Mercurial > hg > truffle
view src/share/vm/opto/indexSet.cpp @ 690:d142f1feeed5
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author | acorn |
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date | Sun, 29 Mar 2009 18:19:05 -0400 |
parents | a61af66fc99e |
children | c18cbe5936b8 |
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/* * Copyright 1998-2004 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ // This file defines the IndexSet class, a set of sparse integer indices. // This data structure is used by the compiler in its liveness analysis and // during register allocation. It also defines an iterator for this class. #include "incls/_precompiled.incl" #include "incls/_indexSet.cpp.incl" //-------------------------------- Initializations ------------------------------ IndexSet::BitBlock IndexSet::_empty_block = IndexSet::BitBlock(); #ifdef ASSERT // Initialize statistics counters uint IndexSet::_alloc_new = 0; uint IndexSet::_alloc_total = 0; long IndexSet::_total_bits = 0; long IndexSet::_total_used_blocks = 0; long IndexSet::_total_unused_blocks = 0; // Per set, or all sets operation tracing int IndexSet::_serial_count = 1; #endif // What is the first set bit in a 5 bit integer? const byte IndexSetIterator::_first_bit[32] = { 0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 }; // What is the second set bit in a 5 bit integer? const byte IndexSetIterator::_second_bit[32] = { 5, 5, 5, 1, 5, 2, 2, 1, 5, 3, 3, 1, 3, 2, 2, 1, 5, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1 }; // I tried implementing the IndexSetIterator with a window_size of 8 and // didn't seem to get a noticeable speedup. I am leaving in the tables // in case we want to switch back. /*const byte IndexSetIterator::_first_bit[256] = { 8, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 }; const byte IndexSetIterator::_second_bit[256] = { 8, 8, 8, 1, 8, 2, 2, 1, 8, 3, 3, 1, 3, 2, 2, 1, 8, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 8, 5, 5, 1, 5, 2, 2, 1, 5, 3, 3, 1, 3, 2, 2, 1, 5, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 8, 6, 6, 1, 6, 2, 2, 1, 6, 3, 3, 1, 3, 2, 2, 1, 6, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 6, 5, 5, 1, 5, 2, 2, 1, 5, 3, 3, 1, 3, 2, 2, 1, 5, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 8, 7, 7, 1, 7, 2, 2, 1, 7, 3, 3, 1, 3, 2, 2, 1, 7, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 7, 5, 5, 1, 5, 2, 2, 1, 5, 3, 3, 1, 3, 2, 2, 1, 5, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 7, 6, 6, 1, 6, 2, 2, 1, 6, 3, 3, 1, 3, 2, 2, 1, 6, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1, 6, 5, 5, 1, 5, 2, 2, 1, 5, 3, 3, 1, 3, 2, 2, 1, 5, 4, 4, 1, 4, 2, 2, 1, 4, 3, 3, 1, 3, 2, 2, 1 };*/ //---------------------------- IndexSet::populate_free_list() ----------------------------- // Populate the free BitBlock list with a batch of BitBlocks. The BitBlocks // are 32 bit aligned. void IndexSet::populate_free_list() { Compile *compile = Compile::current(); BitBlock *free = (BitBlock*)compile->indexSet_free_block_list(); char *mem = (char*)arena()->Amalloc_4(sizeof(BitBlock) * bitblock_alloc_chunk_size + 32); // Align the pointer to a 32 bit boundary. BitBlock *new_blocks = (BitBlock*)(((uintptr_t)mem + 32) & ~0x001F); // Add the new blocks to the free list. for (int i = 0; i < bitblock_alloc_chunk_size; i++) { new_blocks->set_next(free); free = new_blocks; new_blocks++; } compile->set_indexSet_free_block_list(free); #ifdef ASSERT if (CollectIndexSetStatistics) { _alloc_new += bitblock_alloc_chunk_size; } #endif } //---------------------------- IndexSet::alloc_block() ------------------------ // Allocate a BitBlock from the free list. If the free list is empty, // prime it. IndexSet::BitBlock *IndexSet::alloc_block() { #ifdef ASSERT if (CollectIndexSetStatistics) { _alloc_total++; } #endif Compile *compile = Compile::current(); BitBlock* free_list = (BitBlock*)compile->indexSet_free_block_list(); if (free_list == NULL) { populate_free_list(); free_list = (BitBlock*)compile->indexSet_free_block_list(); } BitBlock *block = free_list; compile->set_indexSet_free_block_list(block->next()); block->clear(); return block; } //---------------------------- IndexSet::alloc_block_containing() ------------- // Allocate a new BitBlock and put it into the position in the _blocks array // corresponding to element. IndexSet::BitBlock *IndexSet::alloc_block_containing(uint element) { BitBlock *block = alloc_block(); uint bi = get_block_index(element); _blocks[bi] = block; return block; } //---------------------------- IndexSet::free_block() ------------------------- // Add a BitBlock to the free list. void IndexSet::free_block(uint i) { debug_only(check_watch("free block", i)); assert(i < _max_blocks, "block index too large"); BitBlock *block = _blocks[i]; assert(block != &_empty_block, "cannot free the empty block"); block->set_next((IndexSet::BitBlock*)Compile::current()->indexSet_free_block_list()); Compile::current()->set_indexSet_free_block_list(block); set_block(i,&_empty_block); } //------------------------------lrg_union-------------------------------------- // Compute the union of all elements of one and two which interfere with // the RegMask mask. If the degree of the union becomes exceeds // fail_degree, the union bails out. The underlying set is cleared before // the union is performed. uint IndexSet::lrg_union(uint lr1, uint lr2, const uint fail_degree, const PhaseIFG *ifg, const RegMask &mask ) { IndexSet *one = ifg->neighbors(lr1); IndexSet *two = ifg->neighbors(lr2); LRG &lrg1 = ifg->lrgs(lr1); LRG &lrg2 = ifg->lrgs(lr2); #ifdef ASSERT assert(_max_elements == one->_max_elements, "max element mismatch"); check_watch("union destination"); one->check_watch("union source"); two->check_watch("union source"); #endif // Compute the degree of the combined live-range. The combined // live-range has the union of the original live-ranges' neighbors set as // well as the neighbors of all intermediate copies, minus those neighbors // that can not use the intersected allowed-register-set. // Copy the larger set. Insert the smaller set into the larger. if (two->count() > one->count()) { IndexSet *temp = one; one = two; two = temp; } clear(); // Used to compute degree of register-only interferences. Infinite-stack // neighbors do not alter colorability, as they can always color to some // other color. (A variant of the Briggs assertion) uint reg_degree = 0; uint element; // Load up the combined interference set with the neighbors of one IndexSetIterator elements(one); while ((element = elements.next()) != 0) { LRG &lrg = ifg->lrgs(element); if (mask.overlap(lrg.mask())) { insert(element); if( !lrg.mask().is_AllStack() ) { reg_degree += lrg1.compute_degree(lrg); if( reg_degree >= fail_degree ) return reg_degree; } else { // !!!!! Danger! No update to reg_degree despite having a neighbor. // A variant of the Briggs assertion. // Not needed if I simplify during coalesce, ala George/Appel. assert( lrg.lo_degree(), "" ); } } } // Add neighbors of two as well IndexSetIterator elements2(two); while ((element = elements2.next()) != 0) { LRG &lrg = ifg->lrgs(element); if (mask.overlap(lrg.mask())) { if (insert(element)) { if( !lrg.mask().is_AllStack() ) { reg_degree += lrg2.compute_degree(lrg); if( reg_degree >= fail_degree ) return reg_degree; } else { // !!!!! Danger! No update to reg_degree despite having a neighbor. // A variant of the Briggs assertion. // Not needed if I simplify during coalesce, ala George/Appel. assert( lrg.lo_degree(), "" ); } } } } return reg_degree; } //---------------------------- IndexSet() ----------------------------- // A deep copy constructor. This is used when you need a scratch copy of this set. IndexSet::IndexSet (IndexSet *set) { #ifdef ASSERT _serial_number = _serial_count++; set->check_watch("copied", _serial_number); check_watch("initialized by copy", set->_serial_number); _max_elements = set->_max_elements; #endif _count = set->_count; _max_blocks = set->_max_blocks; if (_max_blocks <= preallocated_block_list_size) { _blocks = _preallocated_block_list; } else { _blocks = (IndexSet::BitBlock**) arena()->Amalloc_4(sizeof(IndexSet::BitBlock**) * _max_blocks); } for (uint i = 0; i < _max_blocks; i++) { BitBlock *block = set->_blocks[i]; if (block == &_empty_block) { set_block(i, &_empty_block); } else { BitBlock *new_block = alloc_block(); memcpy(new_block->words(), block->words(), sizeof(uint32) * words_per_block); set_block(i, new_block); } } } //---------------------------- IndexSet::initialize() ----------------------------- // Prepare an IndexSet for use. void IndexSet::initialize(uint max_elements) { #ifdef ASSERT _serial_number = _serial_count++; check_watch("initialized", max_elements); _max_elements = max_elements; #endif _count = 0; _max_blocks = (max_elements + bits_per_block - 1) / bits_per_block; if (_max_blocks <= preallocated_block_list_size) { _blocks = _preallocated_block_list; } else { _blocks = (IndexSet::BitBlock**) arena()->Amalloc_4(sizeof(IndexSet::BitBlock**) * _max_blocks); } for (uint i = 0; i < _max_blocks; i++) { set_block(i, &_empty_block); } } //---------------------------- IndexSet::initialize()------------------------------ // Prepare an IndexSet for use. If it needs to allocate its _blocks array, it does // so from the Arena passed as a parameter. BitBlock allocation is still done from // the static Arena which was set with reset_memory(). void IndexSet::initialize(uint max_elements, Arena *arena) { #ifdef ASSERT _serial_number = _serial_count++; check_watch("initialized2", max_elements); _max_elements = max_elements; #endif // ASSERT _count = 0; _max_blocks = (max_elements + bits_per_block - 1) / bits_per_block; if (_max_blocks <= preallocated_block_list_size) { _blocks = _preallocated_block_list; } else { _blocks = (IndexSet::BitBlock**) arena->Amalloc_4(sizeof(IndexSet::BitBlock**) * _max_blocks); } for (uint i = 0; i < _max_blocks; i++) { set_block(i, &_empty_block); } } //---------------------------- IndexSet::swap() ----------------------------- // Exchange two IndexSets. void IndexSet::swap(IndexSet *set) { #ifdef ASSERT assert(_max_elements == set->_max_elements, "must have same universe size to swap"); check_watch("swap", set->_serial_number); set->check_watch("swap", _serial_number); #endif for (uint i = 0; i < _max_blocks; i++) { BitBlock *temp = _blocks[i]; set_block(i, set->_blocks[i]); set->set_block(i, temp); } uint temp = _count; _count = set->_count; set->_count = temp; } //---------------------------- IndexSet::dump() ----------------------------- // Print this set. Used for debugging. #ifndef PRODUCT void IndexSet::dump() const { IndexSetIterator elements(this); tty->print("{"); uint i; while ((i = elements.next()) != 0) { tty->print("L%d ", i); } tty->print_cr("}"); } #endif #ifdef ASSERT //---------------------------- IndexSet::tally_iteration_statistics() ----------------------------- // Update block/bit counts to reflect that this set has been iterated over. void IndexSet::tally_iteration_statistics() const { _total_bits += count(); for (uint i = 0; i < _max_blocks; i++) { if (_blocks[i] != &_empty_block) { _total_used_blocks++; } else { _total_unused_blocks++; } } } //---------------------------- IndexSet::print_statistics() ----------------------------- // Print statistics about IndexSet usage. void IndexSet::print_statistics() { long total_blocks = _total_used_blocks + _total_unused_blocks; tty->print_cr ("Accumulated IndexSet usage statistics:"); tty->print_cr ("--------------------------------------"); tty->print_cr (" Iteration:"); tty->print_cr (" blocks visited: %d", total_blocks); tty->print_cr (" blocks empty: %4.2f%%", 100.0*_total_unused_blocks/total_blocks); tty->print_cr (" bit density (bits/used blocks): %4.2f%%", (double)_total_bits/_total_used_blocks); tty->print_cr (" bit density (bits/all blocks): %4.2f%%", (double)_total_bits/total_blocks); tty->print_cr (" Allocation:"); tty->print_cr (" blocks allocated: %d", _alloc_new); tty->print_cr (" blocks used/reused: %d", _alloc_total); } //---------------------------- IndexSet::verify() ----------------------------- // Expensive test of IndexSet sanity. Ensure that the count agrees with the // number of bits in the blocks. Make sure the iterator is seeing all elements // of the set. Meant for use during development. void IndexSet::verify() const { assert(!member(0), "zero cannot be a member"); uint count = 0; uint i; for (i = 1; i < _max_elements; i++) { if (member(i)) { count++; assert(count <= _count, "_count is messed up"); } } IndexSetIterator elements(this); count = 0; while ((i = elements.next()) != 0) { count++; assert(member(i), "returned a non member"); assert(count <= _count, "iterator returned wrong number of elements"); } } #endif //---------------------------- IndexSetIterator() ----------------------------- // Create an iterator for a set. If empty blocks are detected when iterating // over the set, these blocks are replaced. IndexSetIterator::IndexSetIterator(IndexSet *set) { #ifdef ASSERT if (CollectIndexSetStatistics) { set->tally_iteration_statistics(); } set->check_watch("traversed", set->count()); #endif if (set->is_empty()) { _current = 0; _next_word = IndexSet::words_per_block; _next_block = 1; _max_blocks = 1; // We don't need the following values when we iterate over an empty set. // The commented out code is left here to document that the omission // is intentional. // //_value = 0; //_words = NULL; //_blocks = NULL; //_set = NULL; } else { _current = 0; _value = 0; _next_block = 0; _next_word = IndexSet::words_per_block; _max_blocks = set->_max_blocks; _words = NULL; _blocks = set->_blocks; _set = set; } } //---------------------------- IndexSetIterator(const) ----------------------------- // Iterate over a constant IndexSet. IndexSetIterator::IndexSetIterator(const IndexSet *set) { #ifdef ASSERT if (CollectIndexSetStatistics) { set->tally_iteration_statistics(); } // We don't call check_watch from here to avoid bad recursion. // set->check_watch("traversed const", set->count()); #endif if (set->is_empty()) { _current = 0; _next_word = IndexSet::words_per_block; _next_block = 1; _max_blocks = 1; // We don't need the following values when we iterate over an empty set. // The commented out code is left here to document that the omission // is intentional. // //_value = 0; //_words = NULL; //_blocks = NULL; //_set = NULL; } else { _current = 0; _value = 0; _next_block = 0; _next_word = IndexSet::words_per_block; _max_blocks = set->_max_blocks; _words = NULL; _blocks = set->_blocks; _set = NULL; } } //---------------------------- List16Iterator::advance_and_next() ----------------------------- // Advance to the next non-empty word in the set being iterated over. Return the next element // if there is one. If we are done, return 0. This method is called from the next() method // when it gets done with a word. uint IndexSetIterator::advance_and_next() { // See if there is another non-empty word in the current block. for (uint wi = _next_word; wi < (unsigned)IndexSet::words_per_block; wi++) { if (_words[wi] != 0) { // Found a non-empty word. _value = ((_next_block - 1) * IndexSet::bits_per_block) + (wi * IndexSet::bits_per_word); _current = _words[wi]; _next_word = wi+1; return next(); } } // We ran out of words in the current block. Advance to next non-empty block. for (uint bi = _next_block; bi < _max_blocks; bi++) { if (_blocks[bi] != &IndexSet::_empty_block) { // Found a non-empty block. _words = _blocks[bi]->words(); for (uint wi = 0; wi < (unsigned)IndexSet::words_per_block; wi++) { if (_words[wi] != 0) { // Found a non-empty word. _value = (bi * IndexSet::bits_per_block) + (wi * IndexSet::bits_per_word); _current = _words[wi]; _next_block = bi+1; _next_word = wi+1; return next(); } } // All of the words in the block were empty. Replace // the block with the empty block. if (_set) { _set->free_block(bi); } } } // These assignments make redundant calls to next on a finished iterator // faster. Probably not necessary. _next_block = _max_blocks; _next_word = IndexSet::words_per_block; // No more words. return 0; }