From 772d0888efe11e12c6849e44bdda5c0cf58d39ee Mon Sep 17 00:00:00 2001 From: "jan.reininghaus" Date: Tue, 14 May 2013 13:40:15 +0000 Subject: code cleanup git-svn-id: https://phat.googlecode.com/svn/trunk@86 8e3bb3c2-eed4-f18f-5264-0b6c94e6926d --- .../phat/representations/bit_tree_pivot_column.h | 117 ++++++++------------- 1 file changed, 45 insertions(+), 72 deletions(-) (limited to 'include/phat/representations/bit_tree_pivot_column.h') diff --git a/include/phat/representations/bit_tree_pivot_column.h b/include/phat/representations/bit_tree_pivot_column.h index e8746f8..888e338 100644 --- a/include/phat/representations/bit_tree_pivot_column.h +++ b/include/phat/representations/bit_tree_pivot_column.h @@ -30,12 +30,14 @@ namespace phat { // 'add_index' is still the real bottleneck in practice. class bit_tree_column { + protected: + size_t offset; // data[i + offset] = ith block of the data-bitset typedef uint64_t block_type; std::vector< block_type > data; // this static is not a problem with OMP, it's initialized just after program starts - static const size_t debrujin_magic_table[64]; + static const size_t debrujin_magic_table[ 64 ]; enum { block_size_in_bits = 64 }; enum { block_shift = 6 }; @@ -45,118 +47,90 @@ namespace phat { // (-x)&x isolates the rightmost bit. // The whole method is much faster than calling log2i, and very comparable to using ScanBitForward/Reverse intrinsic, // which should be one CPU instruction, but is not portable. - size_t rightmost_pos(const block_type value) const - { - return 64 - 1 - debrujin_magic_table[((value & (-(int64_t)value))*0x07EDD5E59A4E28C2) >> 58]; + size_t rightmost_pos( const block_type value ) const { + return 64 - 1 - debrujin_magic_table[ ( (value & (-(int64_t)value) ) * 0x07EDD5E59A4E28C2 ) >> 58 ]; } - public: + public: - void init(index num_cols) - { + void init( index num_cols ) { int64_t n = 1; // in case of overflow - int64_t bottom_blocks_needed = (num_cols+block_size_in_bits-1)/block_size_in_bits; + int64_t bottom_blocks_needed = ( num_cols + block_size_in_bits - 1 ) / block_size_in_bits; int64_t upper_blocks = 1; // How many blocks/nodes of index needed to index the whole bitset? - while(n * block_size_in_bits < bottom_blocks_needed) - { + while( n * block_size_in_bits < bottom_blocks_needed ) { n *= block_size_in_bits; upper_blocks += n; } offset = upper_blocks; - data.resize(upper_blocks + bottom_blocks_needed, 0); + data.resize( upper_blocks + bottom_blocks_needed, 0 ); } - index get_max_index() const - { - if (!data[0]) + index get_max_index() const { + if( !data[ 0 ] ) return -1; - const size_t size = data.size(); size_t n = 0; - - while(true) - { - const block_type val = data[n]; - const size_t index = rightmost_pos(val); - const size_t newn = (n << block_shift) + index + 1; - - if (newn >= size) - { - const size_t bottom_index = n - offset; - return (bottom_index << block_shift) + index; - } - + size_t newn = 0; + size_t index = 0; + while( newn < data.size() ) { n = newn; - } + index = rightmost_pos( data[ n ] ); + newn = ( n << block_shift ) + index + 1; + } - return -1; + return ( ( n - offset ) << block_shift ) + index; } - bool is_empty() const - { - return data[0] == 0; + bool is_empty() const { + return data[ 0 ] == 0; } - void add_index(const size_t entry) - { + void add_index( const size_t entry ) { const block_type ONE = 1; - const block_type block_modulo_mask = ((ONE << block_shift) - 1); + const block_type block_modulo_mask = ( ONE << block_shift ) - 1; size_t index_in_level = entry >> block_shift; size_t address = index_in_level + offset; size_t index_in_block = entry & block_modulo_mask; - block_type mask = (ONE << (block_size_in_bits - index_in_block - 1)); - - while(true) - { - data[address]^=mask; + block_type mask = ( ONE << ( block_size_in_bits - index_in_block - 1 ) ); - // First we check if we reached the root. - // Also, if anyone else was in this block, we don't need to update the path up. - if (!address || (data[address] & ~mask)) - return; + data[ address ] ^= mask; + // Check if we reached the root. Also, if anyone else was in this block, we don't need to update the path up. + while( address && !( data[ address ] & ~mask ) ) { index_in_block = index_in_level & block_modulo_mask; index_in_level >>= block_shift; --address; address >>= block_shift; - mask = (ONE << (block_size_in_bits - index_in_block - 1)); + mask = ( ONE << ( block_size_in_bits - index_in_block - 1 ) ); + data[ address ] ^= mask; } } - void get_col_and_clear(column &out) - { - out.clear(); - while(true) - { - index mx = this->get_max_index(); - if (mx == -1) - break; - out.push_back(mx); - add_index(mx); + void get_col_and_clear( column &out ) { + index mx = this->get_max_index(); + while( mx != -1 ) { + out.push_back( mx ); + add_index( mx ); + mx = this->get_max_index(); } - std::reverse(out.begin(), out.end()); + std::reverse( out.begin(), out.end() ); } - void add_col(const column &col) - { - for (size_t i = 0; i < col.size(); ++i) - { + void add_col(const column &col) { + for( size_t i = 0; i < col.size(); ++i ) add_index(col[i]); - } } void clear() { - while(true) - { - index mx = this->get_max_index(); - if (mx == -1) - break; - add_index(mx); + index mx = this->get_max_index(); + while( mx != -1 ) { + add_index( mx ); + mx = this->get_max_index(); } } @@ -164,19 +138,18 @@ namespace phat { add_index( get_max_index() ); } - void set_col( const column& col ) { + void set_col( const column& col ) { clear(); add_col( col ); } - void get_col( column& col ) { - col.clear(); + void get_col( column& col ) { get_col_and_clear( col ); add_col( col ); } }; - const size_t bit_tree_column::debrujin_magic_table[64] = { + const size_t bit_tree_column::debrujin_magic_table[ 64 ] = { 63, 0, 58, 1, 59, 47, 53, 2, 60, 39, 48, 27, 54, 33, 42, 3, 61, 51, 37, 40, 49, 18, 28, 20, -- cgit v1.2.3