--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/opto/indexSet.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,577 @@
+/*
+ * 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;
+}