| /* |
| * Copyright (c) 1998, 2011, 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 |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "opto/chaitin.hpp" |
| #include "opto/compile.hpp" |
| #include "opto/indexSet.hpp" |
| #include "opto/regmask.hpp" |
| |
| // 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. |
| |
| //-------------------------------- Initializations ------------------------------ |
| |
| IndexSet::BitBlock IndexSet::_empty_block = IndexSet::BitBlock(); |
| |
| #ifdef ASSERT |
| // Initialize statistics counters |
| julong IndexSet::_alloc_new = 0; |
| julong IndexSet::_alloc_total = 0; |
| |
| julong IndexSet::_total_bits = 0; |
| julong IndexSet::_total_used_blocks = 0; |
| julong 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 uint8_t 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 uint8_t 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) { |
| inc_stat_counter(&_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) { |
| inc_stat_counter(&_alloc_total, 1); |
| } |
| #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_t) * 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 { |
| inc_stat_counter(&_total_bits, count()); |
| |
| for (uint i = 0; i < _max_blocks; i++) { |
| if (_blocks[i] != &_empty_block) { |
| inc_stat_counter(&_total_used_blocks, 1); |
| } else { |
| inc_stat_counter(&_total_unused_blocks, 1); |
| } |
| } |
| } |
| |
| //---------------------------- IndexSet::print_statistics() ----------------------------- |
| // Print statistics about IndexSet usage. |
| |
| void IndexSet::print_statistics() { |
| julong 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: " UINT64_FORMAT, total_blocks); |
| tty->print_cr (" blocks empty: %4.2f%%", 100.0*(double)_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: " UINT64_FORMAT, _alloc_new); |
| tty->print_cr (" blocks used/reused: " UINT64_FORMAT, _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; |
| } |