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 * 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

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 */

#ifndef SHARE_VM_UTILITIES_COPY_HPP

#define SHARE_VM_UTILITIES_COPY_HPP

#include "runtime/stubRoutines.hpp"

#include "utilities/align.hpp"

#include "utilities/macros.hpp"

// Assembly code for platforms that need it.

extern "C" {

}

class Copy : AllStatic {

 public:

  // Block copy methods have four attributes.  We don't define all possibilities.

  //   alignment: aligned to BytesPerLong

  //   arrayof:   arraycopy operation with both operands aligned on the same

  //              boundary as the first element of an array of the copy unit.

  //              This is currently a HeapWord boundary on all platforms, except

  //              for long and double arrays, which are aligned on an 8-byte

  //              boundary on all platforms.

  //              arraycopy operations are implicitly atomic on each array element.

  //   overlap:   disjoint or conjoint.

  //   copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).

  //   atomicity: atomic or non-atomic on the copy unit.

  //

  // Names are constructed thusly:

  //

  //     [ 'aligned_' | 'arrayof_' ]

  //     ('conjoint_' | 'disjoint_')

  //     ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')

  //     [ '_atomic' ]

  //

  // Except in the arrayof case, whatever the alignment is, we assume we can copy

  // whole alignment units.  E.g., if BytesPerLong is 2x word alignment, an odd

  // count may copy an extra word.  In the arrayof case, we are allowed to copy

  // only the number of copy units specified.

  //

  // All callees check count for 0.

  //

  // HeapWords

  // Word-aligned words,    conjoint, not atomic on each word

    assert_params_ok(from, to, LogHeapWordSize);

    pd_conjoint_words(from, to, count);

  }

  // Word-aligned words,    disjoint, not atomic on each word

    assert_params_ok(from, to, LogHeapWordSize);

    assert_disjoint(from, to, count);

    pd_disjoint_words(from, to, count);

  }

  // Word-aligned words,    disjoint, atomic on each word

    assert_params_ok(from, to, LogHeapWordSize);

    assert_disjoint(from, to, count);

    pd_disjoint_words_atomic(from, to, count);

  }

  // Object-aligned words,  conjoint, not atomic on each word

    assert_params_aligned(from, to);

    pd_aligned_conjoint_words(from, to, count);

  }

  // Object-aligned words,  disjoint, not atomic on each word

    assert_params_aligned(from, to);

    assert_disjoint(from, to, count);

    pd_aligned_disjoint_words(from, to, count);

  }

  // bytes, jshorts, jints, jlongs, oops

  // bytes,                 conjoint, not atomic on each byte (not that it matters)

    pd_conjoint_bytes(from, to, count);

  }

  // bytes,                 conjoint, atomic on each byte (not that it matters)

    pd_conjoint_bytes(from, to, count);

  }

  // jshorts,               conjoint, atomic on each jshort

    assert_params_ok(from, to, LogBytesPerShort);

    pd_conjoint_jshorts_atomic(from, to, count);

  }

  // jints,                 conjoint, atomic on each jint

    assert_params_ok(from, to, LogBytesPerInt);

    pd_conjoint_jints_atomic(from, to, count);

  }

  // jlongs,                conjoint, atomic on each jlong

    assert_params_ok(from, to, LogBytesPerLong);

    pd_conjoint_jlongs_atomic(from, to, count);

  }

  // oops,                  conjoint, atomic on each oop

    assert_params_ok(from, to, LogBytesPerHeapOop);

    pd_conjoint_oops_atomic(from, to, count);

  }

  // overloaded for UseCompressedOops

    assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");

    assert_params_ok(from, to, LogBytesPerInt);

  }

  // Copy a span of memory.  If the span is an integral number of aligned

  // longs, words, or ints, copy those units atomically.

  // The largest atomic transfer unit is 8 bytes, or the largest power

  // of two which divides all of from, to, and size, whichever is smaller.

  // bytes,                 conjoint array, atomic on each byte (not that it matters)

    pd_arrayof_conjoint_bytes(from, to, count);

  }

  // jshorts,               conjoint array, atomic on each jshort

    assert_params_ok(from, to, LogBytesPerShort);

    pd_arrayof_conjoint_jshorts(from, to, count);

  }

  // jints,                 conjoint array, atomic on each jint

    assert_params_ok(from, to, LogBytesPerInt);

    pd_arrayof_conjoint_jints(from, to, count);

  }

  // jlongs,                conjoint array, atomic on each jlong

    assert_params_ok(from, to, LogBytesPerLong);

    pd_arrayof_conjoint_jlongs(from, to, count);

  }

  // oops,                  conjoint array, atomic on each oop

    assert_params_ok(from, to, LogBytesPerHeapOop);

    pd_arrayof_conjoint_oops(from, to, count);

  }

  // Known overlap methods

  // Copy word-aligned words from higher to lower addresses, not atomic on each word

    // byte_count is in bytes to check its alignment

    assert_params_ok(from, to, LogHeapWordSize);

    assert_byte_count_ok(byte_count, HeapWordSize);

    size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;

    assert(to <= from || from + count <= to, "do not overwrite source data");

    while (count-- > 0) {

      *to++ = *from++;

    }

  }

  // Copy word-aligned words from lower to higher addresses, not atomic on each word

    // byte_count is in bytes to check its alignment

    assert_params_ok(from, to, LogHeapWordSize);

    assert_byte_count_ok(byte_count, HeapWordSize);

    size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;

    assert(from <= to || to + count <= from, "do not overwrite source data");

    from += count - 1;

    to   += count - 1;

    while (count-- > 0) {

      *to-- = *from--;

    }

  }

  /**

   * Copy elements

   *

   * @param src address of source

   * @param dst address of destination

   * @param byte_count number of bytes to copy

   * @param elem_size size of the elements to copy-swap

   */

  static void conjoint_copy(const void* src, void* dst, size_t byte_count, size_t elem_size);

  /**

   * Copy and *unconditionally* byte swap elements

   *

   * @param src address of source

   * @param dst address of destination

   * @param byte_count number of bytes to copy

   * @param elem_size size of the elements to copy-swap

   */

  static void conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size);

  /**

   * Copy and byte swap elements from the specified endian to the native (cpu) endian if needed (if they differ)

   *

   * @param src address of source

   * @param dst address of destination

   * @param byte_count number of bytes to copy

   * @param elem_size size of the elements to copy-swap

   */

  template <Endian::Order endian>

  static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) {

    if (Endian::NATIVE != endian) {

      conjoint_swap(src, dst, byte_count, elem_size);

    } else {

      conjoint_copy(src, dst, byte_count, elem_size);

    }

  }

  // Fill methods

  // Fill word-aligned words, not atomic on each word

  // set_words

  static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {

    assert_params_ok(to, LogHeapWordSize);

    pd_fill_to_words(to, count, value);

  }

  static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {

    assert_params_aligned(to);

    pd_fill_to_aligned_words(to, count, value);

  }

  // Fill bytes

  static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {

    pd_fill_to_bytes(to, count, value);

  }

  // Fill a span of memory.  If the span is an integral number of aligned

  // longs, words, or ints, store to those units atomically.

  // The largest atomic transfer unit is 8 bytes, or the largest power

  // of two which divides both to and size, whichever is smaller.

  static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);

  // Zero-fill methods

  // Zero word-aligned words, not atomic on each word

  static void zero_to_words(HeapWord* to, size_t count) {

    assert_params_ok(to, LogHeapWordSize);

    pd_zero_to_words(to, count);

  }

  // Zero bytes

  static void zero_to_bytes(void* to, size_t count) {

    pd_zero_to_bytes(to, count);

  }

 private:

    if (from < to) {

      return pointer_delta(to, from) >= count;

    }

    return pointer_delta(from, to) >= count;

  }

  // These methods raise a fatal if they detect a problem.

#ifdef ASSERT

    if (!params_disjoint(from, to, count))

      basic_fatal("source and dest overlap");

#endif

  }

#ifdef ASSERT

    if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)

      basic_fatal("not aligned");

    if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)

      basic_fatal("not aligned");

#endif

  }

  static void assert_params_ok(HeapWord* to, intptr_t log_align) {

#ifdef ASSERT

    if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)

      basic_fatal("not word aligned");

#endif

  }

#ifdef ASSERT

    if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)

      basic_fatal("not long aligned");

    if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)

      basic_fatal("not long aligned");

#endif

  }

  static void assert_params_aligned(HeapWord* to) {

#ifdef ASSERT

    if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)

      basic_fatal("not long aligned");

#endif

  }

  static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {

#ifdef ASSERT

    if (!is_aligned(byte_count, unit_size)) {

      basic_fatal("byte count must be aligned");

    }

#endif

  }

  // Platform dependent implementations of the above methods.

#include CPU_HEADER(copy)

};

#endif // SHARE_VM_UTILITIES_COPY_HPP