT_ALL_CMP(bm, fbm);
+
+      for (int beg_query_range = 0; beg_query_range < bitsize; beg_query_range += stepsize) {
+        for (int end_query_range = beg_query_range; end_query_range < bitsize; end_query_range += stepsize) {
+          ASSERT_POPCNT_RANGE_CMP(bm, beg_query_range, end_query_range, fbm);
+
+          // Clear some random ranges and retest
+          for (int n = 0; n < 3; n ++) {
+            set_or_clear_random_range(bm, fbm, beg, end);
+            ASSERT_POPCNT_RANGE_CMP(bm, beg_query_range, end_query_range, fbm);
+          }
+
+        }
+      }
+    }
+  }
+
+}
+
+TEST_VM(BitMap, popcnt_1)   { test_bitmap_popcnt(1); }
+TEST_VM(BitMap, popcnt_8)   { test_bitmap_popcnt(8); }
+TEST_VM(BitMap, popcnt_15)  { test_bitmap_popcnt(15); }
+TEST_VM(BitMap, popcnt_19)  { test_bitmap_popcnt(17); }
+TEST_VM(BitMap, popcnt_63)  { test_bitmap_popcnt(63); }
+TEST_VM(BitMap, popcnt_300) { test_bitmap_popcnt(300); }
+
+TEST_VM(BitMap, popcnt_large) {
+
+  CHeapBitMap bm(64 * K);
+
+  ASSERT_POPCNT_ALL(bm, 0);
+  ASSERT_POPCNT_RANGE(bm, 0, 64 * K, 0);
+  ASSERT_POPCNT_RANGE(bm, 47, 199, 0);
+
+  bm.set_bit(100);
+
+  ASSERT_POPCNT_ALL(bm, 1);
+  ASSERT_POPCNT_RANGE(bm, 0, 64 * K, 1);
+  ASSERT_POPCNT_RANGE(bm, 47, 199, 1);
+  ASSERT_POPCNT_RANGE(bm, 199, 299, 0 );
+
+  bm.set_range(0, 64 * K);
+
+  ASSERT_POPCNT_ALL(bm, 64 * K);
+  ASSERT_POPCNT_RANGE(bm, 0, 64 * K, 64 * K);
+  ASSERT_POPCNT_RANGE(bm, 47, 199, 152);
+  ASSERT_POPCNT_RANGE(bm, 199, 299, 100);
+
+}
+