Mercurial > hg > graal-compiler
diff src/share/vm/opto/indexSet.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/indexSet.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,573 @@ +/* + * 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; +}