--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/test/hotspot/gtest/gc/z/test_zPhysicalMemory.cpp	2018-06-08 19:47:02.110539162 +0200
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * ORACLE PROPRIETARY/CONFIDENTIAL.  Use is subject to license terms.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zPhysicalMemory.inline.hpp"
+#include "utilities/debug.hpp"
+#include "unittest.hpp"
+
+#if defined(AMD64)
+
+TEST(ZPhysicalMemorySegmentTest, split) {
+  const size_t SegmentSize = 2 * M;
+
+  ZPhysicalMemorySegment seg(0, 10 * SegmentSize);
+
+  ZPhysicalMemorySegment seg_split0 = seg.split(0 * SegmentSize);
+  EXPECT_EQ(seg_split0.size(),  0 * SegmentSize);
+  EXPECT_EQ(       seg.size(), 10 * SegmentSize);
+
+  ZPhysicalMemorySegment seg_split1 = seg.split(5 * SegmentSize);
+  EXPECT_EQ(seg_split1.size(),  5 * SegmentSize);
+  EXPECT_EQ(       seg.size(),  5 * SegmentSize);
+
+  ZPhysicalMemorySegment seg_split2 = seg.split(5 * SegmentSize);
+  EXPECT_EQ(seg_split2.size(),  5 * SegmentSize);
+  EXPECT_EQ(       seg.size(),  0 * SegmentSize);
+
+  ZPhysicalMemorySegment seg_split3 = seg.split(0 * SegmentSize);
+  EXPECT_EQ(seg_split3.size(),  0 * SegmentSize);
+  EXPECT_EQ(       seg.size(),  0 * SegmentSize);
+}
+
+TEST(ZPhysicalMemoryTest, split) {
+  const size_t SegmentSize = 2 * M;
+
+  ZPhysicalMemoryManager pmem_manager(10 * SegmentSize, SegmentSize);
+
+  ZPhysicalMemory pmem = pmem_manager.alloc(8 * SegmentSize);
+  EXPECT_EQ(pmem.nsegments(), 1u) << "wrong number of segments";
+
+  ZPhysicalMemory split0_pmem = pmem.split(SegmentSize);
+  EXPECT_EQ(split0_pmem.nsegments(), 1u);
+  EXPECT_EQ(       pmem.nsegments(), 1u);
+  EXPECT_EQ(split0_pmem.size(), 1 * SegmentSize);
+  EXPECT_EQ(       pmem.size(), 7 * SegmentSize);
+
+  ZPhysicalMemory split1_pmem = pmem.split(2 * SegmentSize);
+  EXPECT_EQ(split1_pmem.nsegments(), 1u);
+  EXPECT_EQ(       pmem.nsegments(), 1u);
+  EXPECT_EQ(split1_pmem.size(), 2 * SegmentSize);
+  EXPECT_EQ(       pmem.size(), 5 * SegmentSize);
+
+  ZPhysicalMemory split2_pmem = pmem.split(5 * SegmentSize);
+  EXPECT_EQ(split2_pmem.nsegments(), 1u);
+  EXPECT_EQ(       pmem.nsegments(), 1u);
+  EXPECT_EQ(split2_pmem.size(), 5 * SegmentSize);
+  EXPECT_EQ(       pmem.size(), 0 * SegmentSize);
+}
+
+#endif