Mercurial > jdk8-mips64-public > hotspot / changeset

     1.1 --- a/src/share/vm/opto/memnode.cpp	Wed Jun 07 13:59:35 2017 -0400
     1.2 +++ b/src/share/vm/opto/memnode.cpp	Tue Jul 25 10:10:41 2017 -0400
     1.3 @@ -1,5 +1,5 @@
     1.4  /*
     1.5 - * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
     1.6 + * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
     1.7   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     1.8   *
     1.9   * This code is free software; you can redistribute it and/or modify it
    1.10 @@ -55,6 +55,15 @@
    1.11    return calculate_adr_type(adr->bottom_type(), cross_check);
    1.12  }
    1.13  
    1.14 +bool MemNode::check_if_adr_maybe_raw(Node* adr) {
    1.15 +  if (adr != NULL) {
    1.16 +    if (adr->bottom_type()->base() == Type::RawPtr || adr->bottom_type()->base() == Type::AnyPtr) {
    1.17 +      return true;
    1.18 +    }
    1.19 +  }
    1.20 +  return false;
    1.21 +}
    1.22 +
    1.23  #ifndef PRODUCT
    1.24  void MemNode::dump_spec(outputStream *st) const {
    1.25    if (in(Address) == NULL)  return; // node is dead
    1.26 @@ -503,6 +512,7 @@
    1.27    if (offset == Type::OffsetBot)
    1.28      return NULL;            // cannot unalias unless there are precise offsets
    1.29  
    1.30 +  const bool adr_maybe_raw = check_if_adr_maybe_raw(adr);
    1.31    const TypeOopPtr *addr_t = adr->bottom_type()->isa_oopptr();
    1.32  
    1.33    intptr_t size_in_bytes = memory_size();
    1.34 @@ -519,6 +529,13 @@
    1.35        Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
    1.36        if (st_base == NULL)
    1.37          break;              // inscrutable pointer
    1.38 +
    1.39 +      // For raw accesses it's not enough to prove that constant offsets don't intersect.
    1.40 +      // We need the bases to be the equal in order for the offset check to make sense.
    1.41 +      if ((adr_maybe_raw || check_if_adr_maybe_raw(st_adr)) && st_base != base) {
    1.42 +        break;
    1.43 +      }
    1.44 +
    1.45        if (st_offset != offset && st_offset != Type::OffsetBot) {
    1.46          const int MAX_STORE = BytesPerLong;
    1.47          if (st_offset >= offset + size_in_bytes ||

     2.1 --- a/src/share/vm/opto/memnode.hpp	Wed Jun 07 13:59:35 2017 -0400
     2.2 +++ b/src/share/vm/opto/memnode.hpp	Tue Jul 25 10:10:41 2017 -0400
     2.3 @@ -1,5 +1,5 @@
     2.4  /*
     2.5 - * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
     2.6 + * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
     2.7   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     2.8   *
     2.9   * This code is free software; you can redistribute it and/or modify it
    2.10 @@ -75,6 +75,8 @@
    2.11      debug_only(_adr_type=at; adr_type();)
    2.12    }
    2.13  
    2.14 +  static bool check_if_adr_maybe_raw(Node* adr);
    2.15 +
    2.16  public:
    2.17    // Helpers for the optimizer.  Documented in memnode.cpp.
    2.18    static bool detect_ptr_independence(Node* p1, AllocateNode* a1,

     3.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     3.2 +++ b/test/compiler/unsafe/TestRawAliasing.java	Tue Jul 25 10:10:41 2017 -0400
     3.3 @@ -0,0 +1,70 @@
     3.4 +/*
     3.5 + * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
     3.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     3.7 + *
     3.8 + * This code is free software; you can redistribute it and/or modify it
     3.9 + * under the terms of the GNU General Public License version 2 only, as
    3.10 + * published by the Free Software Foundation.
    3.11 + *
    3.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
    3.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    3.14 + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    3.15 + * version 2 for more details (a copy is included in the LICENSE file that
    3.16 + * accompanied this code).
    3.17 + *
    3.18 + * You should have received a copy of the GNU General Public License version
    3.19 + * 2 along with this work; if not, write to the Free Software Foundation,
    3.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    3.21 + *
    3.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    3.23 + * or visit www.oracle.com if you need additional information or have any
    3.24 + * questions.
    3.25 + */
    3.26 +
    3.27 +/*
    3.28 + * @test
    3.29 + * @bug 8178047
    3.30 + * @run main/othervm -XX:CompileCommand=exclude,*.main -XX:-TieredCompilation -XX:-BackgroundCompilation compiler.unsafe.TestRawAliasing
    3.31 + */
    3.32 +
    3.33 +package compiler.unsafe;
    3.34 +
    3.35 +import java.lang.reflect.Field;
    3.36 +
    3.37 +public class TestRawAliasing {
    3.38 +    static private final sun.misc.Unsafe UNSAFE;
    3.39 +    static {
    3.40 +        try {
    3.41 +            Field f = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
    3.42 +            f.setAccessible(true);
    3.43 +            UNSAFE = (sun.misc.Unsafe) f.get(null);
    3.44 +        } catch (Exception e) {
    3.45 +            throw new RuntimeException("Unable to get Unsafe instance.", e);
    3.46 +        }
    3.47 +    }
    3.48 +
    3.49 +    static private final int OFFSET_X = 50;
    3.50 +    static private final int OFFSET_Y = 100;
    3.51 +
    3.52 +    private static int test(long base_plus_offset_x, long base_plus_offset_y, int magic_value) {
    3.53 +        // write 0 to a location
    3.54 +        UNSAFE.putByte(base_plus_offset_x - OFFSET_X, (byte)0);
    3.55 +        // write unfoldable value to really the same location with another base
    3.56 +        UNSAFE.putByte(base_plus_offset_y - OFFSET_Y, (byte)magic_value);
    3.57 +        // read the value back, should be equal to "unfoldable_value"
    3.58 +        return UNSAFE.getByte(base_plus_offset_x - OFFSET_X);
    3.59 +    }
    3.60 +
    3.61 +    private static final int OFF_HEAP_AREA_SIZE = 128;
    3.62 +    private static final byte MAGIC = 123;
    3.63 +
    3.64 +    // main is excluded from compilation since we don't want the test method to inline and make base values fold
    3.65 +    public static void main(String... args) {
    3.66 +        long base = UNSAFE.allocateMemory(OFF_HEAP_AREA_SIZE);
    3.67 +        for (int i = 0; i < 100_000; i++) {
    3.68 +            if (test(base + OFFSET_X, base + OFFSET_Y, MAGIC) != MAGIC) {
    3.69 +                throw new RuntimeException("Unexpected magic value");
    3.70 +            }
    3.71 +        }
    3.72 +    }
    3.73 +}