| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/compiler/coalesced-live-ranges.h" |
| #include "src/compiler/greedy-allocator.h" |
| #include "src/compiler/register-allocator.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| |
| LiveRangeConflictIterator::LiveRangeConflictIterator(const LiveRange* range, |
| IntervalStore* storage) |
| : query_(range->first_interval()), |
| pos_(storage->end()), |
| intervals_(storage) { |
| MovePosAndQueryToFirstConflict(); |
| } |
| |
| |
| LiveRange* LiveRangeConflictIterator::Current() const { |
| if (IsFinished()) return nullptr; |
| return pos_->range_; |
| } |
| |
| |
| void LiveRangeConflictIterator::MovePosToFirstConflictForQuery() { |
| DCHECK_NOT_NULL(query_); |
| auto end = intervals_->end(); |
| LifetimePosition q_start = query_->start(); |
| LifetimePosition q_end = query_->end(); |
| |
| if (intervals_->empty() || intervals_->rbegin()->end_ <= q_start || |
| intervals_->begin()->start_ >= q_end) { |
| pos_ = end; |
| return; |
| } |
| |
| pos_ = intervals_->upper_bound(AsAllocatedInterval(q_start)); |
| // pos is either at the end (no start strictly greater than q_start) or |
| // at some position with the aforementioned property. In either case, the |
| // allocated interval before this one may intersect our query: |
| // either because, although it starts before this query's start, it ends |
| // after; or because it starts exactly at the query start. So unless we're |
| // right at the beginning of the storage - meaning the first allocated |
| // interval is also starting after this query's start - see what's behind. |
| if (pos_ != intervals_->begin()) { |
| --pos_; |
| if (!QueryIntersectsAllocatedInterval()) { |
| // The interval behind wasn't intersecting, so move back. |
| ++pos_; |
| } |
| } |
| if (pos_ == end || !QueryIntersectsAllocatedInterval()) { |
| pos_ = end; |
| } |
| } |
| |
| |
| void LiveRangeConflictIterator::MovePosAndQueryToFirstConflict() { |
| auto end = intervals_->end(); |
| for (; query_ != nullptr; query_ = query_->next()) { |
| MovePosToFirstConflictForQuery(); |
| if (pos_ != end) { |
| DCHECK(QueryIntersectsAllocatedInterval()); |
| return; |
| } |
| } |
| |
| Invalidate(); |
| } |
| |
| |
| void LiveRangeConflictIterator::IncrementPosAndSkipOverRepetitions() { |
| auto end = intervals_->end(); |
| DCHECK(pos_ != end); |
| LiveRange* current_conflict = Current(); |
| while (pos_ != end && pos_->range_ == current_conflict) { |
| ++pos_; |
| } |
| } |
| |
| |
| LiveRange* LiveRangeConflictIterator::InternalGetNext(bool clean_behind) { |
| if (IsFinished()) return nullptr; |
| |
| LiveRange* to_clear = Current(); |
| IncrementPosAndSkipOverRepetitions(); |
| // At this point, pos_ is either at the end, or on an interval that doesn't |
| // correspond to the same range as to_clear. This interval may not even be |
| // a conflict. |
| if (clean_behind) { |
| // Since we parked pos_ on an iterator that won't be affected by removal, |
| // we can safely delete to_clear's intervals. |
| for (auto interval = to_clear->first_interval(); interval != nullptr; |
| interval = interval->next()) { |
| AllocatedInterval erase_key(interval->start(), interval->end(), nullptr); |
| intervals_->erase(erase_key); |
| } |
| } |
| // We may have parked pos_ at the end, or on a non-conflict. In that case, |
| // move to the next query and reinitialize pos and query. This may invalidate |
| // the iterator, if no more conflicts are available. |
| if (!QueryIntersectsAllocatedInterval()) { |
| query_ = query_->next(); |
| MovePosAndQueryToFirstConflict(); |
| } |
| return Current(); |
| } |
| |
| |
| LiveRangeConflictIterator CoalescedLiveRanges::GetConflicts( |
| const LiveRange* range) { |
| return LiveRangeConflictIterator(range, &intervals()); |
| } |
| |
| |
| void CoalescedLiveRanges::AllocateRange(LiveRange* range) { |
| for (auto interval = range->first_interval(); interval != nullptr; |
| interval = interval->next()) { |
| AllocatedInterval to_insert(interval->start(), interval->end(), range); |
| intervals().insert(to_insert); |
| } |
| } |
| |
| |
| bool CoalescedLiveRanges::VerifyAllocationsAreValidForTesting() const { |
| LifetimePosition last_end = LifetimePosition::GapFromInstructionIndex(0); |
| for (auto i : intervals_) { |
| if (i.start_ < last_end) { |
| return false; |
| } |
| last_end = i.end_; |
| } |
| return true; |
| } |
| |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |