src/share/vm/opto/indexSet.cpp
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@@ -21,557 +21,22 @@
* 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 {
+void IndexSet::dump() {
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;
-}