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 /*

  * Copyright (c) 2005, 2012, 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

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 #ifndef SHARE_VM_UTILITIES_BITMAP_INLINE_HPP

 #define SHARE_VM_UTILITIES_BITMAP_INLINE_HPP

 #include "runtime/atomic.hpp"

 #include "utilities/bitMap.hpp"

 #ifdef ASSERT

 inline void BitMap::verify_index(idx_t index) const {

   assert(index < _size, "BitMap index out of bounds");

 }

 inline void BitMap::verify_range(idx_t beg_index, idx_t end_index) const {

   assert(beg_index <= end_index, "BitMap range error");

   // Note that [0,0) and [size,size) are both valid ranges.

   if (end_index != _size) verify_index(end_index);

 }

 #endif // #ifdef ASSERT

 inline void BitMap::set_bit(idx_t bit) {

   verify_index(bit);

   *word_addr(bit) |= bit_mask(bit);

 }

 inline void BitMap::clear_bit(idx_t bit) {

   verify_index(bit);

   *word_addr(bit) &= ~bit_mask(bit);

 }

 inline bool BitMap::par_set_bit(idx_t bit) {

   verify_index(bit);

   volatile idx_t* const addr = word_addr(bit);

   const idx_t mask = bit_mask(bit);

   idx_t old_val = *addr;

   do {

     const idx_t new_val = old_val | mask;

     if (new_val == old_val) {

       return false;     // Someone else beat us to it.

     }

     const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,

                                                       (volatile void*) addr,

                                                       (void*) old_val);

     if (cur_val == old_val) {

       return true;      // Success.

     }

     old_val = cur_val;  // The value changed, try again.

   } while (true);

 }

 inline bool BitMap::par_clear_bit(idx_t bit) {

   verify_index(bit);

   volatile idx_t* const addr = word_addr(bit);

   const idx_t mask = ~bit_mask(bit);

   idx_t old_val = *addr;

   do {

     const idx_t new_val = old_val & mask;

     if (new_val == old_val) {

       return false;     // Someone else beat us to it.

     }

     const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,

                                                       (volatile void*) addr,

                                                       (void*) old_val);

     if (cur_val == old_val) {

       return true;      // Success.

     }

     old_val = cur_val;  // The value changed, try again.

   } while (true);

 }

 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) {

   if (hint == small_range && end - beg == 1) {

     set_bit(beg);

   } else {

     if (hint == large_range) {

       set_large_range(beg, end);

     } else {

       set_range(beg, end);

     }

   }

 }

 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {

   if (hint == small_range && end - beg == 1) {

     clear_bit(beg);

   } else {

     if (hint == large_range) {

       clear_large_range(beg, end);

     } else {

       clear_range(beg, end);

     }

   }

 }

 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {

   if (hint == small_range && end - beg == 1) {

     par_at_put(beg, true);

   } else {

     if (hint == large_range) {

       par_at_put_large_range(beg, end, true);

     } else {

       par_at_put_range(beg, end, true);

     }

   }

 }

 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {

   bm_word_t* map = _map;

   for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0;

 }

 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) {

   bm_word_t* map = _map;

   for (idx_t i = beg; i < end; ++i) map[i] = 0;

 }

 inline void BitMap::clear() {

   clear_range_of_words(0, size_in_words());

 }

 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {

   if (hint == small_range && end - beg == 1) {

     par_at_put(beg, false);

   } else {

     if (hint == large_range) {

       par_at_put_large_range(beg, end, false);

     } else {

       par_at_put_range(beg, end, false);

     }

   }

 }

 inline BitMap::idx_t

 BitMap::get_next_one_offset_inline(idx_t l_offset, idx_t r_offset) const {

   assert(l_offset <= size(), "BitMap index out of bounds");

   assert(r_offset <= size(), "BitMap index out of bounds");

   assert(l_offset <= r_offset, "l_offset > r_offset ?");

   if (l_offset == r_offset) {

     return l_offset;

   }

   idx_t   index = word_index(l_offset);

   idx_t r_index = word_index(r_offset-1) + 1;

   idx_t res_offset = l_offset;

   // check bits including and to the _left_ of offset's position

   idx_t pos = bit_in_word(res_offset);

   idx_t res = map(index) >> pos;

   if (res != (uintptr_t)NoBits) {

     // find the position of the 1-bit

     for (; !(res & 1); res_offset++) {

       res = res >> 1;

     }

 #ifdef ASSERT

     // In the following assert, if r_offset is not bitamp word aligned,

     // checking that res_offset is strictly less than r_offset is too

     // strong and will trip the assert.

     //

     // Consider the case where l_offset is bit 15 and r_offset is bit 17

     // of the same map word, and where bits [15:16:17:18] == [00:00:00:01].

     // All the bits in the range [l_offset:r_offset) are 0.

     // The loop that calculates res_offset, above, would yield the offset

     // of bit 18 because it's in the same map word as l_offset and there

     // is a set bit in that map word above l_offset (i.e. res != NoBits).

     //

     // In this case, however, we can assert is that res_offset is strictly

     // less than size() since we know that there is at least one set bit

     // at an offset above, but in the same map word as, r_offset.

     // Otherwise, if r_offset is word aligned then it will not be in the

     // same map word as l_offset (unless it equals l_offset). So either

     // there won't be a set bit between l_offset and the end of it's map

     // word (i.e. res == NoBits), or res_offset will be less than r_offset.

     idx_t limit = is_word_aligned(r_offset) ? r_offset : size();

     assert(res_offset >= l_offset && res_offset < limit, "just checking");

 #endif // ASSERT

     return MIN2(res_offset, r_offset);

   }

   // skip over all word length 0-bit runs

   for (index++; index < r_index; index++) {

     res = map(index);

     if (res != (uintptr_t)NoBits) {

       // found a 1, return the offset

       for (res_offset = bit_index(index); !(res & 1); res_offset++) {

         res = res >> 1;

       }

       assert(res & 1, "tautology; see loop condition");

       assert(res_offset >= l_offset, "just checking");

       return MIN2(res_offset, r_offset);

     }

   }

   return r_offset;

 }

 inline BitMap::idx_t

 BitMap::get_next_zero_offset_inline(idx_t l_offset, idx_t r_offset) const {

   assert(l_offset <= size(), "BitMap index out of bounds");

   assert(r_offset <= size(), "BitMap index out of bounds");

   assert(l_offset <= r_offset, "l_offset > r_offset ?");

   if (l_offset == r_offset) {

     return l_offset;

   }

   idx_t   index = word_index(l_offset);

   idx_t r_index = word_index(r_offset-1) + 1;

   idx_t res_offset = l_offset;

   // check bits including and to the _left_ of offset's position

   idx_t pos = res_offset & (BitsPerWord - 1);

   idx_t res = (map(index) >> pos) | left_n_bits((int)pos);

   if (res != (uintptr_t)AllBits) {

     // find the position of the 0-bit

     for (; res & 1; res_offset++) {

       res = res >> 1;

     }

     assert(res_offset >= l_offset, "just checking");

     return MIN2(res_offset, r_offset);

   }

   // skip over all word length 1-bit runs

   for (index++; index < r_index; index++) {

     res = map(index);

     if (res != (uintptr_t)AllBits) {

       // found a 0, return the offset

       for (res_offset = index << LogBitsPerWord; res & 1;

            res_offset++) {

         res = res >> 1;

       }

       assert(!(res & 1), "tautology; see loop condition");

       assert(res_offset >= l_offset, "just checking");

       return MIN2(res_offset, r_offset);

     }

   }

   return r_offset;

 }

 inline BitMap::idx_t

 BitMap::get_next_one_offset_inline_aligned_right(idx_t l_offset,

                                                  idx_t r_offset) const

 {

   verify_range(l_offset, r_offset);

   assert(bit_in_word(r_offset) == 0, "r_offset not word-aligned");

   if (l_offset == r_offset) {

     return l_offset;

   }

   idx_t   index = word_index(l_offset);

   idx_t r_index = word_index(r_offset);

   idx_t res_offset = l_offset;

   // check bits including and to the _left_ of offset's position

   idx_t res = map(index) >> bit_in_word(res_offset);

   if (res != (uintptr_t)NoBits) {

     // find the position of the 1-bit

     for (; !(res & 1); res_offset++) {

       res = res >> 1;

     }

     assert(res_offset >= l_offset &&

            res_offset < r_offset, "just checking");

     return res_offset;

   }

   // skip over all word length 0-bit runs

   for (index++; index < r_index; index++) {

     res = map(index);

     if (res != (uintptr_t)NoBits) {

       // found a 1, return the offset

       for (res_offset = bit_index(index); !(res & 1); res_offset++) {

         res = res >> 1;

       }

       assert(res & 1, "tautology; see loop condition");

       assert(res_offset >= l_offset && res_offset < r_offset, "just checking");

       return res_offset;

     }

   }

   return r_offset;

 }

 // Returns a bit mask for a range of bits [beg, end) within a single word.  Each

 // bit in the mask is 0 if the bit is in the range, 1 if not in the range.  The

 // returned mask can be used directly to clear the range, or inverted to set the

 // range.  Note:  end must not be 0.

 inline BitMap::bm_word_t

 BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const {

   assert(end != 0, "does not work when end == 0");

   assert(beg == end || word_index(beg) == word_index(end - 1),

          "must be a single-word range");

   bm_word_t mask = bit_mask(beg) - 1;   // low (right) bits

   if (bit_in_word(end) != 0) {

     mask |= ~(bit_mask(end) - 1);       // high (left) bits

   }

   return mask;

 }

 inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) {

   memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(uintptr_t));

 }

 inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) {

   memset(_map + beg, 0, (end - beg) * sizeof(uintptr_t));

 }

 inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const {

   idx_t bit_rounded_up = bit + (BitsPerWord - 1);

   // Check for integer arithmetic overflow.

   return bit_rounded_up > bit ? word_index(bit_rounded_up) : size_in_words();

 }

 inline BitMap::idx_t BitMap::get_next_one_offset(idx_t l_offset,

                                           idx_t r_offset) const {

   return get_next_one_offset_inline(l_offset, r_offset);

 }

 inline BitMap::idx_t BitMap::get_next_zero_offset(idx_t l_offset,

                                            idx_t r_offset) const {

   return get_next_zero_offset_inline(l_offset, r_offset);

 }

 inline void BitMap2D::clear() {

   _map.clear();

 }

 #endif // SHARE_VM_UTILITIES_BITMAP_INLINE_HPP