src/share/vm/utilities/bitMap.cpp

rev 13451 : imported patch remove_cmpxchg_ptr_users
rev 13475 : imported patch replace_if_null
rev 13477 : imported patch fix_popc_table

*** 208,223 ****
  void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
    assert(value == 0 || value == 1, "0 for clear, 1 for set");
    // With a valid range (beg <= end), this test ensures that end != 0, as
    // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.
    if (beg != end) {
!     intptr_t* pw  = (intptr_t*)word_addr(beg);
!     intptr_t  w   = *pw;
!     intptr_t  mr  = (intptr_t)inverted_bit_mask_for_range(beg, end);
!     intptr_t  nw  = value ? (w | ~mr) : (w & mr);
      while (true) {
!       intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
        if (res == w) break;
        w  = res;
        nw = value ? (w | ~mr) : (w & mr);
      }
    }
--- 208,223 ----
  void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
    assert(value == 0 || value == 1, "0 for clear, 1 for set");
    // With a valid range (beg <= end), this test ensures that end != 0, as
    // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.
    if (beg != end) {
!     bm_word_t* pw = word_addr(beg);
!     bm_word_t  w  = *pw;
!     bm_word_t  mr = inverted_bit_mask_for_range(beg, end);
!     bm_word_t  nw = value ? (w | ~mr) : (w & mr);
      while (true) {
!       bm_word_t res = Atomic::cmpxchg(nw, pw, w);
        if (res == w) break;
        w  = res;
        nw = value ? (w | ~mr) : (w & mr);
      }
    }
*** 615,638 ****
      }
    }
    return true;
  }
  
! BitMap::idx_t* BitMap::_pop_count_table = NULL;
  
  void BitMap::init_pop_count_table() {
    if (_pop_count_table == NULL) {
      BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
      for (uint i = 0; i < 256; i++) {
        table[i] = num_set_bits(i);
      }
  
!     intptr_t res = Atomic::cmpxchg_ptr((intptr_t)  table,
!                                        (intptr_t*) &_pop_count_table,
!                                        (intptr_t)  NULL_WORD);
!     if (res != NULL_WORD) {
!       guarantee( _pop_count_table == (void*) res, "invariant" );
        FREE_C_HEAP_ARRAY(idx_t, table);
      }
    }
  }
  
--- 615,635 ----
      }
    }
    return true;
  }
  
! const BitMap::idx_t* BitMap::_pop_count_table = NULL;
  
  void BitMap::init_pop_count_table() {
    if (_pop_count_table == NULL) {
      BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
      for (uint i = 0; i < 256; i++) {
        table[i] = num_set_bits(i);
      }
  
!     if (!Atomic::replace_if_null(table, &_pop_count_table)) {
!       guarantee(_pop_count_table != NULL, "invariant");
        FREE_C_HEAP_ARRAY(idx_t, table);
      }
    }
  }