Population count - optimized block-level operation
| 1976 | |
| 1977 | // Population count - optimized block-level operation |
| 1978 | int64_t count_set_bits() const |
| 1979 | { |
| 1980 | // Get direct access to the underlying blocks |
| 1981 | const block_type* blocks = original_bv_->data() + start_block_; |
| 1982 | int64_t num_blocks = end_block_ - start_block_; |
| 1983 | |
| 1984 | int64_t count = 0; |
| 1985 | const auto& features = base::system_report::get_cpu_features(); |
| 1986 | |
| 1987 | // Use the same optimization logic as bit_vector |
| 1988 | if (features.has_popcnt) { |
| 1989 | #ifdef __x86_64__ |
| 1990 | count = count_set_bits_x86_popcnt_blocks(blocks, num_blocks); |
| 1991 | #elif defined(__aarch64__) |
| 1992 | count = count_set_bits_arm_popcnt_blocks(blocks, num_blocks); |
| 1993 | #else |
| 1994 | count = count_set_bits_builtin_blocks(blocks, num_blocks); |
| 1995 | #endif |
| 1996 | } else { |
| 1997 | count = count_set_bits_software_blocks(blocks, num_blocks); |
| 1998 | } |
| 1999 | |
| 2000 | // Adjust for unused bits in last block if it's partial |
| 2001 | if (end_bit_offset_ != 0) { |
| 2002 | block_type last_block_mask = (block_type(1) << end_bit_offset_) - 1; |
| 2003 | block_type unused_block = blocks[num_blocks - 1] & ~last_block_mask; |
| 2004 | #ifdef _MSC_VER |
| 2005 | count -= __popcnt64(unused_block); |
| 2006 | #else |
| 2007 | count -= __builtin_popcountll(unused_block); |
| 2008 | #endif |
| 2009 | } |
| 2010 | |
| 2011 | return count; |
| 2012 | } |
| 2013 | |
| 2014 | // Find operations - map to global indices |
| 2015 | int64_t find_first_set() const |